Mesenteric Ischemia Current Concepts

Transcription

1 Mesenteric Ischemia Current Concepts Eric D. Endean, MD Gordon L Hyde Professor and Chair in Vascular Surgery University of Kentucky College of Medicine

2 No Financial Disclosures - 2 -

3 - 3 - Not: Louisville Home to Kentucky Derby Kentucky leads the nation in: Smoking Cancer deaths Obesity Coronary disease Hypertension Hyperlipidemia Basketball University of Kentucky Lexington University of Louisville

4 Objectives Review anatomy and pathophysiology as relates to mesenteric ischemia Discuss: Acute mesenteric ischemia Chronic mesenteric ischemia - 4 -

5 Epidemiology Arterial occlusive disease of the mesenteric vessels tends to affect older patient population 17.5% of patients > 65 years with critical stenosis of at least one mesenteric vessel on duplex (Wilson, Arch Intern Med. 166; 2006) Female-to-Male ratio of 3 : 1 Acute mesenteric ischemia: /100,000 admissions Chronic mesenteric ischemia: 1/100,000 admissions Symptoms generally do not develop until 2 or more mesenteric vessels have severe stenosis Delay in diagnosis Many causes of abdominal pain Relative rarity of the disease - 5 -

6 Anatomy Three main mesenteric arteries Celiac Artery Superior mesenteric artery Inferior mesenteric artery Collateral communication Celiac-SMA: Gastroduodenal superior and inferior pancreaticoduodenal SMA-IMA: Marginal artery of Drummond, Arc of Riolan Hypogatsric (middle and inferior rectal) IMA (superior rectal) In chronic disease, usually observe at least 2 vessel disease Celiac artery Gastroduodenal SMA Superior Rectal Arc of Riolan Marginal artery of Drummond IMA Hypogastric - 6 -

7 Acute Mesenteric Ischemia - 7 -

8 Pathophysiology Arterial thrombosis Interruption of perfusion: Ischemia Infarction Vasodilation Resistance Paradoxical vasoconstriction Inadequate recruitment of collateral flow

9 Life-threatening condition Historically: 70% - 90% mortality Contemporary: 60% - 80% UK experience: ~60% Two treatment goals: Acute Mesenteric Ischemia Restoration of blood flow to intestine Preservation of intestine Need early diagnosis Because it is relatively uncommon, may not be considered initially Intervene before bowel necrosis Time is of the essence! - 9 -

10 Etiology Embolic occlusion Thrombosis of underlying atherosclerotic disease Mesenteric venous thrombosis Non-occlusive mesenteric ischemia Isolated SMA dissection Colon ischemia related to aortic surgery Malperfusion with aortic dissection

11 Acute Mesenteric Ischemia Arterial Embolus Accounts for about 50% of AMI Sudden onset of abdominal pain Pain out of proportion of the physical exam Often associated with gut emptying vomit, bowel movement Usually embolus to SMA Cardiac source: History of a fib, MI, ventricular aneurysm Embolus lodges in area of vessel narrowing often distal to initial jejunal branches (follow SMA on CTA!) Results in sparing of the proximal jejunum, ischemia of distal jejunum, ileum, ascending colon No reliable laboratory study usually WBC and lactate are elevated

12 Embolus - Treatment Emergent condition Embolectomy Expose SMA at base of mesentery Retract transverse colon mesentery cephalad Retract small bowel mesentery caudad SMA lies deep and to patient s left of the SMV Control jejunal branches Transverse arteriotomy Careful embolectomy distally avoid perforating/rupturing mesenteric branches Evaluation of bowel viability Resect all infarcted bowel Consider second look laparotomy

13 Acute Mesenteric Ischemia Arterial Thrombosis Accounts for 25% - 30% of AMI Typically older patients Abdominal pain may be more gradual in onset (hours as opposed to sudden onset) May not have a prior history of weight loss/post-prandial pain Often have other manifestations of atherosclerotic disease Abnormal pulse exam, ABI History of other vascular intervention (CEA, bypass, angioplasty) History of CAD MI, CABG Strong history of smoking No reliable laboratory marker Elevation of WBC, lactate

14 Arterial Thrombosis - Treatment Occlusion is typically at the vessel origin Proximal jejunum is ischemic Revascularization Bypass Retrograde or antegrade Prosthetic or autogenous Thrombectomy with angioplasty (retrograde) Thrombolysis with angioplasty/stent Evaluation of bowel viability Resect infarcted bowel Consider second look laparotomy

15 Acute Mesenteric Ischemia Venous Thrombosis Younger patient More insidious in onset Often seen in ED for abdominal pain Gastroenteritis Repeated evaluation for abdominal pain CT scan thrombus in SMV/portal vein with enhancing rim Risk factors: Personal history or family history of hypercoagulable disorder (Protein C/S deficiency, ATIII deficiency, polycythemia, thrombocytosis, malignancy, antiphospholipid antibodies) Cirrhosis Post-splenectomy patients May have elevated WBC

16 Mesenteric Venous Thrombosis - Treatment Anticoagulation Heparin initially Life long anticoagulation (Rhee, J Vasc Surg. 20; 1994) Fluid Resuscitation Evaluation for hypercoagulable state Bowel rest Parenteral antibiotics Laparotomy reserved for peritoneal signs May have severe bowel edema unable to close abdomen Bowel will be congested/plethoric appearing

17 Thrombolysis for Mesenteric Venous Thrombosis Trans-jugular or trans-hepatic placement of infusion catheter Trans-hepatic placement of EKOS catheter in portal vein Abdel-Aal, Vasc Endovasc Surg. 48; 2014 Systemic infusion of thrombolytic agents (tpa) Robin, Lancet. 331; 1988 Infusion of thrombolytics into SMA Hollingshead, J Vasc Inter Rad. 16; 2005 Limited series/case reports Fairly good outcome with anticoagulation, therefore is added risk of thrombolysis needed?

18 Non-occlusive Mesenteric Ischemia Accounts for about 20% of AMI Splanchnic vasoconstriction Decrease in cardiac output Hypovolemia Dehydration Vasopressor agents Typical presentation: patient in CT ICU, post-op from valve replacement, intubated with distended abdomen, elevated WBC, tube fee intolerant (Adult NEC) Myocardial dysfunction Vasopressor support Treated with Lasix

19 Non-Occlusive AMI - Treatment Patchy and diffuse bowel ischemia Treat the underlying cause Improve cardiac function Wean vasopressors Restore intravascular volume Intra-arterial infusion of vasodilator Papaverine, mg/hour Discontinue digitalis Consider glucagon Inotropic effect ( myocardium camp) Mesenteric vasodilation (in rats) Parenteral antibiotics Repeat angiogram in hours Laparotomy for peritoneal signs

20 Isolated SMA Dissection Spontaneous, isolated dissection % in autopsy series Prior to 2007: Morris reported on 71 cases* : 226 cases compiled by Ahn** Not a topic found in Rutherford s Vascular Surgery (8 th Edition) Patient characteristics (symptomatic): More often affects men (85%) than women (15%) Typically in 5 th decade of life Abdominal pain (100%) due to dissection, not intestinal ischemia Hypertension (44%) Hyperlipidemia (41%) Smoking (37%) Abdominal tenderness (33%) Possible association with Marfan s Syndrome, fibromuscular dysplasia, Ehlers-Danlos Syndrome, cystic medial necrosis Rare cause of bowel infarction Diagnostic method of choice - CTA *Morris J Vasc Surg 2008 **Ahn, An Vasc Surg 2014

21 SMA Dissection - Location Typically found at the convex curvature of the SMA 14% Zone 1 64% Zone 2 21% Zone 3 Mean distance from SMA ostium 3 cm Area of SMA that is possibly more susceptible to shearing forces due to relationship to the pancreas Creation of complex flow dynamics at convex part of SMA (Park, J Vasc Surg 2011) Li, J Vasc Surg 2014

22 Classification of Dissection A number of proposed classifications take in account: Presence or absence of false lumen thrombosis Compression of true lumen Occlusion of SMA Aneurysmal change Classification by Yun Type I Patent true and false lumen Type II Patent true lumen IIa False lumen: blind pouch IIb Thrombosed false lumen Type III Dissection with SMA occlusion Yun, Eur J Endovasc Surg 2009

23 Classification of Dissection patients: 41% Type I 50% Type II 9% Type III Incidentally found lesions (no symptoms): 7/10 (70%) Type I Symptomatic patients: 13/22 (69%) Type II Severity of symptoms correlated with length of dissection not type of dissection Yun, Eur J Endovasc Surg 2009

24 Treatment of SMA Dissection Historically, treated aggressively Conservative Management Bowel rest Intravenous fluid Anticoagulation heparin, antiplatelet agent Prevent thrombus propagation Yun* suggests anticoagulation not necessary Indications for Invasive Management Signs of bowel infarction Arterial rupture Persistent abdominal pain ± Severe compression of true lumen Aneurysmal change of SMA *Yun, Eur J Endovasc Surg 2009

25 Open Treatment Open Surgical approach Interposition graft Bypass Antegrade Retrograde (from aorta or iliac artery) Excision of dissection flap with patch angioplasty SMV

26 Endovascular treatment Endovascular treatment Antegrade angioplasty/stent Bare metal Covered Retrograde angioplasty/stent Hybrid Gobble, JVS,

27 Treatment Results An Vasc Surg. 2014;28: patients with SMA dissection with follow up between Initial conservative treatment 172 (78.5%) 15 failures (6.8%) Persistent/recurrent abdominal pain (7) Aneurysm (7) Death (1) All failures (but death) successfully treated with endovascular procedure Initial open surgical treatment 14 (6.4%) Initial endovascular treatment 25 (11.4%) Bowel resection 8 (3.6%)

28 Acute Mesenteric Ischemia Colon Ischemia Complication of aortic surgery Higher incidence after repair of ruptured AAA Hypotension Hematoma compromising mesenteric flow Inadequate hypogastric flow Ligation of IMA Ernst and Hagihara (Ann Surg, 1978) IMA stump pressure > 40 mm Hg IMA/systemic pressure > 0.4 Incidence of ischemic colitis:11/163 (higher in ruptured AAA) (Surg Gynecol Obst, 1979) Prevention! - Preserve hypogastric flow, re-implant IMA for poor flow Sigmoidoscopy for early BM, bloody stool Broad spectrum antibiotic Resuscitation Colectomy for full thickness ischemia

29 Chronic Mesenteric Ischemia

30 Patient Case History 45-year-old woman with post prandial pain, weight loss 6 years previously Aorto-celiac-SMA bypass Graft failed Went to University of Michigan Transaortic endarterectomy Occlusion of mesenteric vessels Hostile abdomen Diagnostic angiogram was obtained

31 Chronic Ischemia How should this patient be approached?

32 Chronic Mesenteric Ischemia - Etiology >90% due to atherosclerotic disease, usually at origin of mesenteric vessels Non-atherosclerotic causes Giant cell arteritis Takayasu s disease Polyarteritis nodosa Fibromuscular dysplasia Neurofibromatosis Radiation arteritis Drug-related Cocaine, Ergot Abdominal aortic coarctation Buerger s disease Systemic lupus erythematosis

33 Chronic Mesenteric Ischemia Age group typically Male : Female ratio 1 : 3 Symptoms Abdominal pain Mid-abdominal/epigastric, crampy, or dull Post prandial related to quantity and type of food Begins within 30 minutes and may last 5 6 hours Food Fear patients avoid food that elicits pain Weight loss, malnutrition, cachexia (looks like advanced cancer) Physical exam Abdominal bruit (50%) Muscle wasting, flat abdomen, cachexia Other manifestations of peripheral vascular disease Coronary disease (50% - 70%) Cerebrovascular (20% - 45%) Peripheral (20% - 35%)

34 Diagnostic Tests Laboratory abnormality non-specific Rule out other disease processes gall bladder disease, PUD, IBD Mesenteric Duplex CTA Good screening test Elevated velocities in SMA, celiac, IMA Provides accurate evaluation of mesenteric vessels, extent of disease, other vessels (aorta/iliac), bowel wall changes, other intra-abdominal pathology Disadvantages: Expense, radiation exposure, risk of contrast (renal toxicity, allergy) Arteriography Include biplane images Venous phase

35 Indication for Treatment No place for conservative treatment for symptomatic patients Goal is to restore normal blood flow to bowel Relieve symptoms Achieve normal weight Prevent bowel infarction Asymptomatic patient Close surveillance Prophylactic revascularization for patients that have multiple mesenteric vessels with high-grade stenosis Prevention of acute mesenteric ischemia with bowel infarction Peri-pancreatic artery aneurysms have association with mesenteric occlusion (celiac artery) Bypass at time of aneurysm repair

36 Treatment Open surgical Bypass Antegrade aorto-mesenteric: Bifurcated graft to two vessels Retrograde: Iliac or infrarenal aortic to SMA bypass Trans-aortic endarterectomy Endovascular Angioplasty and stent

37 Retrograde Bypass Harvest deep vein GSV or Deep vein Deep vein: Invert vein and lyse valves under direct vision Retract right or left colon Exposure of Left or Right common or external iliac artery Tunnel through bowel mesentery Distal anastomosis Side-side anastomosis to SMA with end-side to hepatic End-side anastomosis to SMA

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39 Endovascular Treatment Brachial or femoral approach Brachial may be preferred due to the angle that the SMA makes with the aorta Maintain wire in main SMA Placement in jejunal branch risks perforation Consider embolic protection device Typically use a balloon expandable stent Proximal end should protrude into aorta to treat ostial lesion? Bare metal stent vs. covered stent

40 Covered or Bare Metal Stent? Retrospective review of outcome following stenting of mesenteric vessels 225 patients Bare metal stent (BMS) 164 patients, 197 vessels Covered stent (CS) 61 patients, 67 vessels Freedom from Restenosis Symptom recurrence Reintervention Primary patency (3 yrs) Primary Intervention (mean follow-up 29±12 months) CS 92±6% 92±4% 91±6% 92±4% BMS 53±4%* 50±5%* 56±5%* 52±5%* Secondary Intervention (mean follow-up 24±9 months) Freedom from Restenosis Symptom recurrence Reintervention Primary patency (1 yr) CS 89±10% 100% 100% 100% BMS 49±14%* 64±9%* 72±9%* 63±9%** * p<0.05, **p=0.054, Oderich, et al, J Vasc Surg 2013;58:

41 Retrograde SMA stent

42 Median Arcuate Ligament Syndrome Compression of celiac artery during full expiration Symptoms can develop or be exacerbated with exercise Relatively common finding on CT scan but few have symptoms There is little theoretical justification to believe that this compression could lead to ischemic symptoms given the rich collateral network between the celiac axis and the SMA and the fact that the SMA is usually the most significant visceral vessel in terms of gut perfusion. (Huber, Lee, Seeger. Rutherford s Vascular Surgery, 6 th Edition)

43 Median Arcuate Ligament Syndrome Difficult diagnosis - diagnosis of exclusion Significant portion of individuals will have evidence of celiac compression with expiration - No symptoms Eidt, et al (Vasc Endovasc Surg, 2009) Selective mesenteric angiography Injection of vasodilator in SMA Reproduction of symptoms and loss of collateral filling of celiac vessels 8 patients 4 positive findings patients treated surgically 3 remain asymptomatic 1 mild abdominal symptoms 4 negative studies 2 patients with other causes

44 Median Arcuate Ligament Syndrome Is Not a Vascular Disease Weber, Boules, Fong, Abraham, Bena, El-Hayek, Kroh, Park* 39 patients (33 women, 6 men) underwent laparoscopic release of median arcuate ligament 4 conversions to open 3 SMA injury, 1 aortic injury 33/39 (85%) had relief of symptoms 30 patients had a post operative duplex 23 patent celiac artery 5 celiac stenosis no symptoms 2 occlusion one with continued symptoms Conclusion: Symptoms of Median Arcuate Ligament syndrome are not related to vascular compromise *Ann Vasc Surg 2016;30:

45 Median Arcuate Ligament Syndrome - Treatment Treatment: Endovascular treatment alone is ineffective Requires division of median arcuate ligament Bypass or angioplasty of residual celiac stenosis (after division of median arcuate ligament) Predictors of successful outcome: Female gender Weight loss > 20 lb. Absence of psychiatric/drug abuse history Celiac compression with post-stenotic dilation ± collateral vessels

46 Conclusions Mesenteric ischemia - acute and chronic - disease is relatively unusual diagnosis Acute mesenteric ischemia must be recognized early Recognize the different causes of acute mesenteric ischemia It appears that open revascularization continues to be standard of care Chronic mesenteric ischemia Can be addressed with endovascular approach some evidence to support covered stent in mesenteric vessels Operative approach: Antegrade bypass with prosthetic or vein Retrograde bypass with vein Mesenteric dissections are being observed more frequently Most can be treated with anticoagulation and follow up Median arcuate ligament syndrome likely not related to celiac stenosis/ischemia

47 Thank You

48 Review of Personal Experience 48 Mesenteric bypass procedures Exclude embolectomy, stent Prosthetic Bypass (antegrade) 15 patients 10 F; 5 M Average age 57.2 Vein Bypass (antegrade and retrograde) 23 patients 17 F; 6 M Average age

49 Mesenteric Bypass with Vein (n=23) Indication Ischemia: 17 Infection: 2 Trauma: 1 Aneurysm/dissection: 3 Vein used Deep vein: 13 GSV: 7 Both: 1 Unknown: 2 Inflow source Aorta: 7 Iliac: 14 (R:11, L: 2, unknown: 1) Interposition: 3 Distal target SMA: 21 SMA and hepatic: 1 SMA and IMA;

50 Prosthetic Bypass (n=15) Indication Ischemia: 14 Trauma: 1 Conduit used Prosthetic: 14 Prosthetic with GSV jump graft to celiac: 1 Inflow source Aorta Supra-celiac in all Distal Target SMA and celiac: 10 SMA:

51 Observations Vein bypass to mesenteric vessels is a good option Durable Deep vein is consistently of good quality Harvest of vein increases operative time Increases complications wound complications (hematoma, infection, lympho-cutaneous fistula) Appears that revascularization of one mesenteric vessel is satisfactory Vein is the preferred conduit in face of bowel infarction May not be possible with severe aorto-iliac occlusive disease Prosthetic bypass Supra-celiac aorta is generally free of atherosclerotic disease My preference is to create the proximal anastomosis, transect the graft limb to the celiac and create the anastomosis to the celiac (no tension), graft-graft anastomosis, other limb to the SMA

52 UK Surgical Treatment of Thrombotic Acute Intestinal Ischemia Retrospective review May 1993 July patients with thrombotic intestinal ischemia Average age: 60.9 years 20/58 (34%) were younger than 50 Excluded non-thrombotic causes (102 patients) Strangulated hernia Colon ischemia after aortic surgery Non-occlusive mesenteric ischemia Etiology of ischemia Arterial embolus 22 (38%) Arterial thrombosis 21 (36%) Venous thrombosis 15 (26%) Embolus 2 Arterial thrombosis 7 Venous thrombosis - 11 Endean, et al. Ann Surg, 2001

53 Patient Characteristics Arterial Embolism Arterial thrombosis Venous thrombosis Cardiac Disease No. % No. % No. % 20/ / /15 13 MI 6/ / /15 7 A fib 18/ /15 7 Valve disease 2/22 9 1/ CHF 10/ / Hyperlipidemia 4/ / Smoking 12/ / /15 47 HTN 11/ / /15 20 DM 4/ / /15 7 COPD 9/ / /15 7 PUD 5/ / /15 20 Cancer 5/ / /15 20 Mortality 13/ / /15 13

54 Arterial Embolus Most common presenting symptom: Acute onset of abdominal pain - 95% Nausea/vomiting 45% Male/Female: 10/12 (0.8) All but two patients had significant cardiac history Source of embolus: Cardiac (usually a fib) 21/22 (95%) Intra-aortic balloon pump 1/22 (5%) Operative intervention One patient refused surgery, all other patients had celiotomy: Celiotomy only - 5/22 (23%) Comfort care instituted Revascularization - 8/22 (36%) Bowel resection only - 7/22 (32%) Second look laparotomy 10 patients Average LOS: 13.6 days; 17.9 days if exclude comfort care patients

55 Arterial thrombosis Presenting symptoms Sudden onset of abdominal pain (13/21, 62%) Vomiting (13/21, 62%) Post prandial pain (4/21, 19%) Weight loss (2/21, 10%) Male/Female: 5/16 (0.3) Operative intervention All patients underwent surgical exploration Celiotomy only 8/21 (38%) Comfort care Revascularization 6/21 (29%) Bowel resection only 5/21 (24%) Second look laparotomy 5 patients Average LOS: 15.0 days; 22.9 days if exclude comfort care patients

56 Venous thrombosis Hypercoagualable work-up 33% found to have Protein C or S deficiency Male/Female: 11/4 (2.8) Non-operative treatment in 9/15 (60%) 2 patients had celiotomy only 4 patients had bowel resection No attempt at portal venous thrombectomy Two patients had infusion of thrombolytic via SMA Deaths: Patient 1 had pancreaticoduodenectomy Developed anastomotic leak Patient 2 diagnosis made 45 days after onset of symptoms Generalized peritonitis developed from bowel perforation Average LOS: 14.9 days

57 Conclusion from UK review Acute arterial mesenteric thrombotic event (embolus or thrombosis) tends to occur in older patients however up to 1/3 can be younger than 50 Mesenteric venous thrombosis tends to occur in younger patients Early diagnosis and intervention is key If exclude patients with extensive bowel necrosis (comfort care), mortality for arterial embolus: 47% (vs. 59%), arterial thrombosis: 38% (vs. 62%) Initial non-operative treatment for mesenteric venous thrombosis Evaluate for hypercoagulable conditions in mesenteric venous thrombosis

58 Other Mesenteric Conditions - Infection Bacterial endocarditis infecting SMA Excision of SMA Replace SMA with GSV Anastomose branches to GSV GSV

59 Comparison: History SMA embolus SMA thrombosis Venous thrombosis Age Age Women > Men + + +/- A Fib Prior MI Stroke Prior arterial embolus Prior symptoms of mesenteric ischemia Prior DVT/PE History of hypercoagulable disorder Pancreatitis/pancreatic cancer Adapted from Acosta and Björck, Br J Surg. 101; 2014

60 Comparison Physical Finding SMA embolus SMA thrombosis Venous thrombosis Sudden onset ++ +/- - Insidious onset Abdominal pain Vomiting Diarrhea Bloody stool + + +/- Synchronous embolization Adapted from Acosta and Björck, Br J Surg. 101; 2014

61 Case presentation 58-year-old man underwent Whipple Procedure for pancreatic cancer During procedure, the SMA was injured and ligated IMA stenosis treated with vein patch angioplasty Recovered from the surgery, then developed post-prandial pain Found to have SMA occlusion, severe stenosis of IMA, interrupted collaterals from celiac to SMA (s/p Whipple) Transferred to UK for mesenteric ischemia Underwent distal left external iliac to SMA bypass with deep vein About one year later, the patient was admitted with hypotension/sepsis CT scan demonstrated widely patent bypass graft

62 Determination of Bowel Viability Inspection Color Palpation of mesenteric pulses Peristalsis Doppler signal Anti-mesenteric border of bowel Distal mesenteric vessels Fluorescein Ultraviolet light Wood s lamp One shot evaluation Despite attempts to determine if bowel is viable, there remains areas that are questionable Second look laparotomy

63 Second Look Laparotomy A primary goal of treatment is preservation of bowel length to avoid short-gut syndrome After reperfusion: Clearly viable bowel Clearly infarcted bowel Indeterminate At initial operation, all infarcted bowel should be resected Ischemic/indeterminate bowel is left in place Return in hours Ischemic bowel should declare itself When a decision is made to do a second look, a second look MUST be done, even if the patient is doing well!

64 Management Algorithm Kim, J Vasc Surg 2014

65 Conclusion Incidentally found SMA dissection: Regular surveillance imaging (annual CTA) Progression of dissection or aneurysm dilation: Stent placement Acute abdominal pain with SMA dissection: Initial conservative management for most patients Suspicion of bowel infarction open surgery Evaluate bowel Revascularization (bypass, intimectomy, retrograde stent, antegrade stent) Compromised flow in SMA (severe narrowing of true lumen, persistent pain) Anticoagulation Stent Resolution of symptoms with conservative management Regular surveillance

66 Open Revascularization Considerations: Approach transperitoneal vs. retroperitoneal Graft orientation antegrade vs. retrograde Inflow source aorta vs. iliac Number of vessels reconstructed one, two, or three Conduit prosthetic vs. autogenous (vein)

67 Antegrade bypass Approach transperitoneal expose the aorta at the diaphragm Esophagus retracted to the left, left lobe of liver retracted to right Divide crus of diaphragm over the aorta Conduit prosthetic Polyester bifurcated graft (12 x 6 mm) Graft orientation antegrade Number of vessels reconstructed SMA and celiac Limb to SMA tunneled posterior or anterior to the pancreas SMA anastomosis end-side Celiac anastomosis end-end vs. end-side (common hepatic artery) Inflow source aorta Supra-celiac aorta tends to be free of atherosclerotic disease Partially occluding vs. occluding aortic clamp

68 Concerns with antegrade bypass Aortic exposure can be difficult Hemodynamic changes with supra-celiac aortic clamping Partially occluding clamp Proximal and distal aortic occlusion Potential for graft infection In presence of ischemic or infarcted bowel Standard teaching is to bypass to two arteries Typically Celiac and SMA Maintains bowel perfusion if one limb occludes

69 Approach transperitoneal Retrograde bypass Conduit prosthetic or vein GSV or deep vein less concern if in contact with bowel wall My choice Deep vein Consistently good size/quality of vein Durable conduit Graft orientation retrograde Number of vessels reconstructed SMA, ± celiac (i.e., hepatic) Inflow source aorta or iliac Aorta care must be taken or graft will kink Iliac - tunnel graft through mesentery Advantage no aortic cross clamp, ease of exposing iliac artery Disadvantage patient with severe aorto-iliac disease

70 Conclusions Angioplasty for chronic mesenteric disease is effective Covered stent may be associated with better outcome Less restenosis Less recurrence Less re-intervention Consider brachial approach Efficacy of embolic protection device Retrograde stent placement can be utilized