Author's Accepted Manuscript
Median arcuate ligament compression of the mesenteric vasculature Margaret C. Tracci M.D., J.D.
www.elsevier.com/locate/enganabound
PII: DOI: Reference:
S1089-2516(14)00070-5 http://dx.doi.org/10.1053/j.tvir.2014.12.007 YTVIR438
To appear in: Tech Vasc Interventional Rad
Cite this article as: Margaret C. Tracci M.D., J.D., Median arcuate ligament compression of the mesenteric vasculature, Tech Vasc Interventional Rad , http://dx.doi.org/10.1053/j.tvir.2014.12.007 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Median arcuate ligament compression of the mesenteric vasculature Margaret C. Tracci, M.D., J.D.
Correspondence: Division of Vascular and Endovascular Surgery University of Virginia PO Box 800679 Charlottesville, VA 22908 (434) 243-9493 [email protected] Abstract
Compression of the celiac artery by fibrous bands of the diaphragmatic crura has been
associated with gastrointestinal symptoms such as postprandial pain and delayed gastric emptying, a phenomenon known as Median Arcuate Ligament Syndrome (MALS). The hemodynamic effects of this compression have also been implicated in the development of aneurysms of the celiac artery or its visceral collaterals. Both open surgical and laparoscopic decompression of the celiac artery have proven effective in treatment of the compressive syndrome. Endovascular stent placement has largely supplanted open surgical reconstruction for residual stenosis following compression, but is not recommended absent decompression due to high failure rates. Endovascular techniques have also become the mainstay of management of aneurysmal disease associated with celiac artery compression.
Introduction
Some degree of radiographic compression of the celiac axis by the median arcuate
ligament, which consists of connective tissue fibers bridging the diaphragmatic crura, is observed in 10‐24% of patients.[1] (Figures 1, 2) Symptomatic compression of the celiac artery by the median arcuate ligament, often referred to as median arcuate ligament syndrome (MALS) or celiac artery compression syndrome (CACS) was first described by Harjola in 1963 and is characterized by complaints of abdominal pain, often associated with meals.[2] The traditional mainstay of management has been surgical decompression, which is thought to offer symptomatic relief through alleviation of the arterial stenosis as well as division of nerve tissue associated with the celiac ganglion. Historically, stand‐alone endovascular therapy for celiac artery compression, by angioplasty with or without stent placement, was attended by high failure rates. [3] (Figure 3)
At present, endovascular therapy serves two major roles in the management of MALS
and its sequellae. Endovascular stent placement may be used in conjunction with traditional surgical or minimally invasive techniques of release of the extrinsic compression of the artery as a significantly less morbid alternative to surgical reconstruction. In addition, other splanchnic aneurysms, typically in the pancreaticoduodenal arcade, but also described in the celiac or gastroepiploic arteries, may arise as a result of increased collateral flow dynamics (pancreaticoduodenal, gastroepiploic) or poststenotic dilatation (celiac). [3‐5] Just as celiac stenosis or occlusion associated with MALS is distinguished from atherosclerotic disease, aneurysms arising in this context are considered an entity distinct from those occurring in more
typical scenarios of trauma, pancreatitis, or vasculitis. [3,6] Endovascular embolization techniques are particularly well suited to the treatment of these lesions, which may be multiple. This approach offers significant advantages in morbidity and mortality over historical surgical approaches to these lesions. Clinical evaluation of the patient
Establishing the diagnosis of median arcuate ligament syndrome
Patients with median arcuate ligament compression of the celiac artery frequently
present with complaints of postprandial pain, often of the upper abdomen. A subset of patients presents with symptoms of gastroparesis. Diagnosis relies on the coexistence of these symptoms with angiographic or cross sectional imaging demonstrating compression of the proximal celiac and, at times, even the superior mesenteric, artery by the fibers of the median arcuate ligament. This compression typically begins several millimeters distal to the origin, as opposed to atherosclerotic disease, which ordinarily arises at and predominantly involves the aortic origin of the vessel. Computed tomography or magnetic resonance angiography demonstrate similar findings and may aid in procedural planning by permitting evaluation of celiac angle, diameter, and vessel length. During diagnostic angiography, a lateral view may demonstrate significant respiratory variation with compression particularly evident during expiration. On aortography, nonopacification of the hepatic artery may be noted due to collateral filling via the gastroduodenal artery in the setting of a proximal celiac lesion. Over time, compression and repetitive trauma may result in significant endofibrosis or even occlusion of the artery. Interestingly, there is poor correlation between the presence or severity
of symptoms and the existence or degree of compression observed. Frequently, the medical evaluation is a process of elimination as other potential causes of pain, such as gastritis, gastric ulcer disease, symptomatic gallstones, or pancreatitis, are ruled out. Some have advocated for a full negative gastrointestinal workup, including endoscopy, fluoroscopy, ultrasound, laboratory studies, and computed tomography. [7] Prior to planned surgical decompression, the suitability of the patient for laparotomy or laparoscopy must be established through a thorough history and physical examination, evaluation of cardiac and pulmonary function, and assessment of nutrition status. Whereas the age of patients with atherosclerotic mesenteric disease averaged 68 years in those undergoing open and 74 in those undergoing endovascular procedures, patients with symptomatic median arcuate ligament compression are often in their 3rd to 6th decade and free from atherosclerotic disease and its common comorbidities. [8]
Aneurysmal complications of MAL Compression
Aneurysmal degeneration of the pancreaticoduodenal arcades, gastroepiploic, or celiac
arteries has been described by at least one author in 80% of cases of celiac compression, with a typically reported incidence in this setting of 3‐18%. [9] These aneurysms are, unfortunately, typically asymptomatic except in the setting of rupture. They may be discovered either incidentally or during the evaluation of MAL compression and may be evident on ultrasound, CT, or MR. Once detected, further characterization with dedicated cross‐sectional or angiographic imaging is recommended. Modern 64‐MDCT with thin (submillimeter) collimation permits multiplanar and volume‐rendered 3D reconstruction to permit identification of the
aneurysm’s afferent and efferent vessels and facilitate treatment planning by anticipating optimal angiographic views for vessel visualization, selection, embolization. [10] Indications for the procedure Symptomatic celiac artery compression
Patient selection remains a challenge, as there is relatively poor correlation between the
radiographic finding of celiac artery compression and the presence, type, or severity of symptoms. It is generally accepted that asymptomatic or incidentally discovered celiac artery compression does not warrant intervention. Among symptomatic patients, surgical series suggest that certain characteristics may be associated with successful resolution of symptoms with treatment, while others may be predictive of failure. [11] As minimally invasive surgical decompression becomes more widely adopted, the role of endovascular therapy may be expected to grow, as well. A “hybrid” surgical and endovascular approach is supported by multiple reports of successful treatment of celiac artery compression following surgical decompression since this was first reported in 1980 and nearly 20 years of literature detailing failures of an endovascular‐alone approach in this disease process. [12,13] (Figure 2)
Associated aneurysmal disease
The natural history of splanchnic artery aneurysms is not well understood; there
appears to be a poor correlation between aneurysm size and rupture risk. [3,9] However, pancreaticoduodenal artery aneurysms in particular are felt to carry a high risk of rupture once detected and the rate of mortality associated with rupture remains high. [9,14] Although
consensus has not been reached, most clinicians would advocate for treatment of splanchnic artery aneurysms once they are identified. These are rarely symptomatic, but are more typically found incidentally during imaging and should be carefully screened for when evaluating the imaging of patients with MAL compression. Procedural steps
Surgical decompression Surgical decompression, by open or minimally invasive technique, should precede
endovascular treatment either occlusive or aneurysmal disease associated with median arcuate ligament compression. Traditional surgical therapy requires general anesthesia. The patient is positioned supine and the skin of the abdomen and lower chest prepped with chlorhexidine solution and sterilely draped. A nasogastric tube is placed to facilitate identification and mobilization of the esophagus. An upper midline incision is made, with the length of the incision dictated by the patient’s body habitus, and typically extending to the xiphoid. The esthenic habitus commonly associated with symptomatic celiac artery compression may lend itself to a relatively short incision. The skin is incised and electrocautery used to divide the subcutaneous tissue to the level of the midline fascia. The fascia is then opened in the upper midline and the peritoneal cavity carefully entered under direct visualization. Where obesity or the anatomy of the costal margin and chest dictate, the incision may even be extended along the left side of the xiphoid to facilitate better supraceliac exposure.
The left lobe of the liver is then carefully mobilized by division of the triangular ligament
and carefully retracted, exposing the supraceliac aorta. The esophagus is carefully palpated
using the nasogastric tube as a guide and is mobilized and retracted to the patient’s left side. The crural fibers that constitute the median arcuate ligament may then be divided. As a practical matter, the shepherd’s crook configuration of the compressed artery may render a proximal to distal approach safer and more readily performed. Care must be taken in the mobilization and division of these tissues and associated neural fibers, as they tend to be densely adherent to one another and to the artery, as the celiac is circumferentially freed. The phrenic arteries are also commonly encountered during the course of this dissection and should be carefully ligated with hemoclips or suture if they must be divided, as substantial hemorrhage may result from inadvertent injury or inadequate control.
Laparoscopy is the most widely utilized minimally invasive surgical technique for
decompression of celiac artery compression, although use of the surgical robot has also been described. Laparoscopic decompression is most often accomplished through a five port technique, which permits liver retraction through an upper midline port and provides two additional 5 mm ports on either side for camera and instrumentation. In this approach, the median arcuate ligament may be carefully bluntly mobilized off of the superior surface of the celiac artery, then divided using the harmonic scalpel. Again, care must be taken to identify and control the phrenic arteries if they are encountered. Although no deaths have been reported, emergent conversion to open surgery has, at times attended by significant hemorrhage and the need for postoperative intensive care. [15,16]
Patients not infrequently experience symptomatic relief following decompression
without further steps to dilate or reconstruct the celiac artery or, in some instances, any formal assessment of residual stenosis. Post‐decompression assessment ranges from visual
assessment of the artery, which is likely to miss luminal compromise related to intimal injury, to handheld Doppler or intraoperative duplex, to on‐table angiographic imaging. The latter permits endovascular intervention at the time of surgery to diagnose and address residual stenosis without the need for aortic clamp placement or the morbidity associated with surgical reconstruction. Typically, we advocate the use of duplex ultrasound or CT angiography to evaluate surgical decompression. Should either of these suggest significant residual stenosis, open reconstruction by patch or either interposition or bypass graft may be undertaken or the decompressed artery may be treated with placement of an endovascular stent. The latter approach avoids the risk and hemodynamic impact of open reconstruction. The presence of poststenotic complications such as aneurysmal degeneration of the celiac or its splanchnic branches should prompt the operator to fully address residual stenosis to alleviate the hemodynamic forces implicated in the formation of these aneurysms.
Celiac artery revascularization post decompression
Once extrinsic compression of the celiac artery has been achieved and the decision
made to proceed with endovascular revascularization of the celiac artery. In an institution with hybrid capabilities, this may be performed at the same time as surgical decompression. Typically, it performed in a staged fashion under moderate conscious sedation. The decision to proceed with celiac artery revascularization may planned based on the observation of significant residual stenosis following decompression and historical data demonstrating a higher recurrence rate of symptoms with decompression alone versus decompression and surgical reconstruction (see Expected Outcomes) or on the presence of associated aneurysmal
disease of the celiac or its collaterals based on the rationale that alleviating the stenosis may decrease the risk of progression or recurrence of these lesions.
Retrograde common femoral artery (CFA) access may be used. Once diagnostic
aortography has been performed, a7 French, 40 cm sheath is advanced. The patient is anticoagulated with intraarterial or intravenous unfractionated heparin per institutional protocol. An appropriately shaped 5 French catheter is then chosen and used in conjunction with an angled 0.035” hydrophilic guidewire to select the origin of the celiac artery. The wire and catheter are then carefully advanced. The hydrophilic wire is exchanged for a relatively stiff 80 cm 0.035” wire, such as a Rosen (multiple manufacturers), and the sheath is carefully advanced into the origin of the celiac artery. Cannulation of the celiac artery may be achieved in anterior‐posterior or lateral view, but the latter should be used during stent placement. The catheter is removed and an appropriately sized balloon‐expandable stent is advanced across the stenotic region of the celiac, typically extending 2‐3 mm into the aorta. The use of a covered stent may reduce the incidence of post‐stent intimal hyperplasia (figure). The sheath is withdrawn to expose the stent and appropriate stent positioning confirmed as needed using additional imaging through the sheath. The stent is then deployed, with postdilation as needed. Of note, similar technique may be used to address fusiform celiac artery aneurysm, although celiac anatomy typically dictates embolization and coverage of left gastric and even splenic arteries in order to achieve effective aneurysm exclusion. (Figures 3(a‐d))
Complications
Stent fracture (Figure 2)
Stent fracture was often historically managed with open reconstruction. However, if the
median arcuate ligament is fully released, relining the celiac artery with a balloon‐expandable covered stent may suffice.
In‐stent stenosis (Figure 4)
In‐stent stenosis, at times quite impressive, has been observed. Covered stents may
provide some advantage over balloon‐expandable uncovered stents in this regard. Restenosis of an uncovered stent may also be addressed by relining the affected portion of the artery with a balloon‐expandable covered stent. Treatment of associated aneurysms: pancreaticoduodenal artery aneurysm (for detailed technical description, see Endovascular Management of Visceral Aneurysms) Clinical follow‐up Surgical decompression and open or endovascular celiac artery revascularization/reconstruction Following surgical decompression, the patient is typically seen at a week from hospital discharge to assess wound healing and surgical recovery. At 4‐6 weeks, visceral duplex or CT angiography is performed to assess the effectiveness of decompression. If the patient has experience symptomatic relief from decompression alone and has recovered well from surgery,
further followup is on an as‐needed basis. Surgical or endovascular reconstruction, if performed, is assessed at 3 month, 6 month, and then annual intervals after the first year, typically using duplex ultrasound to detect restenosis or occlusion. Endovascular treatment of pancreaticoduodenal or gastroepiploic aneurysms
Interval angiography provides the most reliable evaluation following embolization of
pancreaticoduodenal or gastroepiploic aneurysms. We recommend a single followup angiographic study 1‐3 months postembolization. The literature does not yet reflect reports of rupture or recurrence following successfully embolization. Presumably, if the inciting factor of celiac artery stenosis or occlusion due to compression has been removed by decompression and appropriate open or endovascular reconstruction, the risk of recurrence should vanishingly small. Unfortunately, the utility CT and MR imaging in subsequently evaluating an aneurysm postembolization are significant compromised by artifact. (Figure 5 a,b)
Expected outcomes
Treatment of MALS
The literature offers a broad range of reported rates of symptom recurrence following
surgical decompression of the celiac artery, most likely reflecting the heterogeneity of population, preoperative evaluation, and operator criteria for offering release. Reilly, et al. noted several important clinical points. There was not a significant correlation between the angiographic degree of compression, expressed as percentage narrowing. A significant percentage of patients (8/15) experienced relief following MAL release alone, but these
patients were more likely to suffer from symptom recurrence (44%) than those who underwent some form of revascularization (22%), supporting the contention that residual stenosis should be considered for treatment. Endovascular therapy obviously offers the advantage of permitting staged treatment of residual stenosis in a patient who remains symptomatic after MAL release without the disadvantage of requiring a full (if the initial release was laparoscopic) or repeat (if the initial release was open) laparotomy. A number of clinical features appeared to have a bearing on clinical success. Relief of symptoms was more likely to be achieved in patients presenting with a postprandial pain pattern, those aged 40‐60 years), women, those exhibiting significant (>20 lb) weight loss, and angiography demonstrating anatomic and physiological changes such as poststenotic dilatation of the celiac artery or increased collateral flow. A failure to achieve sustained symptom relief was associated with age > 60, an atypical pain pattern including periods of remission, and preoperative weight loss
Median arcuate ligament compression of the mesenteric vasculature Margaret C. Tracci M.D., J.D.
www.elsevier.com/locate/enganabound
PII: DOI: Reference:
S1089-2516(14)00070-5 http://dx.doi.org/10.1053/j.tvir.2014.12.007 YTVIR438
To appear in: Tech Vasc Interventional Rad
Cite this article as: Margaret C. Tracci M.D., J.D., Median arcuate ligament compression of the mesenteric vasculature, Tech Vasc Interventional Rad , http://dx.doi.org/10.1053/j.tvir.2014.12.007 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Median arcuate ligament compression of the mesenteric vasculature Margaret C. Tracci, M.D., J.D.
Correspondence: Division of Vascular and Endovascular Surgery University of Virginia PO Box 800679 Charlottesville, VA 22908 (434) 243-9493 [email protected] Abstract
Compression of the celiac artery by fibrous bands of the diaphragmatic crura has been
associated with gastrointestinal symptoms such as postprandial pain and delayed gastric emptying, a phenomenon known as Median Arcuate Ligament Syndrome (MALS). The hemodynamic effects of this compression have also been implicated in the development of aneurysms of the celiac artery or its visceral collaterals. Both open surgical and laparoscopic decompression of the celiac artery have proven effective in treatment of the compressive syndrome. Endovascular stent placement has largely supplanted open surgical reconstruction for residual stenosis following compression, but is not recommended absent decompression due to high failure rates. Endovascular techniques have also become the mainstay of management of aneurysmal disease associated with celiac artery compression.
Introduction
Some degree of radiographic compression of the celiac axis by the median arcuate
ligament, which consists of connective tissue fibers bridging the diaphragmatic crura, is observed in 10‐24% of patients.[1] (Figures 1, 2) Symptomatic compression of the celiac artery by the median arcuate ligament, often referred to as median arcuate ligament syndrome (MALS) or celiac artery compression syndrome (CACS) was first described by Harjola in 1963 and is characterized by complaints of abdominal pain, often associated with meals.[2] The traditional mainstay of management has been surgical decompression, which is thought to offer symptomatic relief through alleviation of the arterial stenosis as well as division of nerve tissue associated with the celiac ganglion. Historically, stand‐alone endovascular therapy for celiac artery compression, by angioplasty with or without stent placement, was attended by high failure rates. [3] (Figure 3)
At present, endovascular therapy serves two major roles in the management of MALS
and its sequellae. Endovascular stent placement may be used in conjunction with traditional surgical or minimally invasive techniques of release of the extrinsic compression of the artery as a significantly less morbid alternative to surgical reconstruction. In addition, other splanchnic aneurysms, typically in the pancreaticoduodenal arcade, but also described in the celiac or gastroepiploic arteries, may arise as a result of increased collateral flow dynamics (pancreaticoduodenal, gastroepiploic) or poststenotic dilatation (celiac). [3‐5] Just as celiac stenosis or occlusion associated with MALS is distinguished from atherosclerotic disease, aneurysms arising in this context are considered an entity distinct from those occurring in more
typical scenarios of trauma, pancreatitis, or vasculitis. [3,6] Endovascular embolization techniques are particularly well suited to the treatment of these lesions, which may be multiple. This approach offers significant advantages in morbidity and mortality over historical surgical approaches to these lesions. Clinical evaluation of the patient
Establishing the diagnosis of median arcuate ligament syndrome
Patients with median arcuate ligament compression of the celiac artery frequently
present with complaints of postprandial pain, often of the upper abdomen. A subset of patients presents with symptoms of gastroparesis. Diagnosis relies on the coexistence of these symptoms with angiographic or cross sectional imaging demonstrating compression of the proximal celiac and, at times, even the superior mesenteric, artery by the fibers of the median arcuate ligament. This compression typically begins several millimeters distal to the origin, as opposed to atherosclerotic disease, which ordinarily arises at and predominantly involves the aortic origin of the vessel. Computed tomography or magnetic resonance angiography demonstrate similar findings and may aid in procedural planning by permitting evaluation of celiac angle, diameter, and vessel length. During diagnostic angiography, a lateral view may demonstrate significant respiratory variation with compression particularly evident during expiration. On aortography, nonopacification of the hepatic artery may be noted due to collateral filling via the gastroduodenal artery in the setting of a proximal celiac lesion. Over time, compression and repetitive trauma may result in significant endofibrosis or even occlusion of the artery. Interestingly, there is poor correlation between the presence or severity
of symptoms and the existence or degree of compression observed. Frequently, the medical evaluation is a process of elimination as other potential causes of pain, such as gastritis, gastric ulcer disease, symptomatic gallstones, or pancreatitis, are ruled out. Some have advocated for a full negative gastrointestinal workup, including endoscopy, fluoroscopy, ultrasound, laboratory studies, and computed tomography. [7] Prior to planned surgical decompression, the suitability of the patient for laparotomy or laparoscopy must be established through a thorough history and physical examination, evaluation of cardiac and pulmonary function, and assessment of nutrition status. Whereas the age of patients with atherosclerotic mesenteric disease averaged 68 years in those undergoing open and 74 in those undergoing endovascular procedures, patients with symptomatic median arcuate ligament compression are often in their 3rd to 6th decade and free from atherosclerotic disease and its common comorbidities. [8]
Aneurysmal complications of MAL Compression
Aneurysmal degeneration of the pancreaticoduodenal arcades, gastroepiploic, or celiac
arteries has been described by at least one author in 80% of cases of celiac compression, with a typically reported incidence in this setting of 3‐18%. [9] These aneurysms are, unfortunately, typically asymptomatic except in the setting of rupture. They may be discovered either incidentally or during the evaluation of MAL compression and may be evident on ultrasound, CT, or MR. Once detected, further characterization with dedicated cross‐sectional or angiographic imaging is recommended. Modern 64‐MDCT with thin (submillimeter) collimation permits multiplanar and volume‐rendered 3D reconstruction to permit identification of the
aneurysm’s afferent and efferent vessels and facilitate treatment planning by anticipating optimal angiographic views for vessel visualization, selection, embolization. [10] Indications for the procedure Symptomatic celiac artery compression
Patient selection remains a challenge, as there is relatively poor correlation between the
radiographic finding of celiac artery compression and the presence, type, or severity of symptoms. It is generally accepted that asymptomatic or incidentally discovered celiac artery compression does not warrant intervention. Among symptomatic patients, surgical series suggest that certain characteristics may be associated with successful resolution of symptoms with treatment, while others may be predictive of failure. [11] As minimally invasive surgical decompression becomes more widely adopted, the role of endovascular therapy may be expected to grow, as well. A “hybrid” surgical and endovascular approach is supported by multiple reports of successful treatment of celiac artery compression following surgical decompression since this was first reported in 1980 and nearly 20 years of literature detailing failures of an endovascular‐alone approach in this disease process. [12,13] (Figure 2)
Associated aneurysmal disease
The natural history of splanchnic artery aneurysms is not well understood; there
appears to be a poor correlation between aneurysm size and rupture risk. [3,9] However, pancreaticoduodenal artery aneurysms in particular are felt to carry a high risk of rupture once detected and the rate of mortality associated with rupture remains high. [9,14] Although
consensus has not been reached, most clinicians would advocate for treatment of splanchnic artery aneurysms once they are identified. These are rarely symptomatic, but are more typically found incidentally during imaging and should be carefully screened for when evaluating the imaging of patients with MAL compression. Procedural steps
Surgical decompression Surgical decompression, by open or minimally invasive technique, should precede
endovascular treatment either occlusive or aneurysmal disease associated with median arcuate ligament compression. Traditional surgical therapy requires general anesthesia. The patient is positioned supine and the skin of the abdomen and lower chest prepped with chlorhexidine solution and sterilely draped. A nasogastric tube is placed to facilitate identification and mobilization of the esophagus. An upper midline incision is made, with the length of the incision dictated by the patient’s body habitus, and typically extending to the xiphoid. The esthenic habitus commonly associated with symptomatic celiac artery compression may lend itself to a relatively short incision. The skin is incised and electrocautery used to divide the subcutaneous tissue to the level of the midline fascia. The fascia is then opened in the upper midline and the peritoneal cavity carefully entered under direct visualization. Where obesity or the anatomy of the costal margin and chest dictate, the incision may even be extended along the left side of the xiphoid to facilitate better supraceliac exposure.
The left lobe of the liver is then carefully mobilized by division of the triangular ligament
and carefully retracted, exposing the supraceliac aorta. The esophagus is carefully palpated
using the nasogastric tube as a guide and is mobilized and retracted to the patient’s left side. The crural fibers that constitute the median arcuate ligament may then be divided. As a practical matter, the shepherd’s crook configuration of the compressed artery may render a proximal to distal approach safer and more readily performed. Care must be taken in the mobilization and division of these tissues and associated neural fibers, as they tend to be densely adherent to one another and to the artery, as the celiac is circumferentially freed. The phrenic arteries are also commonly encountered during the course of this dissection and should be carefully ligated with hemoclips or suture if they must be divided, as substantial hemorrhage may result from inadvertent injury or inadequate control.
Laparoscopy is the most widely utilized minimally invasive surgical technique for
decompression of celiac artery compression, although use of the surgical robot has also been described. Laparoscopic decompression is most often accomplished through a five port technique, which permits liver retraction through an upper midline port and provides two additional 5 mm ports on either side for camera and instrumentation. In this approach, the median arcuate ligament may be carefully bluntly mobilized off of the superior surface of the celiac artery, then divided using the harmonic scalpel. Again, care must be taken to identify and control the phrenic arteries if they are encountered. Although no deaths have been reported, emergent conversion to open surgery has, at times attended by significant hemorrhage and the need for postoperative intensive care. [15,16]
Patients not infrequently experience symptomatic relief following decompression
without further steps to dilate or reconstruct the celiac artery or, in some instances, any formal assessment of residual stenosis. Post‐decompression assessment ranges from visual
assessment of the artery, which is likely to miss luminal compromise related to intimal injury, to handheld Doppler or intraoperative duplex, to on‐table angiographic imaging. The latter permits endovascular intervention at the time of surgery to diagnose and address residual stenosis without the need for aortic clamp placement or the morbidity associated with surgical reconstruction. Typically, we advocate the use of duplex ultrasound or CT angiography to evaluate surgical decompression. Should either of these suggest significant residual stenosis, open reconstruction by patch or either interposition or bypass graft may be undertaken or the decompressed artery may be treated with placement of an endovascular stent. The latter approach avoids the risk and hemodynamic impact of open reconstruction. The presence of poststenotic complications such as aneurysmal degeneration of the celiac or its splanchnic branches should prompt the operator to fully address residual stenosis to alleviate the hemodynamic forces implicated in the formation of these aneurysms.
Celiac artery revascularization post decompression
Once extrinsic compression of the celiac artery has been achieved and the decision
made to proceed with endovascular revascularization of the celiac artery. In an institution with hybrid capabilities, this may be performed at the same time as surgical decompression. Typically, it performed in a staged fashion under moderate conscious sedation. The decision to proceed with celiac artery revascularization may planned based on the observation of significant residual stenosis following decompression and historical data demonstrating a higher recurrence rate of symptoms with decompression alone versus decompression and surgical reconstruction (see Expected Outcomes) or on the presence of associated aneurysmal
disease of the celiac or its collaterals based on the rationale that alleviating the stenosis may decrease the risk of progression or recurrence of these lesions.
Retrograde common femoral artery (CFA) access may be used. Once diagnostic
aortography has been performed, a7 French, 40 cm sheath is advanced. The patient is anticoagulated with intraarterial or intravenous unfractionated heparin per institutional protocol. An appropriately shaped 5 French catheter is then chosen and used in conjunction with an angled 0.035” hydrophilic guidewire to select the origin of the celiac artery. The wire and catheter are then carefully advanced. The hydrophilic wire is exchanged for a relatively stiff 80 cm 0.035” wire, such as a Rosen (multiple manufacturers), and the sheath is carefully advanced into the origin of the celiac artery. Cannulation of the celiac artery may be achieved in anterior‐posterior or lateral view, but the latter should be used during stent placement. The catheter is removed and an appropriately sized balloon‐expandable stent is advanced across the stenotic region of the celiac, typically extending 2‐3 mm into the aorta. The use of a covered stent may reduce the incidence of post‐stent intimal hyperplasia (figure). The sheath is withdrawn to expose the stent and appropriate stent positioning confirmed as needed using additional imaging through the sheath. The stent is then deployed, with postdilation as needed. Of note, similar technique may be used to address fusiform celiac artery aneurysm, although celiac anatomy typically dictates embolization and coverage of left gastric and even splenic arteries in order to achieve effective aneurysm exclusion. (Figures 3(a‐d))
Complications
Stent fracture (Figure 2)
Stent fracture was often historically managed with open reconstruction. However, if the
median arcuate ligament is fully released, relining the celiac artery with a balloon‐expandable covered stent may suffice.
In‐stent stenosis (Figure 4)
In‐stent stenosis, at times quite impressive, has been observed. Covered stents may
provide some advantage over balloon‐expandable uncovered stents in this regard. Restenosis of an uncovered stent may also be addressed by relining the affected portion of the artery with a balloon‐expandable covered stent. Treatment of associated aneurysms: pancreaticoduodenal artery aneurysm (for detailed technical description, see Endovascular Management of Visceral Aneurysms) Clinical follow‐up Surgical decompression and open or endovascular celiac artery revascularization/reconstruction Following surgical decompression, the patient is typically seen at a week from hospital discharge to assess wound healing and surgical recovery. At 4‐6 weeks, visceral duplex or CT angiography is performed to assess the effectiveness of decompression. If the patient has experience symptomatic relief from decompression alone and has recovered well from surgery,
further followup is on an as‐needed basis. Surgical or endovascular reconstruction, if performed, is assessed at 3 month, 6 month, and then annual intervals after the first year, typically using duplex ultrasound to detect restenosis or occlusion. Endovascular treatment of pancreaticoduodenal or gastroepiploic aneurysms
Interval angiography provides the most reliable evaluation following embolization of
pancreaticoduodenal or gastroepiploic aneurysms. We recommend a single followup angiographic study 1‐3 months postembolization. The literature does not yet reflect reports of rupture or recurrence following successfully embolization. Presumably, if the inciting factor of celiac artery stenosis or occlusion due to compression has been removed by decompression and appropriate open or endovascular reconstruction, the risk of recurrence should vanishingly small. Unfortunately, the utility CT and MR imaging in subsequently evaluating an aneurysm postembolization are significant compromised by artifact. (Figure 5 a,b)
Expected outcomes
Treatment of MALS
The literature offers a broad range of reported rates of symptom recurrence following
surgical decompression of the celiac artery, most likely reflecting the heterogeneity of population, preoperative evaluation, and operator criteria for offering release. Reilly, et al. noted several important clinical points. There was not a significant correlation between the angiographic degree of compression, expressed as percentage narrowing. A significant percentage of patients (8/15) experienced relief following MAL release alone, but these
patients were more likely to suffer from symptom recurrence (44%) than those who underwent some form of revascularization (22%), supporting the contention that residual stenosis should be considered for treatment. Endovascular therapy obviously offers the advantage of permitting staged treatment of residual stenosis in a patient who remains symptomatic after MAL release without the disadvantage of requiring a full (if the initial release was laparoscopic) or repeat (if the initial release was open) laparotomy. A number of clinical features appeared to have a bearing on clinical success. Relief of symptoms was more likely to be achieved in patients presenting with a postprandial pain pattern, those aged 40‐60 years), women, those exhibiting significant (>20 lb) weight loss, and angiography demonstrating anatomic and physiological changes such as poststenotic dilatation of the celiac artery or increased collateral flow. A failure to achieve sustained symptom relief was associated with age > 60, an atypical pain pattern including periods of remission, and preoperative weight loss
