J Clin Ultrasound 20:375380, July/August 1992 0 1992 by John Wiley & Sons, Inc. CCC 0091-2751/92/060375-06$04.00
Ultrasonic Detection of Viscera Slide as an Indicator of Abdominal Wall Adhesions Issei Kodama, MD, Laurie A. Loiacono, MD, Bernard Sigel, MD, Junji Machi, MD, PhD, Robert M. Golub, MD, Richard E. Parsons, MD, Jeffery Justin, Howard A. Zaren, MD, and Ajit K. Sachdeva, MD
Abstract: Real-time ultrasonography can detect the movement of viscera immediately deep to the abdominal wall. This motion of abdominal contents is called viscera slide, and is produced by the force of respiratory motion (spontaneous viscera slide) or by manual ballottement of the abdomen (induced viscera slide). Viscera slide was observed in 18 “normal” subjects (no history of previous abdominal surgery or peritonitis) and in 24 subjects a t “ r i s k for abdominal wall adhesions because of previous abdominal operations or past history of peritonitis. In 14 of the 24 “risk” group subjects, spontaneous and induced viscera slide was restricted to excursions of less than 1 cm (58.3%).Operations were performed on 18 patients, which confirmed the fact that restriction of ultrasonically detected viscera slide identified abdominal wall adhesions in all cases, but no adhesions were found in patients with normal viscera slide. This ultrasonic finding of restricted viscera slide may be useful in the preoperative discovery and localization of abdominal wall adhesions prior to laparoscopy or laparotomy. Indexing Words: Ultrasound imaging Abdominal wall adhesions * Intestinal adhesions * Adhesions Viscera slide
-
Real-time ultrasonography can detect the movement of viscera during ultrasound examination of abdominal organs and structures. By scrutinizing the junction between the deepest layer of the abdominal wall and the more mobile abdominal contents, the abdominal viscera can be observed to slide in relation to the abdominal wall. This sliding is a result of forces applied by respiratory excursions or by manual ballottement of the abdominal wall. We refer to this motion of abdominal contents immediately deep to the abdominal wall as viscera slide. Spontaneous viscera slide is more evident with longitudinal scanning of the abdomen because respiration-induced movement is greater in the longitudinal axis than in the transverse axis. Viscera slide induced by manual ballottement is dependent upon the compressive force being applied along the plane being scanned. The occurrence of ultrasonically detected vis-
-
cera slide suggests a possible simple approach to the identification of abdominal wall adhesions prior to laparoscopy or open abdominal surgery. With this point in mind, we conducted a preliminary study in two human subject groups: (1)subjects who were likely to be free of adhesions, and (2) subjects with a greater likelihood of abdominal wall adhesions as a result of previous abdominal operations or past history of peritonitis. This study indicates that ultrasonically detected viscera slide during abdominal scanning is normally present in subjects without previous abdominal surgery, but may be significantly restricted beneath the healed scars of subjects who have had a previous operation or past history of peritonitis. These results suggest that ultrasonically detected viscera slide may be useful for detecting the presence or absence of abdominal wall adhesions. METHODS
From the The Medical College of Pennsylvania, Philadelphia, Pennsylvania. For reprints contact Bernard Sigel, MD, The Medical College of Pennsylvania, 3300 Henry Avenue, Philadelphia, Pennsylvania 19129.
The ultrasound examination was performed with the subject in the supine position. A 5-MHz or 7.5-MHz real-time ultrasound imaging system 375
376
KODAMA ET AL.
FIGURE 1. Two sonograms (A, B) of the abdominal wall at different phases of normal respiration during longitudinal scanning. A normal respiratory excursion of about 3 cm is evident in the movement of the focal area (demarcated by the bracket) in reference t o the metal marker (open arrow) on the skin surface. The metal marker is associated with an acoustic shadow. Solid arrows indicate the junction of the abdominal wall and the abdominal cavity.
was used. Our principal interest was to discover restricted viscera slide suggesting the presence of adhesions between the abdominal structures and the abdominal wall. We usually examined selected sites of interest on the basis of two considerations: first, we scanned beneath healed ab-
dominal scars; second, we scanned sites where surgical incisions were planned. For example, in laparoscopic surgery, the first trocar is often inserted at or just below the umbilicus. In these instances, we evaluated the viscera slide in the umbilical region. Viscera slide was identified in
FIGURE 2. Two sonograms (A, B) of the abdominal wall at different phases of normal respiration over a healed surgical incision during longitudinal scanning. Restricted viscera slide of less than 1 c m is evident i n the movement of the focal area (demarcated by the bracket) i n reference t o a metal marker (open arrow) on the skin surface. The solid arrows indicate the junction of the abdominal wall and the abdominal cavity. JOURNAL OF CLINICAL ULTRASOUND
DETECTION OF VISCERA SLIDE
the real-time ultrasound image by tracking a persistent cluster of structures of varying echogenicity that moved horizontally beneath the more stationary abdominal wall. This persistent cluster was used as a focal area for recognizing viscera slide. The examination began by observing the motion of structures immediately deep to the abdominal wall. This helped us to identify the deep layer of the abdominal wall. Next, attention was given to identifying a moving focal area beneath the abdominal wall whose shape and gray-scale characteristics persisted as the focal area moved through several respiratory excursions. This provided a tracking marker that was used to estimate the distance traversed by the abdominal viscera at the abdominal wall. We began the examination with longitudinal scanning to observe spontaneous viscera slide (producedby respiratory motion) at selected sites of interest. Normal respiratory movements usually produced viscera slide excursions of 1 cm to 2 cm during longitudinal scanning (Figure 1). If the viscera slide appeared to be diminished, the examiner was attentive to possible causes of inadequate respiratory movement, such as impaired respiratory excursions (e.g., chronic obstructive pulmonary disease) or a patient who was not cooperating (e.g., impaired consciousness). When there was any question about the effectiveness of respiratory motion, the patient was asked to take a few deep breaths. During exaggerated respiratory excursions, viscera slide was more pronounced. With exaggerated respirations, longitudinal scanning of viscera slide usually revealed excursions greater than 3 cm. Finally, diminished viscera slide due to inadequate respiratory movement was highly suggested by reduced viscera slide in all areas being examined, whether beneath a scarred or unscarred abdominal wall. Induced viscera slide by manual ballottement of the abdomen by the examiner was performed during all transverse scanning examinations and during longitudinal scanning when there was any question about the adequacy of respiratory movement. Manual compression was applied gently with no more vigor than is used in the routine physical examination of the abdomen. When the manual force ordinarily used in a physical examination was applied along the scan path, viscera slide was observed. During longitudinal scanning, manual compression was applied either superiorly or inferiorly to the transducer in contact with the abdominal wall. During transverse scanning, manual compresVOL. 20, NO. 6, JULYiAUGUST 1992
377
sion was applied at either lateral side of the transducer. The distance traversed by the induced viscera slide was usually less than the distance traversed by spontaneous viscera slide. Induced viscera slide was usually greater than 1 em. When there was a question about impairment of induced viscera slide at a particular location, the extent of the motion excursions at several sites were compared to determine whether the induced viscera slide was restricted locally or generally. We defined restricted viscera slide as movement of less than 1 cm during both longitudinal and transverse scanning (Figure 2). The presence of viscera slide movement was always assessed on the basis of the relationship of the abdominal content t o the abdominal wall. This was a key factor, particularly in viscera slide induced by manual compression. During manual compression of a scarred abdomen with restricted viscera slide, the abdominal wall and abdominal content may be made to move together beneath the transducer. Such bulk motion can be mistaken for viscera slide unless viscera motion is carefully distinguished from abdominal wall motion. RESULTS
Ultrasonic detection of viscera slide has been performed in 42 human subjects (Table 1).The subjects were considered in terms of their potential for having abdominal wall adhesions. One group included 18 subjects who had not undergone previous abdominal surgery and did not have a past history suggesting peritonitis. These subjects, who were not considered at risk for adhesions, were called the “normal” group. The second group included 24 subjects who had previous abdominal operations (23 subjects) or a past history of peritonitis (1 subject). These subjects were considered potentially at risk for adhesions and were called the “risk” group. During longitudinal scanning of members of the normal group, all subjects exhibited spontaneous viscera slide (resulting from respiratory movement) of 1cm or greater during regular respiration and greater than 2.5 cm during exaggerated respiration. Induced viscera slide (resulting from the examiner’s manual compression) was usually between 1cm and 2 cm, but rarely more than 2 cm in the normal group. The extent of induced viscera slide is related to the force of manual compression. The less extensive viscera slide produced by manual compression (as opposed to
KODAMA ET AL.
378
TABLE 1 All Subjects Examined for Viscera Slide Spontaneous Viscera Slide
Induced Viscera Slide
Type of Subject
Number of Subjects
Normal
Restricted
Normal
Restricted
Normal
18 24
18 10
-
18
-
14
14
10
Risk
spontaneous respiratory motion) is probably due to limitations on the acceptable vigor of the compression maneuver, which should be no greater than the force applied in the routine physical examination of the abdomen. Restricted viscera slide was observed in 14 of 24 subjects in the risk group (58.3%).Restricted viscera slide, when found, was beneath a surgical scar in all except 1subject. Restricted viscera slide was more definitively identified in the observations of spontaneous viscera slide on longitudinal scanning. Where longitudinally scanned spontaneous viscera slide was less than 1 cm (after exaggerated respiration), manual compression during both the longitudinal and transverse scans was performed. If spontaneous viscera slide during longitudinal scanning and induced viscera slide during both longitudinal and transverse scanning were less than 1 cm, the viscera slide was considered to be restricted. Abdominal operations within a week of the ultrasound examination were performed in 18 subjects (Table 2). Five of these were from the normal group and did not reveal adhesions. Of the 13 risk group subjects, 6 exhibited normal viscera slide and showed no adhesions at operation. Seven of the 13 risk group subjects exhibited restriction of viscera slide. In 3 of these 7 subjects, only spontaneous viscera slide was restricted. All 7 subjects were found to have adhesions at surgery. In the 3 subjects in whom spontaneous viscera slide was restricted but induced viscera slide was normal, operation revealed either a single dense adhesion or thin filmy adhesions at the site of restricted spontaneous viscera slide. These findings suggest that restriction of sponta-
Percentage Restricted %
0.0
58.3
neous viscera slide may be a more sensitive indicator of adhesions and that a disparity of findings may result from less extensive adhesions. Table 3 presents more detailed information about the 13 risk subjects in whom adhesions were confirmed or excluded at operation. The 6 subjects from the risk group with normal visceral slide and no adhesions at operation had shorter scar lengths (mean = 7.2 cm) than subjects with proven adhesions. The group of 7 risk subjects with operative confirmation of adhesions had generally longer incisions (mean = 16.5 cm) from previous surgical procedures. In addition, those same risk subjects had undergone the more extensive previous operative procedures. Adhesions were localized to the area directly beneath previous operative scars in 5 of the 7 subjects with operative confirmation. Thus, restricted viscera slide at the umbilical region was usually associated with scars that were in proximity to the umbilicus. One patient with a history of pelvic inflammatory disease had diffuse adhesive disease throughout the left and right lower quadrants. In 1 patient who had previously undergone a hysterectomy from a midline incision, the adhesions were found to be localized away from the scar site, in the right lower quadrant. In summary, normal and abnormal viscera slide can be distinctly defined by simple measurement of excursion distances (Table 4). In Table 4, the normal group consists of the 18 normal subjects and the 6 risk subjects who at operation were found not to have adhesions. The abnormal group in Table 4 are the 7 risk patients who revealed adhesions at surgery. Overall, ultrasonically observed viscera slide has been 100% cor-
TABLE 2 Ultrasound Examination Confirmed by Laparoscopy or Laparotomy Type of Subject
Number of Subjects
Normal Risk
13
5
Ultrasound Examination Normal viscera slide Normal viscera slide in 6 Restricted spontaneous and induced viscera slide in 4 Restricted spontaneous and normal induced viscera slide in 3
Operative Findings No adhesions No adhesions Adhesion beneath scar Single or filmy adhesions at the site of restricted viscera slide JOURNAL OF CLINICAL ULTRASOUND
DETECTION OF VISCERA SLIDE
379
TABLE 3 Risk Group Information Viscera Slide Subject No
Normal
1 2
Location
Length
+
Low midline Low midline and low right paramedian
cm 6 12 9
-
-
+
4 5 6
+
7
+ +
8
Restricted
+
3
+
9 10 11 12
+
13
+
Abdominal Wall Scar
+ + + +
Type of Previous Abdominal Operation Hysterectomy Hysterectomy and appendectomy
Beneath scar Beneath midline scar
-
lnfraumbilical lnfraumbilical Low midline
2 10
lnfraumbilical Upper midline Long midline Left paramedian Low midline Long midline
2 12 21 20 11 30
Umbilical hernia repair Laparoscopic tuba1 ligation Hysterectomy and umbilical hernia repair Laparoscopic exploration Exploratory laparotomy Exploratory laparotomy Unknown Cesarian section Aortobifemoral bypass
Low midline
12
Hysterectomy
4
Site of Adhesion
Right and left lower quadrants No adhesions No adhesions Right lower quadrant
No adhesions No adhesions Beneath scar Beneath scar No adhesions Beneath scar and right lower quadrant No adhesions
”This patient has a history of pelvic inflammatory disease.
rect to date in identifying the presence or absence of abdominal wall adhesions. DISCUSSION
This article describes how an ultrasonic finding may be useful in discovering and mapping abdominal wall adhesions. Restricted viscera slide occurred in a high proportion of subjects with previous operations, and it was not evident in subjects without previous abdominal surgery or a history of peritonitis. Further work will be needed to determine just how useful this finding is in detecting adhesions. Such work should focus on the recent heightened interest in the use of laparoscopic surgery by providing better information for the selection of patients for operative procedures and for more precise guidance during placement of laparoscopic instruments. This technique could also be used in identifying and mapping abdominal wall adhesions prior to laparotomy or other invasive abdominal procedures (for example, peritoneal dialysis or lavage). The development of a simple method with the potential t o detect abdominal wall adhesions preoperatively was prompted by an increased recent interest in laparoscopic surgery, particularly therapeutic laparoscopy, such as laparoscopic cholecystectomy. During laparoscopy, the first trocar is inserted “blindly,” but all subsequent trocars are introduced under direct visualization through the portal provided by the initial trocar. The adherence of abdominal viscera and structures (e.g., omentum) to the site of placement of VOL. 20, NO. 6, JULY/AUGUST 1992
the first trocar could result in inadvertent injury to blood vessels or viscera with subsequent complications, such as hemorrhage, perforated viscus, and perit~nitis.’-~ In addition to minimizing the risk of these complications, the preoperative localization of adhesions allows the surgeon to plan the entry portal to avoid the technical difficulties of working in an area of adhesions, therefore reducing potential extended dissections and prolonged operating times. For these reasons, a preoperative imaging technique that could indicate the presence and location of abdominal wall adhesions in patients with previous operations would be very useful. Insertion of saline or gas through a needle is usually performed prior to introduction of the first trocar. However, the apparent easy passage of fluid or gas does not provide complete protection from accidents, and complications have been r e ~ 0 r t e d . lThese ~ ~ limitations have prompted the search for ultrasonic methods to detect adhesions. In 1987, Marin and associates2 reported on an TABLE 4 Normal and Abnormal SpontaneousViscera Slide Distances Group
N
Normal Abnormal
24 7
Normal Respirationsa
Exaggerated Respirationsa
cm 1.6 0.4
3.5 zk 0.9
0.4 + 0.3
0.8 ? 0.2
*
“Data presented are mean in cm +SD.
cm
380
KODAMA ET AL.
ultrasonic technique to detect abdominal adhesions prior to laparoscopy. Their approach was to repeat the ultrasound examination after pneumoperitoneum had been established. Ultrasound examination of an area free of adhesions was “characterized by a large conical shadow, inside which there are dense horizontal hyperechogenic lines due perhaps to the reflection of echoes of the wall layers. When adhesions are present, however, the image is amorphous and irregular, caused by more or less reflective or coarse echoes.” These authors found the postpneumoperitoneum ultrasound examination useful in guiding trocar placement in patients with abdominal adhesions. The technique that we describe has the advantage of being completely noninvasive. The presence and location of adhesions is determined not only prior to laparotomy or laparoscopy, but prior to insertion of a needle to inject saline or gas. For this reason, ultrasonic detection of viscera slide may be used conveniently prior to any surgical maneuver. Such examinations could be performed in any ambulatory ultrasound examination setting. Furthermore, ultrasonic detection of viscera slide to discover and map abdominal wall adhesions could be achieved at the time of other ultrasound examinations to diagnose conditions that may be treated by laparotomy or
laparoscopy. For example, the ultrasound examination that is positive for gallbladder calculi could be extended to include a search for adhesions if such abnormalities are suspected on the basis of previous operations or a history of peritonitis. Thus, a patient with biliary calculi, who is likely to require an operation and who is also at risk for abdominal wall adhesions, may only need to make a single trip to a diagnostic ultrasound facility. In summary, these data indicate that the proposed procedure for detecting abdominal wall adhesions may be clinically significant; however, further experience is needed to verify these early findings. REFERENCES
1. Dagnini G Clinical Luparoscopy. Padova, Piccin Editore, 1978. 2. Kane MG, Krejs GJ: Complications of diagnostic laparoscopy in Dallas: A 7-year prospective study. Gastrointest Endosc 30:237, 1984. 3. Marin G, Bergama S, Miola E, Caldironi MW, Dagnini G Prelaparoscopic echography used to detect abdominal adhesions. Endoscopy 19:147, 1987. 4. Penfield AJ: How to prevent complications of open laparoscopy. J Reprod Med 30:660, 1985. 5. PlePner I, Berndt H, Gutz H-J: Laparoscopy following abdominal operations. Endoscopy 10:187,1978.
JOURNAL OF CLINICAL ULTRASOUND
Ultrasonic Detection of Viscera Slide as an Indicator of Abdominal Wall Adhesions Issei Kodama, MD, Laurie A. Loiacono, MD, Bernard Sigel, MD, Junji Machi, MD, PhD, Robert M. Golub, MD, Richard E. Parsons, MD, Jeffery Justin, Howard A. Zaren, MD, and Ajit K. Sachdeva, MD
Abstract: Real-time ultrasonography can detect the movement of viscera immediately deep to the abdominal wall. This motion of abdominal contents is called viscera slide, and is produced by the force of respiratory motion (spontaneous viscera slide) or by manual ballottement of the abdomen (induced viscera slide). Viscera slide was observed in 18 “normal” subjects (no history of previous abdominal surgery or peritonitis) and in 24 subjects a t “ r i s k for abdominal wall adhesions because of previous abdominal operations or past history of peritonitis. In 14 of the 24 “risk” group subjects, spontaneous and induced viscera slide was restricted to excursions of less than 1 cm (58.3%).Operations were performed on 18 patients, which confirmed the fact that restriction of ultrasonically detected viscera slide identified abdominal wall adhesions in all cases, but no adhesions were found in patients with normal viscera slide. This ultrasonic finding of restricted viscera slide may be useful in the preoperative discovery and localization of abdominal wall adhesions prior to laparoscopy or laparotomy. Indexing Words: Ultrasound imaging Abdominal wall adhesions * Intestinal adhesions * Adhesions Viscera slide
-
Real-time ultrasonography can detect the movement of viscera during ultrasound examination of abdominal organs and structures. By scrutinizing the junction between the deepest layer of the abdominal wall and the more mobile abdominal contents, the abdominal viscera can be observed to slide in relation to the abdominal wall. This sliding is a result of forces applied by respiratory excursions or by manual ballottement of the abdominal wall. We refer to this motion of abdominal contents immediately deep to the abdominal wall as viscera slide. Spontaneous viscera slide is more evident with longitudinal scanning of the abdomen because respiration-induced movement is greater in the longitudinal axis than in the transverse axis. Viscera slide induced by manual ballottement is dependent upon the compressive force being applied along the plane being scanned. The occurrence of ultrasonically detected vis-
-
cera slide suggests a possible simple approach to the identification of abdominal wall adhesions prior to laparoscopy or open abdominal surgery. With this point in mind, we conducted a preliminary study in two human subject groups: (1)subjects who were likely to be free of adhesions, and (2) subjects with a greater likelihood of abdominal wall adhesions as a result of previous abdominal operations or past history of peritonitis. This study indicates that ultrasonically detected viscera slide during abdominal scanning is normally present in subjects without previous abdominal surgery, but may be significantly restricted beneath the healed scars of subjects who have had a previous operation or past history of peritonitis. These results suggest that ultrasonically detected viscera slide may be useful for detecting the presence or absence of abdominal wall adhesions. METHODS
From the The Medical College of Pennsylvania, Philadelphia, Pennsylvania. For reprints contact Bernard Sigel, MD, The Medical College of Pennsylvania, 3300 Henry Avenue, Philadelphia, Pennsylvania 19129.
The ultrasound examination was performed with the subject in the supine position. A 5-MHz or 7.5-MHz real-time ultrasound imaging system 375
376
KODAMA ET AL.
FIGURE 1. Two sonograms (A, B) of the abdominal wall at different phases of normal respiration during longitudinal scanning. A normal respiratory excursion of about 3 cm is evident in the movement of the focal area (demarcated by the bracket) in reference t o the metal marker (open arrow) on the skin surface. The metal marker is associated with an acoustic shadow. Solid arrows indicate the junction of the abdominal wall and the abdominal cavity.
was used. Our principal interest was to discover restricted viscera slide suggesting the presence of adhesions between the abdominal structures and the abdominal wall. We usually examined selected sites of interest on the basis of two considerations: first, we scanned beneath healed ab-
dominal scars; second, we scanned sites where surgical incisions were planned. For example, in laparoscopic surgery, the first trocar is often inserted at or just below the umbilicus. In these instances, we evaluated the viscera slide in the umbilical region. Viscera slide was identified in
FIGURE 2. Two sonograms (A, B) of the abdominal wall at different phases of normal respiration over a healed surgical incision during longitudinal scanning. Restricted viscera slide of less than 1 c m is evident i n the movement of the focal area (demarcated by the bracket) i n reference t o a metal marker (open arrow) on the skin surface. The solid arrows indicate the junction of the abdominal wall and the abdominal cavity. JOURNAL OF CLINICAL ULTRASOUND
DETECTION OF VISCERA SLIDE
the real-time ultrasound image by tracking a persistent cluster of structures of varying echogenicity that moved horizontally beneath the more stationary abdominal wall. This persistent cluster was used as a focal area for recognizing viscera slide. The examination began by observing the motion of structures immediately deep to the abdominal wall. This helped us to identify the deep layer of the abdominal wall. Next, attention was given to identifying a moving focal area beneath the abdominal wall whose shape and gray-scale characteristics persisted as the focal area moved through several respiratory excursions. This provided a tracking marker that was used to estimate the distance traversed by the abdominal viscera at the abdominal wall. We began the examination with longitudinal scanning to observe spontaneous viscera slide (producedby respiratory motion) at selected sites of interest. Normal respiratory movements usually produced viscera slide excursions of 1 cm to 2 cm during longitudinal scanning (Figure 1). If the viscera slide appeared to be diminished, the examiner was attentive to possible causes of inadequate respiratory movement, such as impaired respiratory excursions (e.g., chronic obstructive pulmonary disease) or a patient who was not cooperating (e.g., impaired consciousness). When there was any question about the effectiveness of respiratory motion, the patient was asked to take a few deep breaths. During exaggerated respiratory excursions, viscera slide was more pronounced. With exaggerated respirations, longitudinal scanning of viscera slide usually revealed excursions greater than 3 cm. Finally, diminished viscera slide due to inadequate respiratory movement was highly suggested by reduced viscera slide in all areas being examined, whether beneath a scarred or unscarred abdominal wall. Induced viscera slide by manual ballottement of the abdomen by the examiner was performed during all transverse scanning examinations and during longitudinal scanning when there was any question about the adequacy of respiratory movement. Manual compression was applied gently with no more vigor than is used in the routine physical examination of the abdomen. When the manual force ordinarily used in a physical examination was applied along the scan path, viscera slide was observed. During longitudinal scanning, manual compression was applied either superiorly or inferiorly to the transducer in contact with the abdominal wall. During transverse scanning, manual compresVOL. 20, NO. 6, JULYiAUGUST 1992
377
sion was applied at either lateral side of the transducer. The distance traversed by the induced viscera slide was usually less than the distance traversed by spontaneous viscera slide. Induced viscera slide was usually greater than 1 em. When there was a question about impairment of induced viscera slide at a particular location, the extent of the motion excursions at several sites were compared to determine whether the induced viscera slide was restricted locally or generally. We defined restricted viscera slide as movement of less than 1 cm during both longitudinal and transverse scanning (Figure 2). The presence of viscera slide movement was always assessed on the basis of the relationship of the abdominal content t o the abdominal wall. This was a key factor, particularly in viscera slide induced by manual compression. During manual compression of a scarred abdomen with restricted viscera slide, the abdominal wall and abdominal content may be made to move together beneath the transducer. Such bulk motion can be mistaken for viscera slide unless viscera motion is carefully distinguished from abdominal wall motion. RESULTS
Ultrasonic detection of viscera slide has been performed in 42 human subjects (Table 1).The subjects were considered in terms of their potential for having abdominal wall adhesions. One group included 18 subjects who had not undergone previous abdominal surgery and did not have a past history suggesting peritonitis. These subjects, who were not considered at risk for adhesions, were called the “normal” group. The second group included 24 subjects who had previous abdominal operations (23 subjects) or a past history of peritonitis (1 subject). These subjects were considered potentially at risk for adhesions and were called the “risk” group. During longitudinal scanning of members of the normal group, all subjects exhibited spontaneous viscera slide (resulting from respiratory movement) of 1cm or greater during regular respiration and greater than 2.5 cm during exaggerated respiration. Induced viscera slide (resulting from the examiner’s manual compression) was usually between 1cm and 2 cm, but rarely more than 2 cm in the normal group. The extent of induced viscera slide is related to the force of manual compression. The less extensive viscera slide produced by manual compression (as opposed to
KODAMA ET AL.
378
TABLE 1 All Subjects Examined for Viscera Slide Spontaneous Viscera Slide
Induced Viscera Slide
Type of Subject
Number of Subjects
Normal
Restricted
Normal
Restricted
Normal
18 24
18 10
-
18
-
14
14
10
Risk
spontaneous respiratory motion) is probably due to limitations on the acceptable vigor of the compression maneuver, which should be no greater than the force applied in the routine physical examination of the abdomen. Restricted viscera slide was observed in 14 of 24 subjects in the risk group (58.3%).Restricted viscera slide, when found, was beneath a surgical scar in all except 1subject. Restricted viscera slide was more definitively identified in the observations of spontaneous viscera slide on longitudinal scanning. Where longitudinally scanned spontaneous viscera slide was less than 1 cm (after exaggerated respiration), manual compression during both the longitudinal and transverse scans was performed. If spontaneous viscera slide during longitudinal scanning and induced viscera slide during both longitudinal and transverse scanning were less than 1 cm, the viscera slide was considered to be restricted. Abdominal operations within a week of the ultrasound examination were performed in 18 subjects (Table 2). Five of these were from the normal group and did not reveal adhesions. Of the 13 risk group subjects, 6 exhibited normal viscera slide and showed no adhesions at operation. Seven of the 13 risk group subjects exhibited restriction of viscera slide. In 3 of these 7 subjects, only spontaneous viscera slide was restricted. All 7 subjects were found to have adhesions at surgery. In the 3 subjects in whom spontaneous viscera slide was restricted but induced viscera slide was normal, operation revealed either a single dense adhesion or thin filmy adhesions at the site of restricted spontaneous viscera slide. These findings suggest that restriction of sponta-
Percentage Restricted %
0.0
58.3
neous viscera slide may be a more sensitive indicator of adhesions and that a disparity of findings may result from less extensive adhesions. Table 3 presents more detailed information about the 13 risk subjects in whom adhesions were confirmed or excluded at operation. The 6 subjects from the risk group with normal visceral slide and no adhesions at operation had shorter scar lengths (mean = 7.2 cm) than subjects with proven adhesions. The group of 7 risk subjects with operative confirmation of adhesions had generally longer incisions (mean = 16.5 cm) from previous surgical procedures. In addition, those same risk subjects had undergone the more extensive previous operative procedures. Adhesions were localized to the area directly beneath previous operative scars in 5 of the 7 subjects with operative confirmation. Thus, restricted viscera slide at the umbilical region was usually associated with scars that were in proximity to the umbilicus. One patient with a history of pelvic inflammatory disease had diffuse adhesive disease throughout the left and right lower quadrants. In 1 patient who had previously undergone a hysterectomy from a midline incision, the adhesions were found to be localized away from the scar site, in the right lower quadrant. In summary, normal and abnormal viscera slide can be distinctly defined by simple measurement of excursion distances (Table 4). In Table 4, the normal group consists of the 18 normal subjects and the 6 risk subjects who at operation were found not to have adhesions. The abnormal group in Table 4 are the 7 risk patients who revealed adhesions at surgery. Overall, ultrasonically observed viscera slide has been 100% cor-
TABLE 2 Ultrasound Examination Confirmed by Laparoscopy or Laparotomy Type of Subject
Number of Subjects
Normal Risk
13
5
Ultrasound Examination Normal viscera slide Normal viscera slide in 6 Restricted spontaneous and induced viscera slide in 4 Restricted spontaneous and normal induced viscera slide in 3
Operative Findings No adhesions No adhesions Adhesion beneath scar Single or filmy adhesions at the site of restricted viscera slide JOURNAL OF CLINICAL ULTRASOUND
DETECTION OF VISCERA SLIDE
379
TABLE 3 Risk Group Information Viscera Slide Subject No
Normal
1 2
Location
Length
+
Low midline Low midline and low right paramedian
cm 6 12 9
-
-
+
4 5 6
+
7
+ +
8
Restricted
+
3
+
9 10 11 12
+
13
+
Abdominal Wall Scar
+ + + +
Type of Previous Abdominal Operation Hysterectomy Hysterectomy and appendectomy
Beneath scar Beneath midline scar
-
lnfraumbilical lnfraumbilical Low midline
2 10
lnfraumbilical Upper midline Long midline Left paramedian Low midline Long midline
2 12 21 20 11 30
Umbilical hernia repair Laparoscopic tuba1 ligation Hysterectomy and umbilical hernia repair Laparoscopic exploration Exploratory laparotomy Exploratory laparotomy Unknown Cesarian section Aortobifemoral bypass
Low midline
12
Hysterectomy
4
Site of Adhesion
Right and left lower quadrants No adhesions No adhesions Right lower quadrant
No adhesions No adhesions Beneath scar Beneath scar No adhesions Beneath scar and right lower quadrant No adhesions
”This patient has a history of pelvic inflammatory disease.
rect to date in identifying the presence or absence of abdominal wall adhesions. DISCUSSION
This article describes how an ultrasonic finding may be useful in discovering and mapping abdominal wall adhesions. Restricted viscera slide occurred in a high proportion of subjects with previous operations, and it was not evident in subjects without previous abdominal surgery or a history of peritonitis. Further work will be needed to determine just how useful this finding is in detecting adhesions. Such work should focus on the recent heightened interest in the use of laparoscopic surgery by providing better information for the selection of patients for operative procedures and for more precise guidance during placement of laparoscopic instruments. This technique could also be used in identifying and mapping abdominal wall adhesions prior to laparotomy or other invasive abdominal procedures (for example, peritoneal dialysis or lavage). The development of a simple method with the potential t o detect abdominal wall adhesions preoperatively was prompted by an increased recent interest in laparoscopic surgery, particularly therapeutic laparoscopy, such as laparoscopic cholecystectomy. During laparoscopy, the first trocar is inserted “blindly,” but all subsequent trocars are introduced under direct visualization through the portal provided by the initial trocar. The adherence of abdominal viscera and structures (e.g., omentum) to the site of placement of VOL. 20, NO. 6, JULY/AUGUST 1992
the first trocar could result in inadvertent injury to blood vessels or viscera with subsequent complications, such as hemorrhage, perforated viscus, and perit~nitis.’-~ In addition to minimizing the risk of these complications, the preoperative localization of adhesions allows the surgeon to plan the entry portal to avoid the technical difficulties of working in an area of adhesions, therefore reducing potential extended dissections and prolonged operating times. For these reasons, a preoperative imaging technique that could indicate the presence and location of abdominal wall adhesions in patients with previous operations would be very useful. Insertion of saline or gas through a needle is usually performed prior to introduction of the first trocar. However, the apparent easy passage of fluid or gas does not provide complete protection from accidents, and complications have been r e ~ 0 r t e d . lThese ~ ~ limitations have prompted the search for ultrasonic methods to detect adhesions. In 1987, Marin and associates2 reported on an TABLE 4 Normal and Abnormal SpontaneousViscera Slide Distances Group
N
Normal Abnormal
24 7
Normal Respirationsa
Exaggerated Respirationsa
cm 1.6 0.4
3.5 zk 0.9
0.4 + 0.3
0.8 ? 0.2
*
“Data presented are mean in cm +SD.
cm
380
KODAMA ET AL.
ultrasonic technique to detect abdominal adhesions prior to laparoscopy. Their approach was to repeat the ultrasound examination after pneumoperitoneum had been established. Ultrasound examination of an area free of adhesions was “characterized by a large conical shadow, inside which there are dense horizontal hyperechogenic lines due perhaps to the reflection of echoes of the wall layers. When adhesions are present, however, the image is amorphous and irregular, caused by more or less reflective or coarse echoes.” These authors found the postpneumoperitoneum ultrasound examination useful in guiding trocar placement in patients with abdominal adhesions. The technique that we describe has the advantage of being completely noninvasive. The presence and location of adhesions is determined not only prior to laparotomy or laparoscopy, but prior to insertion of a needle to inject saline or gas. For this reason, ultrasonic detection of viscera slide may be used conveniently prior to any surgical maneuver. Such examinations could be performed in any ambulatory ultrasound examination setting. Furthermore, ultrasonic detection of viscera slide to discover and map abdominal wall adhesions could be achieved at the time of other ultrasound examinations to diagnose conditions that may be treated by laparotomy or
laparoscopy. For example, the ultrasound examination that is positive for gallbladder calculi could be extended to include a search for adhesions if such abnormalities are suspected on the basis of previous operations or a history of peritonitis. Thus, a patient with biliary calculi, who is likely to require an operation and who is also at risk for abdominal wall adhesions, may only need to make a single trip to a diagnostic ultrasound facility. In summary, these data indicate that the proposed procedure for detecting abdominal wall adhesions may be clinically significant; however, further experience is needed to verify these early findings. REFERENCES
1. Dagnini G Clinical Luparoscopy. Padova, Piccin Editore, 1978. 2. Kane MG, Krejs GJ: Complications of diagnostic laparoscopy in Dallas: A 7-year prospective study. Gastrointest Endosc 30:237, 1984. 3. Marin G, Bergama S, Miola E, Caldironi MW, Dagnini G Prelaparoscopic echography used to detect abdominal adhesions. Endoscopy 19:147, 1987. 4. Penfield AJ: How to prevent complications of open laparoscopy. J Reprod Med 30:660, 1985. 5. PlePner I, Berndt H, Gutz H-J: Laparoscopy following abdominal operations. Endoscopy 10:187,1978.
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