4 Percutaneous management of intraperitoneal, hepatic and other fluid collections R. F. DONDELINGER J. C. KURDZIEL J. BOVERIE
PATHWAYS
OF SPREAD OF INFECTION
Percutaneous imaging-guided treatment of abdominal fluid collections and abscesses has been considered the most prominent advance in abdominal surgery in the past decade. Intraperitoneal abscesses usually result from abdominal surgery, insufficiently treated peritonitis or conservative management of trauma. Percutaneous, non-operative management of intraperitoneal abscesses necessitates an understanding of peritoneal compartments and of pathways of spread of infection. This knowledge determines the catheter approach and indicates the intraperitoneal source of infection (Meyers, 1970, 1973). Spread of infected fluid through the peritoneal cavity is dictated by the site, volume, speed of extension, virulence of the micro-organism, peritoneal compartmentalization, pyogenic membrane formation, gravity, position of the patient and intra-abdominal pressure gradients. Diaphragmatic excursion during respiration and abdominal wall movements is responsible for a lower hydrostatic pressure in the subphrenic spaces, compared with the other peritoneal compartments. The intraperitoneal pressure gradient extending from the pelvis to the diaphragm is responsible for the ascending migration of fluid. After laparotomy, pressure gradients are temporarily compromised by the limited movements of the diaphragm and the abdominal wall. Fluid originating from the inframesocolic spaces flows to the pelvic recesses (cul-de-sac) owing to gravity, and accounts for the prevalence of residual abscesses in the pelvis after peritonitis. Pelvic fluid can overspill laterally to the paracolic gutters and ascend due to pressure gradients. The right paracolic gutter is most often filled and allows fluid to spread to the right subhepatic space. Abscess formation in the right anterior subhepatic space is unusual. The hepatorenal fossa or right posterior subhepatic space (Morison’s pouch) represents the most frequent site of infection spread from the inframesocolic space. Fluid cannot escape posteriorly from Morison’s pouch because of the coronary ligament; it spreads anteriorly and laterally BailliPre’s Clinical GastroenterologyVol. 6, No. 2, June 1992 ISBN 0-7020-162>3
273 Copyright 0 1992, by Baillitre All rights of reproduction in any form
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around the inferior border of the liver to the right subphrenic space. Rapid formation of pyogenic membranes can limit the infection to Morison’s pouch. A peritoneal abscess in the right subphrenic space is almost always secondary to a previous contamination of Morison’s pouch, and may be associated with an abscess in that compartment. The dynamics of intraperitoneal fluid explain the prevalence of right subhepatic, Morison’s pouch and subphrenic abscesses in series with predominant appendiceal abscesses (Ochsner and De Bakey, 1938; Altemeier et al, 1973,1979). Left subphrenic abscesses are generally secondary to infected fluid originating from the stomach or spleen or following gastric or splenic surgery. Anastomotic leakage is a frequent cause of left subphrenic abscess formation. The enlarging abscess has two possible pathways of extension: beyond the midline, behind the border of the falciform ligament to the right subphrenic space; or to the pelvis along the left paracolic gutter, with possible ascent to the perihepatic spaces. Extension of infection from the left paracolic gutter to the left subphrenic space is rare when the phrenicolic ligament is intact, but can occur after surgery (Meyers, 1970). Abscess formation in the left subhepatic space is unusual and results generally from breakdown of the lesser omentum, following biliary or pyloric surgery. Lesser sac abscesses are mainly secondary to an infection of an adjacent organ, because the foramen of Winslow is rapidly closed by pyogenic membranes, which prevent contamination from the peritoneal cavity.
BACTERIOLOGY
Any micro-organism, in particular germs originating from the gastrointestinal flora, can participate in pyogenic peritoneal abscesses. Bacteriology of peritoneal abscesses was dominated in the past by Escherichia coli, Staphylococcus aureus and aerobic streptococci. Aerobic gramnegative bacteria are now being cultured with increasing frequency, especially Klebsiella spp, Enterobacter spp, Proteus spp and Pseudomonas spp. Progress in culturing techniques of anaerobes has increased the findings of gram-negative anaerobic bacilli, anaerobic cocci and clostridia, which are present in the gastrointestinal tract. In fact, almost all intraperitoneal abscesses are polymicrobial and contain a mixture of obligatory anaerobes and facultative aerobes. This association seems to be necessary to produce an abscess on an experimental basis (Weinstein et al, 1974). Although treatment of only one of the synergistic bacteria may be curative, best results are obtained when a combination of antibiotics is used for polymicrobial abscesses. Targeted systemic antibiotic therapy is the key to the success of percutaneous abscess drainage. Mycotic abscesses can occur after violation of the digestive mucosa, and are associated with predisposing factors such as central venous catheters, broad-spectrum antibiotics, parenteral alimentation, ol-adrenergic Hz-receptor blockers/antacids, malnutrition, alcoholism, steroids and chemotherapy.
PERCUTANEOUS
SELECTION
MANAGEMENT
OF FLUID
OF FLUID
COLLECTIONS
275
COLLECTIONS
Any localized intraperitoneal fluid collection suspected to be an abscess should be aspirated percutaneously for bacteriological, chemical and cytological tests. If there is no evidence of altered leucocytes and the Gram stain is negative, a drainage catheter is usually not required. When aspiration of fluid confirms pus or the presence of numerous bacteria, single or repeat aspiration or curative percutaneous catheter drainage is performed. Posttraumatic abscesses, resulting from blunt or penetrating injury, should undergo percutaneous treatment as a first choice (Styllianos et al, 1989). Sterile fluid collections such as bilomas or pseudocysts should be drained to prevent recurrence when they are large or communicating. Postoperative collections are not necessarily infected. Following hepatic resection, for instance, fluid accumulation may be seen in 40%; it is often amicrobial, and should be treated, when persistent, by short-term percutaneous drainage, to avoid later abscess formation (Pace et al, 1989). A 7-9 FG drainage catheter is generally adequate, except for recent haematomas with blood clots. Haematomas enlarge during the first few weeks, after which they liquefy, resulting in a fluid accumulation that renders their aspiration easier. Many post-traumatic intraparenchymal haematomas resolve spontaneously. If a haematoma persists, single or repeat percutaneous aspirations are generally curative. During early experience with this technique, percutaneous drainage was restricted to unique, well-defined and non-fistulized abscesses. In the early 198Os, so-called complex abscesses (multiloculated, fistulized or multiple) were considered a contraindication for percutaneous treatment; however, they are now included in many clinical trials. The absence of an anatomical window for the percutaneous approach is a contraindication for catheter abscess drainage. Sedation and correction of abnormal coagulation parameters enable most patients to be treated. Necrotized superinfected tumours should not be drained, as the results are always disappointing. Perivascular or periprosthetic abscesses and tubo-ovarian abscesses raise special problems, but are amenable to percutaneous management in highrisk patients (Matley et al, 1991). Tuberculous abscess in human immunodeficiency virus infection may also be amenable to percutaneous drainage (Bascunana et al, 1990). SELECTION
OF PATIENTS
AND PROGNOSIS
Causes of mortality secondary to treatment of abdominal abscesses are due less to technical failure than to patient risk factors, including age greater than 60 years, multiorgan failure before or after drainage, diagnostic delay, abscesses that remained undiagnosed, recurrence and specific anatomical sites (lesser sac, retroperitoneal space) (Connell et al, 1980; Fry et al, 1980; Deveney et al, 1988). The decreasing incidence of predrainage multiorgan failure is a consequence of earlier diagnosis by cross-sectional imaging. If diagnostic delay is defined as the time period from the causal factor to the time of diagnosis, a delay of 13 days was observed for peritoneal abscesses,
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38 days for retroperitoneal abscesses and 48 days for pelvic abscesses (Dondelinger et al, 1987). These delays are lower than those reported in the surgical literature, which often exceed 1 month, and were defined as the time interval between the onset of clinical symptoms and diagnosis. Better understanding of the role of anaerobic bacteria in the pathogenesis of intraabdominal infection, progress in resuscitation and in antibiotic therapy are other factors responsible for improvements in the treatment of abdominal abscesses. The APACHE II score is helpful in determining the outcome of treatment of abdominal abscesses, by surgical or percutaneous drainage (Hemming et al, 1991; Levison and Zeigler, 1991). The use of ultrasonography and computerized tomography to establish the diagnosis, before single or multiple organ failure has occurred, is one of the greatest advances in abscess treatment (Fry et al, 1980; Hoogewood et al, 1986). Computerized tomography (CT) is the most sensitive and specific method for detection and localization of an abdominal abscess when used as a single test, and in cases of disagreement between different imaging modalities (Kleinhaus et al, 1982; Moir and Robins, 1982; Jasinski et al, 1987; Deveney et al, 1988; Machiedo and Suval, 1988). It is particularly helpful in patients with few symptoms (Werner et al, 1990). Ultrasonography is slightly less sensitive and specific, and rarely adds to the information obtained by CT (Doust and Thompson, 1978); however, it is useful if bedside diagnosis and drainage is required, or for access to the subphrenic and pelvic compartments. Mortality increases when initial drainage is a failure. This raises questions regarding the role of ‘temporizing’ percutaneous drainage. Temporizing percutaneous drainage is a dangerous concept, as it cannot always be defined before starting treatment. Unsuccessful temporizing is merely time lost, while the general condition of the patient deteriorates rapidly. Certain patients, even in poor general condition, should therefore be operated upon, when total cure can be expected by a single operation (Werner et al, 1990). The types of abscess in which drainage is often unsuccessful include infected haematoma, diffuse abscess and pancreatitis (Berger et al, 1989). Fistulized abscesses detected by delayed contrast sinograms usually do not increase mortality, but lead to a change in catheter management or to delayed surgery, when closure of the fistula is not obtained (Berger et al, 1989). Finally, errors in drainage technique and catheter management may account for the vast majority of failures of percutaneous drainage, which raises the problem of education and training in interventional imagingguided procedures (Lang et al, 1986). TECHNICAL
CONSIDERATIONS
Percutaneous aspiration and drainage are mainly performed under ultrasonographic or CT control. When percutaneous treatment of an intraperitoneal fluid collection is considered, special attention should be given to the most direct access to the fluid collection. Previous surgical reports have emphasized the significant difference in morbidity and mortality when an
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extraperitoneal approach was used compared with a transperitoneal approach. Large laparotomy carries a higher risk for infectious spread to previously uncontaminated compartments. Therefore, the percutaneous access route should be defined on cross-sectional images in such a way that approach remains extraperitoneal with direct puncture of the peritoneal abscess. A minimal number of peritoneal compartments should be crossed by the catheter, and large vessels, nerves and solid organs should be avoided. In the authors’ experience, CT imaging enabled percutaneous puncture solely of the peritoneal compartment that contained the abscess in 91% of patients. Nine per cent of abscesses were reached by crossing another compartment, not previously involved in the spontaneous spread of the infectious process. Secondary infection of that compartment did not occur (Dondelinger et al, 1987). Although no complication was observed when solid organs or bowel were penetrated by a 7-FG drainage catheter, every effort should be made to achieve an ideal anatomical approach to the abscess. Failure to define an appropriate percutaneous route to a peritoneal abscess is rare (less than 1%). Most interloop abscesses can be punctured with a safe percutaneous catheter insertion, sometimes only after changing the position of the patient to allow a convenient percutaneous approach, by displacing adjacent mobile structures. Ultrasonography is optimal for imaging of the diaphragm and enables the radiologist to plan a subdiaphragmatic access route when subphrenic abscesses are drained. (Gerzof, 1981; Mueller et al, 1986). The lateral extent of right subphrenic abscesses caudal to the lateral pleural sulcus allows puncture of the collection with CT control and placement of the catheter in the upper portion of the subphrenic space over a guide wire with fluoroscopic control. In specific cases, a ‘triangulation’ approach (Gerzof, 1981a; vansonnenberg et al, 1981) can be used. There is a tendency to prefer a one-step aspiration to a more complex catheter insertion with the Seldinger technique when ultrasound is used as a guiding modality; however, this appears to be associated with a higher rate of recurrences (Civardi et al, 1990). The tip of the catheter should be placed in the most dependent part of the cavity or in a position where maximum negative pressure is expected. A Teflon sheathed needle or trocar (l&gauge or 5FG) is preferred to a 22-gauge needle for diagnostic fluid aspiration, as the needle must be large enough to allow aspiration of viscous pus. The drainage catheter can be inserted with the Seldinger technique over a guide wire through the diagnostic needle, avoiding another puncture. The authors prefer the trocar technique, with a 9-14FG pigtail or straight catheter, whenever a safe percutaneous access is possible. The trocar technique reduces percutaneous manipulation compared with the Seldinger technique and avoids peritoneal leakage of pus. The single-step trocar technique removes the need for repeated passage of dilators over the guide wire along the drainage track with the potential risk of spilling pus, which may lead to infection of other compartments and the subcutaneous tissue. Dilation of the track may, however, be necessary when the abscess has a strong capsule. The calibre of the drainage catheter must be adapted to the viscosity of the drained pus. Surgeons often advocate the use of large-bore catheters, whereas radiologists may refrain from using these catheters, claiming that
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larger catheters do not improve the results of percutaneous drainage (Gobien et al, 1985). Subcutaneous abscesses can occur at the entry site of the catheter following a difficult insertion and usually do not resolve until the drainage material has been removed. Suturing the catheter to the skin is mandatory to prevent inadvertent displacement. Self-retaining catheter devices should not be used. Catheter patency is maintained by four to six daily gentle injections of 5 ml saline through the catheter. Irrigation of the abscess cavity is not recommended as it is associated with septic complications and prolongs the duration of drainage (Dondelinger et al, 1987). The efficacy of antibiotics or mucolytic agents injected in the abscess has not been proved. Gentle suction can be applied to the drainage catheter, but gravity-dependent drainage is usually sufficient. Some patients can be discharged from the hospital with the drainage catheter in place, thus reducing costs (Rifkin et al, 1985). Efficient percutaneous drainage leads to rapid improvement of the patient’s general condition, decrease of fever with temperature normalizing in 4 days, and significant improvement in local pain and tenderness. When there is no clinical change 48-72 hours after a percutaneous drainage catheter has been correctly placed, treatment is probably inadequate. Contrast sinograms or cross-sectional imaging of the drained abscess cavity are performed when the clinical evolution is not favourable, with persistent fever, bacteraemia and leucocytosis, or undiminished or increased drainage output. Contrast medium should not be injected with a pressure higher than the hepatic venous pressure to avoid haematogenous spread of infection and pericatheter spilling of pus which can lead to peritonitis. The drainage is stopped and the catheter is withdrawn 2 days after decrease of drainage to 5-lOm1, defervescence and normalization of leucocytosis. RESULTS Many non-randomized studies have compared the results of percutaneous and surgical drainage (Table 1). Considerable variations among studies are observed, but the techniques are equivalent in terms of initial drainage success, morbidity, mortality and length of hospital stay. Several reports suggest that percutaneous drainage may be superior for specific sites, such as subphrenic abscesses (Johnson et al, 1981; Van Gansbeke et al, 1989). Some anatomic sites are associated with a high mortality risk (Fry et al, 1980). Mortality from percutaneous drainage appears to be lower than following surgical drainage, but results vary with selection of patients. The optimal indication is a well-defined, single, non-fistulized primary hepatic or renal abscess; the worst case is a deeply located, multiloculated and fistulized abscess in an immunocompromised patient. Experience from the literature and results from a personal prospective series indicate that complex abscesses can be drained percutaneously with good results, but they require more attention during treatment (vansonnenberg et al, 1984; Dondelinger et al, 1987). In the latter study, percutaneous drainage was performed in all abdominal abscesses diagnosed. This series included 50%
PERCUTANEOUS Table
1.
MANAGEMENT
279
COLLECTIONS
Results of surgical and percutaneous treatment of peritoneal abscess.
Author Johnson et al (1981) Aeder et al (1983) Brolin et al (1984) Glass and Cohn (1984) Olak (1986) Moessner (1986) Lurie et al (1987) Deveney et al (1988) Total
OF FLUID
Drainage
Patients n
PD SD PD SD PD SD PD SD PD SD PD SD PD SD PD SD
27 43 10 31 24 24 15 44 27 27 21 25 29 60 29 37
PD SD
182 291
Success Complications % % 89 70 69 92 87 47 88 70 85 75 64 80 81 72 78 78.5 76.5
4 16 15 56 8 21 6 23 41 30 60 -
Mortality % 11 21 23 37 12
Drainage duration (days) 17 29 12 21
-
-
-
11 7 13 16 17 17 21 22
31 16 27 34 36 33
10 22
13 16.5
30 33
PD, percutaneous drainage; SD, surgical drainage.
of multiple or complex (fistulized or multilocular) abscesses. Percutaneous drainage was successful in 88% of single, unilocular abscesses and in 63% of complex abscesses. The mortality rate was 33% in patients undergoing operations for failure of percutaneous drainage. The overall success rate was 70% (Dondelinger et al, 1987). These results are consistent with other reports (Gerzof et al, 1985; Lameris et al, 1987). Multiple or complex abscesses can be treated with a temporizing drainage in 11% of cases of peritoneal abscess and in 36% of retroperitoneal abscesses (vansonnenberg et al, 1984b). Depending on the cause of the abscess, secondary surgical treatment may become necessary (i.e. repair of an anastomotic leak). Percutaneous abscess drainage successfully replaces the first operation of a two-step surgical procedure, when hollow viscus perforation is the cause of abscess (Flancbaum et al, 1990). Another interventional treatment can become necessary: diversion of a high-output enteric fistula, biliary or urinary drainage. Successful treatment of abscesses caused by biliary, small bowel and gastric fistulae, as well as anastomotic leaks, has been reported and in these situations percutaneous drainage is a reasonable therapy of first choice in selected patients (Van Waes et al, 1983; Gerzof et al, 1985). Recurrent or persistent abscesses are associated with a high surgical mortality (Altemeier et al, 1973; Fry et al, 1980) because of the necessity of repeat laparotomy and a potential decrease of immunity due to prolonged sepsis. A mortality rate of 50% was reported after surgical treatment of recurrent abscesses. In the authors’ experience, 20% of patients with recurrent abdominal abscess died after a second percutaneous drainage. Abscesses that persist after a failed percutaneous attempt should be
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operated upon rapidly before sepsis becomes generalized, as surgical debridement may in such cases be the only way to cure the patient. LIVER
ABSCESS
The incidence of liver abscess is unknown. The number of cases reported in the recent radiological literature is 1.8 times higher than the number reported per year in the surgical literature. The sensitivity of detection has improved with the increasingly widespread use of ultrasonography and CT since the mid-1970s (Dondelinger et al, 1990). Pyogenic liver abscesses are now diagnosed easily, even when small, although the time interval from the causal event to diagnosis and treatment is uncertain in many cases and can exceed several years, particularly after liver trauma. The sensitivity of ultrasound and CT imaging in the detection of hepatic abscesses is 76% and 85% respectively (Jasinski et al, 1987). Pyogenic abscesses are of biliary, portal, arterial or hepatic origin, or they are due to spread from infection adjacent to the liver. The aetiologic factors have changed over the years: in early surgical reports, appendicitis was responsible for one-third of liver abscesses. In radiological reports (McFadzean et al, 1953; Berger and Osborne, 1982; Kuligowska et al, 1982; Dahnert et al, 1983; Bernardino et al, 1984; Johnson et al, 1985; Gerzof et al, 1985; McCorkell and Niles, 1985; Attar et al, 1986; Bertel et al, 1986; Gyorffy et al, 1987; Sperling et al, 1987; Farges et al, 1988; Pelissier and Ranieri, 1989; Dondelinger et al, 1990) abdominal and biliary surgery account for 27-55% of hepatic abscesses, but in 7-30% no precise cause of liver abscess could be found. It is stressed that bacteria cultured from blood are not necessarily confirmed from pus aspirated from the liver abscess. No specific bacteriologic pattern of hepatic abscess has emerged, but anaerobes are encountered more often than in abscesses in general. Hepatic abscesses are unimicrobial in 27-78%, polymicrobial in 7-47% and amicrobial in O-27% (Dondelinger et al, 1990). Amicrobial abscesses may occur more frequently following systematic antibiotic therapy. During the preantibiotic era, unrecognized pyogenic liver abscesses were associated with a mortality of almost 100%. Surgical management reduced overall mortality to 50-70% over the years. Mortality resulting from surgical treatment was reduced to O-25% for a single abscess when adequate drainage was established, and to 20-40% or higher, when multiple abscesses were present (Bertel et al, 1986; Sperling et al, 1987; Farges et al, 1988). The main reasons for better surgical prognosis of hepatic abscess (as for other abscess locations) were early recognition and refinements in antibiotic therapy and supportive care. Since the first report (McFadzean et al, 1953) demonstrating closed percutaneous management of liver abscess as a valuable alternative to surgical drainage, many case reports of percutaneous aspiration and drainage of liver abscess with ultrasonographic or CT guidance have been published, and have recently been reviewed (Dondelinger et al, 1990). An analysis of 252 patients from 15 published reports showed a male/female ratio of 2.13. The predominance of male patients was found in the earlier surgical reports but not in later
PERCUTANEOUS
MANAGEMENT
OF FLUID
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281
surgical studies because of the growing frequency of biliary disease (responsible for liver abscess) which is more common in females. The mean age of patients overall was 43.6 years, which is lower than in surgical reports. The right lobe of the liver was affected in 80% of patients, the left lobe in 16% of patients and both lobes in 4% of patients. Single pyogenic abscesses were treated in 76% of patients and multiple abscesses in 24%. The small number of patients with multiple abscesses probably reflects the initial restriction of percutaneous drainage to cases of solitary abscess. In the surgical literature, patients with multiple abscesses almost equal the number of patients with solitary abscess (Farges et al, 1988). The average duration of drainage of liver abscesses was 19.5 days. A single aspiration followed by antibiotic therapy was sufficient in some patients; however, several aspirations were required when the volume was large. Initial unsuccessful aspiration was usually followed by percutaneous drainage. Ultrasound was usually the preferred method of guidance for percutaneous treatment. When CT was used as the guidance modality percutaneous catheter drainage was achieved in 87% of patients. When ultrasound and CT were used together, all patients were drained. When ultrasound was used as the guidance modality, an overall success rate of 86% was achieved, when CT was used, the success rate was 82%; and when both modalities were used, a success rate of 55% was observed-66% when the pessimistic study of McCorkell and Niles (1985) was excluded. These figures reflect the preference for ultrasonography for percutaneous aspiration in less critical patients. Successful percutaneous treatment was achieved in 90% of cases of solitary hepatic abscess and in 74% of multiple abscesses, the overall success rate being 77%. These figures are consistent with data from the surgical literature. Multiple liver abscess seems to be associated with critical underlying disease. The ratio of primary abscesses to secondary abscesses was 5.3. Primary liver abscesses, which develop in ‘normal’ liver parenchyma, were successfully treated in 81%. Secondary liver abscesses were defined as superinfection of a pre-existing circumscribed hepatic lesion. They were almost unknown in the early surgical reports and represent 16% of abscesses treated radiologically. Secondary liver abscesses include superinfection of primary and secondary malignant liver tumours, lymphoma and leukaemic infiltration, hepatic cysts, polycystic disease in renal transplant patients, hydatid cyst, haematoma, contusion, necrosis following arterial embolization or chemotherapy. Patients with a secondary hepatic abscess are often referred for percutaneous treatment when they are critically ill and have become poor surgical candidates. In these patients, infection can only be treated percutaneously with large-bore catheters which are able to drain necrotic debris. Prolonged percutaneous drainage is expected and accounts for long hospital stays. When surgery is able to cure the infected hepatic lesion, these patients should be operated on without previous percutaneous drainage. Success of percutaneous drainage of secondary hepatic abscesses is 60%. No randomized series comparing percutaneous and surgical drainage of pyogenic liver abscess is available in the literature. Two radiologcal studies are prospective, as all patients with liver abscess had radiological treatment as a first
2. Results
of surgical
86(n
Sperling 197+1986et al (1987)
= 29)
83 (n = 23)
(n = 22)
90.5 (n = 21)
Surgery
Success
and percutaneous
Bertel et al (1986) 1971-1984
1978-1986
Farges et al (1988) 1966-1977 (n = 24)
Table
treatment
74(n
81(n = 27)
= 16)
72 (n = 18)
Percutaneous treatment
(%)
14
17
0
24
Surgery
of pyogenic
0
13
0
Percutaneous treatment
(%)
abscess.
Death
liver
47
48
29
Surgery
(%)
33
69
20
Percutaneous treatment
Complications
26days
Equal
Surgery
Hospital
46 days
Percutaneous treatment
stay
P WI
PERCUTANEOUS
MANAGEMENT
OF FLUID
COLLECTIONS
283
choice during the time of study; an overall success rate of 84% and a mortality rate of 9% were reported (Gerzof et al, 1985; Dondelinger et al, 1990). Comparison of the most optimistic report (McFadzean et al, 1953) and the most pessimistic report (McCorkell and Niles, 1985) shows the influence of patient selection on outcome. The mean age of the patients in the series of McFadzean et al was 18 years and no one had a debilitating underlying disease; the repeat aspiration success rate was 100%. On the other hand, in the series of McCorkell and Niles, 2 patients had multiple abscesses, 3 had infected ruptured hydatid cyst, 1 had a hepatoma and 1 had acute leukaemia. The mean age was 37 years; overall success rate was 10% and mortality rate was 50%. In three series, surgical results are compared with percutaneous drainage (Bertel et al, 1986; Sperling et al, 1987; Farges et al, 1988) (Table 2). Similar results were obtained with both methods but the advantage of percutaneous treatment was obvious in the postoperative period, in complex situations, in high-risk patients, when the patients could benefit from a temporizing drainage, provided the general condition of the patient improved. Percutaneous drainage could be established with equal ease in either lobe of the liver. The need for resection of an abscess located in the left lobe was obviated. Further accumulation of fluid in the abscess cavity after initial successful aspiration or drainage was not an indication for surgical revision. The reaccumulated fluid is often amicrobial and a second aspiration or a mini-drainage of several days should be performed. Some cavities, such as surgically treated hydatid cysts, do not collapse and are prone to fluid reaccumulation. Biliary fistulae, which are frequently observed in secondary liver abscesses following trauma, will generally close after prolonged drainage, provided there is no persistent biliary obstruction. Failure of percutaneous treatment of liver abscess may be caused by many factors. Technical errors leading to interruption or failure of percutaneous drainage are rare. Septic contamination of the pleura and peritoneum can occur during percutaneous drainage, but patients with perihepatic ascites are at particular risk for peritonitis. The overall death rate was 6.2%, which is similar to surgical results. Half of the patients who died had subsequent surgery. They were cancer patients or had infected echinococcal cysts. Considering patients in series with fewer than 10 patients per series percutaneously treated and including amoebic abscesses, a success rate of 93% and a mortality rate of 3% was found, which reflects patient and abscess selection. Identical figures from the literature are found in another report (Gerzof et al, 1985). It is advocated that patients under 40 years old, who are not debilitated, are not critically ill and who are without evident causal disease should undergo simple aspiration and medical treatment of their liver abscess. Also patients with multiple abscesses smaller than 2cm in diameter and miliary abscesses can benefit from this treatment. Older patients with large abscesses and with another persistent disease should be drained (Figure 1). Subcapsular abscesses are often secondary to a preexisting collection; they will not be reached by antibiotics and should also be drained. Abscesses resulting from biliary obstruction and secondary abscesses should be drained. Failed percutaneous drainage should lead to surgery, before sepsis becomes generalized. Surgery should not be delayed
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for infected hepatic tumours, when an operation can cure the patient, for tre atment of a source of abdominal infection, when an abscess has ruptu red intl o the peritoneal cavity or when peritonitis has occurred due to inadequ Pe’xutaneous manipulation.
(4
PERCUTANEOUS
MANAGEMENT
OF FLUID
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285
(4 1. A 73-year-old male underwent cholecystectomy and choledocho-duoI denalanastomosis for bile stones. Two weeks after surgery, he developed sepsis and cholestasas. (4 Abdominal CT showed a septated 8 cm abscess in the right lobe of the liver. (b) Percuta mt:ous abscess drainage was achieved with a 12-FG vansonnenberg sump catheter under ultra lS
PATHWAYS
OF SPREAD OF INFECTION
Percutaneous imaging-guided treatment of abdominal fluid collections and abscesses has been considered the most prominent advance in abdominal surgery in the past decade. Intraperitoneal abscesses usually result from abdominal surgery, insufficiently treated peritonitis or conservative management of trauma. Percutaneous, non-operative management of intraperitoneal abscesses necessitates an understanding of peritoneal compartments and of pathways of spread of infection. This knowledge determines the catheter approach and indicates the intraperitoneal source of infection (Meyers, 1970, 1973). Spread of infected fluid through the peritoneal cavity is dictated by the site, volume, speed of extension, virulence of the micro-organism, peritoneal compartmentalization, pyogenic membrane formation, gravity, position of the patient and intra-abdominal pressure gradients. Diaphragmatic excursion during respiration and abdominal wall movements is responsible for a lower hydrostatic pressure in the subphrenic spaces, compared with the other peritoneal compartments. The intraperitoneal pressure gradient extending from the pelvis to the diaphragm is responsible for the ascending migration of fluid. After laparotomy, pressure gradients are temporarily compromised by the limited movements of the diaphragm and the abdominal wall. Fluid originating from the inframesocolic spaces flows to the pelvic recesses (cul-de-sac) owing to gravity, and accounts for the prevalence of residual abscesses in the pelvis after peritonitis. Pelvic fluid can overspill laterally to the paracolic gutters and ascend due to pressure gradients. The right paracolic gutter is most often filled and allows fluid to spread to the right subhepatic space. Abscess formation in the right anterior subhepatic space is unusual. The hepatorenal fossa or right posterior subhepatic space (Morison’s pouch) represents the most frequent site of infection spread from the inframesocolic space. Fluid cannot escape posteriorly from Morison’s pouch because of the coronary ligament; it spreads anteriorly and laterally BailliPre’s Clinical GastroenterologyVol. 6, No. 2, June 1992 ISBN 0-7020-162>3
273 Copyright 0 1992, by Baillitre All rights of reproduction in any form
Tindall reserved
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ET AL
around the inferior border of the liver to the right subphrenic space. Rapid formation of pyogenic membranes can limit the infection to Morison’s pouch. A peritoneal abscess in the right subphrenic space is almost always secondary to a previous contamination of Morison’s pouch, and may be associated with an abscess in that compartment. The dynamics of intraperitoneal fluid explain the prevalence of right subhepatic, Morison’s pouch and subphrenic abscesses in series with predominant appendiceal abscesses (Ochsner and De Bakey, 1938; Altemeier et al, 1973,1979). Left subphrenic abscesses are generally secondary to infected fluid originating from the stomach or spleen or following gastric or splenic surgery. Anastomotic leakage is a frequent cause of left subphrenic abscess formation. The enlarging abscess has two possible pathways of extension: beyond the midline, behind the border of the falciform ligament to the right subphrenic space; or to the pelvis along the left paracolic gutter, with possible ascent to the perihepatic spaces. Extension of infection from the left paracolic gutter to the left subphrenic space is rare when the phrenicolic ligament is intact, but can occur after surgery (Meyers, 1970). Abscess formation in the left subhepatic space is unusual and results generally from breakdown of the lesser omentum, following biliary or pyloric surgery. Lesser sac abscesses are mainly secondary to an infection of an adjacent organ, because the foramen of Winslow is rapidly closed by pyogenic membranes, which prevent contamination from the peritoneal cavity.
BACTERIOLOGY
Any micro-organism, in particular germs originating from the gastrointestinal flora, can participate in pyogenic peritoneal abscesses. Bacteriology of peritoneal abscesses was dominated in the past by Escherichia coli, Staphylococcus aureus and aerobic streptococci. Aerobic gramnegative bacteria are now being cultured with increasing frequency, especially Klebsiella spp, Enterobacter spp, Proteus spp and Pseudomonas spp. Progress in culturing techniques of anaerobes has increased the findings of gram-negative anaerobic bacilli, anaerobic cocci and clostridia, which are present in the gastrointestinal tract. In fact, almost all intraperitoneal abscesses are polymicrobial and contain a mixture of obligatory anaerobes and facultative aerobes. This association seems to be necessary to produce an abscess on an experimental basis (Weinstein et al, 1974). Although treatment of only one of the synergistic bacteria may be curative, best results are obtained when a combination of antibiotics is used for polymicrobial abscesses. Targeted systemic antibiotic therapy is the key to the success of percutaneous abscess drainage. Mycotic abscesses can occur after violation of the digestive mucosa, and are associated with predisposing factors such as central venous catheters, broad-spectrum antibiotics, parenteral alimentation, ol-adrenergic Hz-receptor blockers/antacids, malnutrition, alcoholism, steroids and chemotherapy.
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OF FLUID
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275
COLLECTIONS
Any localized intraperitoneal fluid collection suspected to be an abscess should be aspirated percutaneously for bacteriological, chemical and cytological tests. If there is no evidence of altered leucocytes and the Gram stain is negative, a drainage catheter is usually not required. When aspiration of fluid confirms pus or the presence of numerous bacteria, single or repeat aspiration or curative percutaneous catheter drainage is performed. Posttraumatic abscesses, resulting from blunt or penetrating injury, should undergo percutaneous treatment as a first choice (Styllianos et al, 1989). Sterile fluid collections such as bilomas or pseudocysts should be drained to prevent recurrence when they are large or communicating. Postoperative collections are not necessarily infected. Following hepatic resection, for instance, fluid accumulation may be seen in 40%; it is often amicrobial, and should be treated, when persistent, by short-term percutaneous drainage, to avoid later abscess formation (Pace et al, 1989). A 7-9 FG drainage catheter is generally adequate, except for recent haematomas with blood clots. Haematomas enlarge during the first few weeks, after which they liquefy, resulting in a fluid accumulation that renders their aspiration easier. Many post-traumatic intraparenchymal haematomas resolve spontaneously. If a haematoma persists, single or repeat percutaneous aspirations are generally curative. During early experience with this technique, percutaneous drainage was restricted to unique, well-defined and non-fistulized abscesses. In the early 198Os, so-called complex abscesses (multiloculated, fistulized or multiple) were considered a contraindication for percutaneous treatment; however, they are now included in many clinical trials. The absence of an anatomical window for the percutaneous approach is a contraindication for catheter abscess drainage. Sedation and correction of abnormal coagulation parameters enable most patients to be treated. Necrotized superinfected tumours should not be drained, as the results are always disappointing. Perivascular or periprosthetic abscesses and tubo-ovarian abscesses raise special problems, but are amenable to percutaneous management in highrisk patients (Matley et al, 1991). Tuberculous abscess in human immunodeficiency virus infection may also be amenable to percutaneous drainage (Bascunana et al, 1990). SELECTION
OF PATIENTS
AND PROGNOSIS
Causes of mortality secondary to treatment of abdominal abscesses are due less to technical failure than to patient risk factors, including age greater than 60 years, multiorgan failure before or after drainage, diagnostic delay, abscesses that remained undiagnosed, recurrence and specific anatomical sites (lesser sac, retroperitoneal space) (Connell et al, 1980; Fry et al, 1980; Deveney et al, 1988). The decreasing incidence of predrainage multiorgan failure is a consequence of earlier diagnosis by cross-sectional imaging. If diagnostic delay is defined as the time period from the causal factor to the time of diagnosis, a delay of 13 days was observed for peritoneal abscesses,
276
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ET AL
38 days for retroperitoneal abscesses and 48 days for pelvic abscesses (Dondelinger et al, 1987). These delays are lower than those reported in the surgical literature, which often exceed 1 month, and were defined as the time interval between the onset of clinical symptoms and diagnosis. Better understanding of the role of anaerobic bacteria in the pathogenesis of intraabdominal infection, progress in resuscitation and in antibiotic therapy are other factors responsible for improvements in the treatment of abdominal abscesses. The APACHE II score is helpful in determining the outcome of treatment of abdominal abscesses, by surgical or percutaneous drainage (Hemming et al, 1991; Levison and Zeigler, 1991). The use of ultrasonography and computerized tomography to establish the diagnosis, before single or multiple organ failure has occurred, is one of the greatest advances in abscess treatment (Fry et al, 1980; Hoogewood et al, 1986). Computerized tomography (CT) is the most sensitive and specific method for detection and localization of an abdominal abscess when used as a single test, and in cases of disagreement between different imaging modalities (Kleinhaus et al, 1982; Moir and Robins, 1982; Jasinski et al, 1987; Deveney et al, 1988; Machiedo and Suval, 1988). It is particularly helpful in patients with few symptoms (Werner et al, 1990). Ultrasonography is slightly less sensitive and specific, and rarely adds to the information obtained by CT (Doust and Thompson, 1978); however, it is useful if bedside diagnosis and drainage is required, or for access to the subphrenic and pelvic compartments. Mortality increases when initial drainage is a failure. This raises questions regarding the role of ‘temporizing’ percutaneous drainage. Temporizing percutaneous drainage is a dangerous concept, as it cannot always be defined before starting treatment. Unsuccessful temporizing is merely time lost, while the general condition of the patient deteriorates rapidly. Certain patients, even in poor general condition, should therefore be operated upon, when total cure can be expected by a single operation (Werner et al, 1990). The types of abscess in which drainage is often unsuccessful include infected haematoma, diffuse abscess and pancreatitis (Berger et al, 1989). Fistulized abscesses detected by delayed contrast sinograms usually do not increase mortality, but lead to a change in catheter management or to delayed surgery, when closure of the fistula is not obtained (Berger et al, 1989). Finally, errors in drainage technique and catheter management may account for the vast majority of failures of percutaneous drainage, which raises the problem of education and training in interventional imagingguided procedures (Lang et al, 1986). TECHNICAL
CONSIDERATIONS
Percutaneous aspiration and drainage are mainly performed under ultrasonographic or CT control. When percutaneous treatment of an intraperitoneal fluid collection is considered, special attention should be given to the most direct access to the fluid collection. Previous surgical reports have emphasized the significant difference in morbidity and mortality when an
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extraperitoneal approach was used compared with a transperitoneal approach. Large laparotomy carries a higher risk for infectious spread to previously uncontaminated compartments. Therefore, the percutaneous access route should be defined on cross-sectional images in such a way that approach remains extraperitoneal with direct puncture of the peritoneal abscess. A minimal number of peritoneal compartments should be crossed by the catheter, and large vessels, nerves and solid organs should be avoided. In the authors’ experience, CT imaging enabled percutaneous puncture solely of the peritoneal compartment that contained the abscess in 91% of patients. Nine per cent of abscesses were reached by crossing another compartment, not previously involved in the spontaneous spread of the infectious process. Secondary infection of that compartment did not occur (Dondelinger et al, 1987). Although no complication was observed when solid organs or bowel were penetrated by a 7-FG drainage catheter, every effort should be made to achieve an ideal anatomical approach to the abscess. Failure to define an appropriate percutaneous route to a peritoneal abscess is rare (less than 1%). Most interloop abscesses can be punctured with a safe percutaneous catheter insertion, sometimes only after changing the position of the patient to allow a convenient percutaneous approach, by displacing adjacent mobile structures. Ultrasonography is optimal for imaging of the diaphragm and enables the radiologist to plan a subdiaphragmatic access route when subphrenic abscesses are drained. (Gerzof, 1981; Mueller et al, 1986). The lateral extent of right subphrenic abscesses caudal to the lateral pleural sulcus allows puncture of the collection with CT control and placement of the catheter in the upper portion of the subphrenic space over a guide wire with fluoroscopic control. In specific cases, a ‘triangulation’ approach (Gerzof, 1981a; vansonnenberg et al, 1981) can be used. There is a tendency to prefer a one-step aspiration to a more complex catheter insertion with the Seldinger technique when ultrasound is used as a guiding modality; however, this appears to be associated with a higher rate of recurrences (Civardi et al, 1990). The tip of the catheter should be placed in the most dependent part of the cavity or in a position where maximum negative pressure is expected. A Teflon sheathed needle or trocar (l&gauge or 5FG) is preferred to a 22-gauge needle for diagnostic fluid aspiration, as the needle must be large enough to allow aspiration of viscous pus. The drainage catheter can be inserted with the Seldinger technique over a guide wire through the diagnostic needle, avoiding another puncture. The authors prefer the trocar technique, with a 9-14FG pigtail or straight catheter, whenever a safe percutaneous access is possible. The trocar technique reduces percutaneous manipulation compared with the Seldinger technique and avoids peritoneal leakage of pus. The single-step trocar technique removes the need for repeated passage of dilators over the guide wire along the drainage track with the potential risk of spilling pus, which may lead to infection of other compartments and the subcutaneous tissue. Dilation of the track may, however, be necessary when the abscess has a strong capsule. The calibre of the drainage catheter must be adapted to the viscosity of the drained pus. Surgeons often advocate the use of large-bore catheters, whereas radiologists may refrain from using these catheters, claiming that
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larger catheters do not improve the results of percutaneous drainage (Gobien et al, 1985). Subcutaneous abscesses can occur at the entry site of the catheter following a difficult insertion and usually do not resolve until the drainage material has been removed. Suturing the catheter to the skin is mandatory to prevent inadvertent displacement. Self-retaining catheter devices should not be used. Catheter patency is maintained by four to six daily gentle injections of 5 ml saline through the catheter. Irrigation of the abscess cavity is not recommended as it is associated with septic complications and prolongs the duration of drainage (Dondelinger et al, 1987). The efficacy of antibiotics or mucolytic agents injected in the abscess has not been proved. Gentle suction can be applied to the drainage catheter, but gravity-dependent drainage is usually sufficient. Some patients can be discharged from the hospital with the drainage catheter in place, thus reducing costs (Rifkin et al, 1985). Efficient percutaneous drainage leads to rapid improvement of the patient’s general condition, decrease of fever with temperature normalizing in 4 days, and significant improvement in local pain and tenderness. When there is no clinical change 48-72 hours after a percutaneous drainage catheter has been correctly placed, treatment is probably inadequate. Contrast sinograms or cross-sectional imaging of the drained abscess cavity are performed when the clinical evolution is not favourable, with persistent fever, bacteraemia and leucocytosis, or undiminished or increased drainage output. Contrast medium should not be injected with a pressure higher than the hepatic venous pressure to avoid haematogenous spread of infection and pericatheter spilling of pus which can lead to peritonitis. The drainage is stopped and the catheter is withdrawn 2 days after decrease of drainage to 5-lOm1, defervescence and normalization of leucocytosis. RESULTS Many non-randomized studies have compared the results of percutaneous and surgical drainage (Table 1). Considerable variations among studies are observed, but the techniques are equivalent in terms of initial drainage success, morbidity, mortality and length of hospital stay. Several reports suggest that percutaneous drainage may be superior for specific sites, such as subphrenic abscesses (Johnson et al, 1981; Van Gansbeke et al, 1989). Some anatomic sites are associated with a high mortality risk (Fry et al, 1980). Mortality from percutaneous drainage appears to be lower than following surgical drainage, but results vary with selection of patients. The optimal indication is a well-defined, single, non-fistulized primary hepatic or renal abscess; the worst case is a deeply located, multiloculated and fistulized abscess in an immunocompromised patient. Experience from the literature and results from a personal prospective series indicate that complex abscesses can be drained percutaneously with good results, but they require more attention during treatment (vansonnenberg et al, 1984; Dondelinger et al, 1987). In the latter study, percutaneous drainage was performed in all abdominal abscesses diagnosed. This series included 50%
PERCUTANEOUS Table
1.
MANAGEMENT
279
COLLECTIONS
Results of surgical and percutaneous treatment of peritoneal abscess.
Author Johnson et al (1981) Aeder et al (1983) Brolin et al (1984) Glass and Cohn (1984) Olak (1986) Moessner (1986) Lurie et al (1987) Deveney et al (1988) Total
OF FLUID
Drainage
Patients n
PD SD PD SD PD SD PD SD PD SD PD SD PD SD PD SD
27 43 10 31 24 24 15 44 27 27 21 25 29 60 29 37
PD SD
182 291
Success Complications % % 89 70 69 92 87 47 88 70 85 75 64 80 81 72 78 78.5 76.5
4 16 15 56 8 21 6 23 41 30 60 -
Mortality % 11 21 23 37 12
Drainage duration (days) 17 29 12 21
-
-
-
11 7 13 16 17 17 21 22
31 16 27 34 36 33
10 22
13 16.5
30 33
PD, percutaneous drainage; SD, surgical drainage.
of multiple or complex (fistulized or multilocular) abscesses. Percutaneous drainage was successful in 88% of single, unilocular abscesses and in 63% of complex abscesses. The mortality rate was 33% in patients undergoing operations for failure of percutaneous drainage. The overall success rate was 70% (Dondelinger et al, 1987). These results are consistent with other reports (Gerzof et al, 1985; Lameris et al, 1987). Multiple or complex abscesses can be treated with a temporizing drainage in 11% of cases of peritoneal abscess and in 36% of retroperitoneal abscesses (vansonnenberg et al, 1984b). Depending on the cause of the abscess, secondary surgical treatment may become necessary (i.e. repair of an anastomotic leak). Percutaneous abscess drainage successfully replaces the first operation of a two-step surgical procedure, when hollow viscus perforation is the cause of abscess (Flancbaum et al, 1990). Another interventional treatment can become necessary: diversion of a high-output enteric fistula, biliary or urinary drainage. Successful treatment of abscesses caused by biliary, small bowel and gastric fistulae, as well as anastomotic leaks, has been reported and in these situations percutaneous drainage is a reasonable therapy of first choice in selected patients (Van Waes et al, 1983; Gerzof et al, 1985). Recurrent or persistent abscesses are associated with a high surgical mortality (Altemeier et al, 1973; Fry et al, 1980) because of the necessity of repeat laparotomy and a potential decrease of immunity due to prolonged sepsis. A mortality rate of 50% was reported after surgical treatment of recurrent abscesses. In the authors’ experience, 20% of patients with recurrent abdominal abscess died after a second percutaneous drainage. Abscesses that persist after a failed percutaneous attempt should be
280
R. F. DONDELINGER
ET AL
operated upon rapidly before sepsis becomes generalized, as surgical debridement may in such cases be the only way to cure the patient. LIVER
ABSCESS
The incidence of liver abscess is unknown. The number of cases reported in the recent radiological literature is 1.8 times higher than the number reported per year in the surgical literature. The sensitivity of detection has improved with the increasingly widespread use of ultrasonography and CT since the mid-1970s (Dondelinger et al, 1990). Pyogenic liver abscesses are now diagnosed easily, even when small, although the time interval from the causal event to diagnosis and treatment is uncertain in many cases and can exceed several years, particularly after liver trauma. The sensitivity of ultrasound and CT imaging in the detection of hepatic abscesses is 76% and 85% respectively (Jasinski et al, 1987). Pyogenic abscesses are of biliary, portal, arterial or hepatic origin, or they are due to spread from infection adjacent to the liver. The aetiologic factors have changed over the years: in early surgical reports, appendicitis was responsible for one-third of liver abscesses. In radiological reports (McFadzean et al, 1953; Berger and Osborne, 1982; Kuligowska et al, 1982; Dahnert et al, 1983; Bernardino et al, 1984; Johnson et al, 1985; Gerzof et al, 1985; McCorkell and Niles, 1985; Attar et al, 1986; Bertel et al, 1986; Gyorffy et al, 1987; Sperling et al, 1987; Farges et al, 1988; Pelissier and Ranieri, 1989; Dondelinger et al, 1990) abdominal and biliary surgery account for 27-55% of hepatic abscesses, but in 7-30% no precise cause of liver abscess could be found. It is stressed that bacteria cultured from blood are not necessarily confirmed from pus aspirated from the liver abscess. No specific bacteriologic pattern of hepatic abscess has emerged, but anaerobes are encountered more often than in abscesses in general. Hepatic abscesses are unimicrobial in 27-78%, polymicrobial in 7-47% and amicrobial in O-27% (Dondelinger et al, 1990). Amicrobial abscesses may occur more frequently following systematic antibiotic therapy. During the preantibiotic era, unrecognized pyogenic liver abscesses were associated with a mortality of almost 100%. Surgical management reduced overall mortality to 50-70% over the years. Mortality resulting from surgical treatment was reduced to O-25% for a single abscess when adequate drainage was established, and to 20-40% or higher, when multiple abscesses were present (Bertel et al, 1986; Sperling et al, 1987; Farges et al, 1988). The main reasons for better surgical prognosis of hepatic abscess (as for other abscess locations) were early recognition and refinements in antibiotic therapy and supportive care. Since the first report (McFadzean et al, 1953) demonstrating closed percutaneous management of liver abscess as a valuable alternative to surgical drainage, many case reports of percutaneous aspiration and drainage of liver abscess with ultrasonographic or CT guidance have been published, and have recently been reviewed (Dondelinger et al, 1990). An analysis of 252 patients from 15 published reports showed a male/female ratio of 2.13. The predominance of male patients was found in the earlier surgical reports but not in later
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281
surgical studies because of the growing frequency of biliary disease (responsible for liver abscess) which is more common in females. The mean age of patients overall was 43.6 years, which is lower than in surgical reports. The right lobe of the liver was affected in 80% of patients, the left lobe in 16% of patients and both lobes in 4% of patients. Single pyogenic abscesses were treated in 76% of patients and multiple abscesses in 24%. The small number of patients with multiple abscesses probably reflects the initial restriction of percutaneous drainage to cases of solitary abscess. In the surgical literature, patients with multiple abscesses almost equal the number of patients with solitary abscess (Farges et al, 1988). The average duration of drainage of liver abscesses was 19.5 days. A single aspiration followed by antibiotic therapy was sufficient in some patients; however, several aspirations were required when the volume was large. Initial unsuccessful aspiration was usually followed by percutaneous drainage. Ultrasound was usually the preferred method of guidance for percutaneous treatment. When CT was used as the guidance modality percutaneous catheter drainage was achieved in 87% of patients. When ultrasound and CT were used together, all patients were drained. When ultrasound was used as the guidance modality, an overall success rate of 86% was achieved, when CT was used, the success rate was 82%; and when both modalities were used, a success rate of 55% was observed-66% when the pessimistic study of McCorkell and Niles (1985) was excluded. These figures reflect the preference for ultrasonography for percutaneous aspiration in less critical patients. Successful percutaneous treatment was achieved in 90% of cases of solitary hepatic abscess and in 74% of multiple abscesses, the overall success rate being 77%. These figures are consistent with data from the surgical literature. Multiple liver abscess seems to be associated with critical underlying disease. The ratio of primary abscesses to secondary abscesses was 5.3. Primary liver abscesses, which develop in ‘normal’ liver parenchyma, were successfully treated in 81%. Secondary liver abscesses were defined as superinfection of a pre-existing circumscribed hepatic lesion. They were almost unknown in the early surgical reports and represent 16% of abscesses treated radiologically. Secondary liver abscesses include superinfection of primary and secondary malignant liver tumours, lymphoma and leukaemic infiltration, hepatic cysts, polycystic disease in renal transplant patients, hydatid cyst, haematoma, contusion, necrosis following arterial embolization or chemotherapy. Patients with a secondary hepatic abscess are often referred for percutaneous treatment when they are critically ill and have become poor surgical candidates. In these patients, infection can only be treated percutaneously with large-bore catheters which are able to drain necrotic debris. Prolonged percutaneous drainage is expected and accounts for long hospital stays. When surgery is able to cure the infected hepatic lesion, these patients should be operated on without previous percutaneous drainage. Success of percutaneous drainage of secondary hepatic abscesses is 60%. No randomized series comparing percutaneous and surgical drainage of pyogenic liver abscess is available in the literature. Two radiologcal studies are prospective, as all patients with liver abscess had radiological treatment as a first
2. Results
of surgical
86(n
Sperling 197+1986et al (1987)
= 29)
83 (n = 23)
(n = 22)
90.5 (n = 21)
Surgery
Success
and percutaneous
Bertel et al (1986) 1971-1984
1978-1986
Farges et al (1988) 1966-1977 (n = 24)
Table
treatment
74(n
81(n = 27)
= 16)
72 (n = 18)
Percutaneous treatment
(%)
14
17
0
24
Surgery
of pyogenic
0
13
0
Percutaneous treatment
(%)
abscess.
Death
liver
47
48
29
Surgery
(%)
33
69
20
Percutaneous treatment
Complications
26days
Equal
Surgery
Hospital
46 days
Percutaneous treatment
stay
P WI
PERCUTANEOUS
MANAGEMENT
OF FLUID
COLLECTIONS
283
choice during the time of study; an overall success rate of 84% and a mortality rate of 9% were reported (Gerzof et al, 1985; Dondelinger et al, 1990). Comparison of the most optimistic report (McFadzean et al, 1953) and the most pessimistic report (McCorkell and Niles, 1985) shows the influence of patient selection on outcome. The mean age of the patients in the series of McFadzean et al was 18 years and no one had a debilitating underlying disease; the repeat aspiration success rate was 100%. On the other hand, in the series of McCorkell and Niles, 2 patients had multiple abscesses, 3 had infected ruptured hydatid cyst, 1 had a hepatoma and 1 had acute leukaemia. The mean age was 37 years; overall success rate was 10% and mortality rate was 50%. In three series, surgical results are compared with percutaneous drainage (Bertel et al, 1986; Sperling et al, 1987; Farges et al, 1988) (Table 2). Similar results were obtained with both methods but the advantage of percutaneous treatment was obvious in the postoperative period, in complex situations, in high-risk patients, when the patients could benefit from a temporizing drainage, provided the general condition of the patient improved. Percutaneous drainage could be established with equal ease in either lobe of the liver. The need for resection of an abscess located in the left lobe was obviated. Further accumulation of fluid in the abscess cavity after initial successful aspiration or drainage was not an indication for surgical revision. The reaccumulated fluid is often amicrobial and a second aspiration or a mini-drainage of several days should be performed. Some cavities, such as surgically treated hydatid cysts, do not collapse and are prone to fluid reaccumulation. Biliary fistulae, which are frequently observed in secondary liver abscesses following trauma, will generally close after prolonged drainage, provided there is no persistent biliary obstruction. Failure of percutaneous treatment of liver abscess may be caused by many factors. Technical errors leading to interruption or failure of percutaneous drainage are rare. Septic contamination of the pleura and peritoneum can occur during percutaneous drainage, but patients with perihepatic ascites are at particular risk for peritonitis. The overall death rate was 6.2%, which is similar to surgical results. Half of the patients who died had subsequent surgery. They were cancer patients or had infected echinococcal cysts. Considering patients in series with fewer than 10 patients per series percutaneously treated and including amoebic abscesses, a success rate of 93% and a mortality rate of 3% was found, which reflects patient and abscess selection. Identical figures from the literature are found in another report (Gerzof et al, 1985). It is advocated that patients under 40 years old, who are not debilitated, are not critically ill and who are without evident causal disease should undergo simple aspiration and medical treatment of their liver abscess. Also patients with multiple abscesses smaller than 2cm in diameter and miliary abscesses can benefit from this treatment. Older patients with large abscesses and with another persistent disease should be drained (Figure 1). Subcapsular abscesses are often secondary to a preexisting collection; they will not be reached by antibiotics and should also be drained. Abscesses resulting from biliary obstruction and secondary abscesses should be drained. Failed percutaneous drainage should lead to surgery, before sepsis becomes generalized. Surgery should not be delayed
284
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F. DONDELINGER
ET AL
for infected hepatic tumours, when an operation can cure the patient, for tre atment of a source of abdominal infection, when an abscess has ruptu red intl o the peritoneal cavity or when peritonitis has occurred due to inadequ Pe’xutaneous manipulation.
(4
PERCUTANEOUS
MANAGEMENT
OF FLUID
COLLECTIONS
285
(4 1. A 73-year-old male underwent cholecystectomy and choledocho-duoI denalanastomosis for bile stones. Two weeks after surgery, he developed sepsis and cholestasas. (4 Abdominal CT showed a septated 8 cm abscess in the right lobe of the liver. (b) Percuta mt:ous abscess drainage was achieved with a 12-FG vansonnenberg sump catheter under ultra lS
