Complications - Aortoiliac TEA (thromboendarterectomy) in bilateral stage IIb peripheral arterial (occlusive) disease (PAD) - Vascular surgery

Bleeding

• injured iliac veins -> compression of run-in and run-off, suture
• Arterial bleeding -> suture

Injury to the inferior mesenteric artery in poor collaterals

• Revascularization due to impending ischemic colitis

Iatrogenic bowel lesion

• Suture

1. Early course (≤ 30 days postoperatively)

Secondary bleeding, hematoma

• Causes: technical errors such as suture line failure; slipped off ligatures; inadequate hemostasis; also needle track bleeding; iatrogenic vascular lesions; surgery under concomitant antiplatelets
• Management: emergency surgery in active and hemodynamically significant bleeding; liberal indication for evacuation of hematomas as a breeding ground for infection and also possible cause of compression of other structures (compartment syndrome).
• Prevention: careful dissection, subtle hemostasis

Thrombosis/embolism of the revascularization with early occlusion

• Cause: mostly technical errors
• Diagnosis: color- flow Doppler ultrasonography, possibly CT-angiography
• Management: revision surgery, possibly embolectomy; check coagulation status
• Prevention: careful atraumatic, anatomically correct surgical technique

Wound infection

• Diagnosis: Local findings, lab panels, fever
• Management: if unavoidable, reopen the wound; swab; debridement; possibly NPWT, AST-specific antibiotics
• Caution: In the presence of alloplastic material (vascular graft), graft infection could always be the root cause; conversely, wound infection could also spread to the alloplastic material!
• Prevention: careful atraumatic, anatomically correct surgical technique, subtle hemostasis, avoidance of injury to the lymphatics

Compartment syndrome

• Cause: Reperfusion after complete or incomplete ischemia results in damage to the capillary membrane with increased permeability and soft tissue edema, increasing the pressure in muscle compartments with tissue death.
• Clinical signs: see red flags
• Diagnostic work-up: Clinical picture, see Red Flags; assess objectively by intracompartmental pressure measurement (borderline pressure between 30 and 50 mmHg over 6 hours, as well as pressure readings above 50 mmHg, are pathologic).
• Management: immediate dermatofasciotomy with complete longitudinal fascia cleavage in all muscle compartments, followed later by dermatotraction via alloplastic skin graft or NPWT, split-thickness skin graft.

Lymphatic fistula, lymphocele

• Risk: Access via the inguinal region predestined for injury to lymphatics
• Diagnosis: clinical local findings
• Treatment: nonsurgical management of lymphoceles, bearing in mind the risk of infection; lymphatic fistulas should be drained long-term without suction, or, after ruling out infection, by injection of fibrin glue or revision surgery with ligation (methylene blue, surgical loupes), very rarely by plastic surgery
• Prevention: Protect the lymphatics by lateral approach, sweep lymphatic tissue anteromediad

Ischemia of the colon and pelvic organs

• Cause: ligation/elimination of the inferior mesenteric artery, which is why the sigmoid colon (86%) and descending colon (60%) are most frequently affected
• Clinical signs: bloody stools; diarrhea; abdominal pain; peritonitis.
• Diagnostic work-up: Rectosigmoidoscopy, possibly colonoscopy (Caution: increased risk of perforation!); laboratory panels are non-specific!
• Management: nonsurgical (watchful waiting) only in case of transient mucosal ischemia/grade A, otherwise bowel resection depending on location, possibly Hartmann procedure.
• Prevention: during primary surgery broad indication for reimplantation of the inferior mesenteric artery in a vascular graft, if clamping results in intraoperative signs of ischemia

Urinary or fecal incontinence, gluteal claudication and even necrosis of the buttocks, and sexual dysfunction may result from impairment of the branches of the internal iliac arteries.

Spinal ischemia and paraplegia ("ischemic spinal cord injury" - SCI)

• Cause: Reduced blood flow to the spinal cord due to open aortic grafting or endovascular stenting of arteries relevant to the spinal cord in combination with other risk factors such as perioperative hypotension, major blood loss/anemia; especially in thoracic/thoracoabdominal procedures.

• If at least two spinal perfusion territories are compromised, the likelihood of spinal ischemia increases.

• Clinical signs: range from minor transient sensory impairments through functional disorders of the continence organs to complete paraplegia with lifelong bed confinement and need for nursing care.

• Management:  Increase spinal perfusion pressure, e.g. ,increase the mean arterial pressure with medication and insert a CSF shunt to reduce the arterial perfusion backpressure in the CSF spaces
• Prevention: Avoid intraoperative and postoperative hypotension and, after segmental artery occlusion, maintain a mean arterial pressure of 80-90 mm Hg for at least 48 h; insert a prophylactic spinal CSF shunt if at least two territories of spinal blood flow (see above) are impaired and cannot be reopened by revascularizing measures (e.g., carotid artery-subclavian artery bypass); maintain adequate central venous saturation (ScvO2) of ≥70% perioperatively and intraoperative central venous pressure (CVP) of ≤10 mmHg; keep hemoglobin level ≥ 8 mg/dl and intraoperative blood loss as low as possible; cell saver; prompt postoperative extubation in order to ascertain neurological status; close follow-up.

Systemic complications

• For instance, acute coronary syndrome; myocardial infarction; pneumonia; cerebrovascular events; kidney failure -> adequate multidisciplinary management

Late course (> 30 days postoperatively)

Pseudoaneurysm

• Cause: bleeding into the surrounding tissue with formation of an extravascular, pulsating hematoma after vessel puncture, in the vicinity of anatosmoses and patch plasties, also due to infection/broken sutures
• Diagnostics: color flow Doppler ultrasonography (circulating perivascular blood flow, evidence of aneurysm neck with "to and fro" blood flow pattern)
• Management: watchful waiting in small, asymptomatic aneurysms, otherwise endovascular or open repair

Stenosis of arterial revascularization with late occlusion

• See early occlusion

Suture aneurysm

• Cause: Suture breakage; deep aortic anastomosis; turbulent blood flow; thromboendarterectomy; infection; graft degeneration
• Clinical signs: depending on location, e.g., pulsating inguinal tumor, also hemorrhagic shock in rupture
• Diagnostics: color-flow Doppler ultrasonography, possibly CT-angiography
• Management: revision surgery, endovascular intervention.

Sexual dysfunction (in men)

• Cause: neurogenic due to intraoperative injury of the hypogastric plexus, which is located anterior to the abdominal aorta or aortic bifurcation and the iliac arteries and conducts the signals for erection and ejaculation; vascular due to microemboli entering the penile arteries during cross-clamping of the aorta; or unilateral/bilateral interruption of the hypogastric artery during repair of concomitant iliac artery aneurysms 
• Clinical signs: transient and irreversible erectile and ejaculatory dysfunction
• Prevention: spare the hypogastric plexus by anterolateral right aortotomy and appropriate placement and tunneling of the left limb of an aorto(bi)iliac or femoral bypass; alternatively, primarily retroperitoneal left access; preserve antegrade perfusion of the internal iliac artery at least on one side, preferably bilaterally

Persistent lymphedema

• Manual lymphatic drainage and in case of adequate arterial perfusion (!) consistent compression treatment

Incisional hernia

• Surgical treatment according to the current standards in hernia surgery (sublay or onlay mesh or laparoscopic hernia repair with intraperitoneal onlay mesh)