Perioperative management - Iliacomesenteric venous bypass in superior mesenteric artery occlusion—Vascular Surgery

• Intestinal angina due to short segmental stenosis of the superior mesenteric artery (SMA) close to its origin or occlusion due to inadequate collateral blood supply via the celiac trunk
• Lack of indication for interventional treatment, e.g., in long stenosis at the origin stenosis/occlusion of the SMA).
• Failure of interventional management

Video clip: SMA occlusion close to its origin with occlusion of the celiac trunk

Grade of ischemia and general indication for surgery

• long-distance and multifocal stenoses of the SMA > 6 cm usualy do not lend themselves to open repair
• Multisegment occlusive processes of the SMA, e.g. in thrombangitis obliterans (Winiwarter-Buerger disease) or lupus erythematosus
• ASA IV
• COPD Cold IV

Key aspects first:

1. Chronic intestinal ischemia syndromes: Only diagnostic imaging yields useful insights!

2. Usually there are multiple (vascular) comorbidities -> detailed examination by vascular surgeons and angiologists.

3. Patient should undergo work-up to identify other abdominal diseases, especially to rule out malignancies.

4. Delayed diagnosis > 12 months because differential diagnosis included the disease too late.

Medical history

Typical triad in malperfusion of the SMA:

• postprandial abdominal pain starting shortly (about 20 min) after food intake and subsiding after 3-4 hours (intestinal angina)
• reactive restriction on food intake -> weight loss, muscle atrophy, asthenia ("small-meal-syndrome")

Absence of weight loss does not rule out the diagnosis!

Ischemia of the celiac trunk distribution site results in nausea, vomiting, and meteorism; constipation is more likely to result from inferior mesenteric artery disease.

Duplex ultrasonography for assessment of the intestinal vessels

• Stenosis typically at the origin
• Increased flow rate—flow rates greater than 200 cm/s are considered pathognomonic for high-grade stenosis—as well as turbulent flow

CT angiography or MR angiography

• with image reconstruction

digital subtraction angiography of the intestinal arteries in 2 planes

• when planning an intervention

Abdominal ultrasonography

(Exercise) ECG

Chest X-ray

Laboratory panels

• Blood count, electrolytes, coagulation, renal retention parameters, blood lipids

Staged diagnostic approach to intestinal ischemia

• Ultrasound assessment of whether an autologous great saphenous vein is available as a bypass (possibly synthetic graft)
• Identify blood group, provide for packed RBCs, if needed
• Enema
• Indwelling urinary catheter

General surgical risks

• Major bleeding, blood transfusions, transmission of hepatitis/HIV through allogeneic blood transfusions
• Allergy/intolerance
• Wound infection
• Thrombosis/embolism
• Skin/vascular/nerve damage, e.g., due to patient positioning
• Keloid

Risks special to this procedure

• Incisional hernia
• Abdominal adhesions, ileus
• intraoperative peripheral embolism in iliac/leg arteries -> surgical intervention, in case of ischemic leg including amputation
• Massive infection → bleeding, peritonitis, sepsis; possible reoperation with explantation of the vascular graft
• Injury to neighboring organs (ureter, bladder, bowel, liver, spleen); intestinal stoma
• Impaired perfusion or nerve injury of the spinal cord (paresis, erectile dysfunction)
• In case of autologous vein bypass: Secondary bleeding, infection, keloid
• Intraoperative angiography: Contrast agent → renal failure
• Bypass infection/stenosis → impaired perfusion of the affected organs, reoperation
• Impaired intestinal perfusion → defecation disorder, malabsorption, ischemic colitis → resection, possibly colostomy