Overview
Definition:
Retroperitoneal iliac artery exposure refers to surgical access to the iliac arteries (common, internal, and external) via an incision made in the retroperitoneum, posterior to the peritoneum
This approach is crucial for managing a range of vascular pathologies affecting the pelvic and lower limb vasculature.
Epidemiology:
Iliac artery aneurysms and occlusive disease are significant contributors to vascular morbidity
Aneurysms typically affect the common iliac artery, often in conjunction with abdominal aortic aneurysms
Atherosclerotic occlusive disease commonly affects the distal common and external iliac arteries, leading to critical limb ischemia.
Clinical Significance:
Accurate and safe exposure of the iliac arteries is fundamental for various surgical interventions including endovascular repair, open aneurysm resection, arterial bypass grafting, thromboendarterectomy, and management of trauma
Proficiency in this exposure is vital for surgical residents preparing for DNB and NEET SS exams and for ensuring optimal patient outcomes in vascular surgery.
Indications
Aneurysm Repair:
Repair of common iliac artery aneurysms, external iliac artery aneurysms, or concomitant iliac artery aneurysms with abdominal aortic aneurysms.
Occlusive Disease:
Treatment of severe aortoiliac occlusive disease necessitating bypass grafting or endarterectomy.
Embolism Thrombosis:
Management of acute or chronic iliac artery thrombosis or emboli causing limb ischemia.
Trauma:
Control of hemorrhage from iliac artery injury due to penetrating or blunt trauma.
Other Pathologies:
Exposure for aberrant vessel anatomy, arteriovenous fistulas, or tumors involving the iliac arteries.
Preoperative Preparation
Patient Assessment:
Thorough cardiovascular assessment, including cardiac function and comorbidities
Assessment of renal function and electrolyte balance.
Imaging Studies:
Preoperative imaging (CTA, MRA, or conventional angiography) is essential for defining the extent of disease, anatomical variations, and relationship to surrounding structures.
Medical Optimization:
Optimization of anticoagulation status (if applicable)
Management of hypertension and diabetes
Smoking cessation counseling.
Anesthesia Considerations:
General anesthesia is typically preferred
Epidural anesthesia may be considered in select cases
Careful hemodynamic monitoring is paramount.
Bowel Preparation:
Standard bowel preparation is often performed, although not always mandatory depending on the specific surgical approach.
Surgical Approach
Incision Choice:
The most common incision is a midline laparotomy extending from the xiphoid process to the pubic symphysis, allowing access to the infrarenal aorta and bifurcation
A left paramedian incision is also frequently used
For isolated distal iliac artery pathology, a lower abdominal transverse or oblique incision (e.g., Gibson incision) may be employed.
Retroperitoneal Dissection:
After opening the peritoneum, mobilization of the colon, small bowel, and spleen/mesentery is performed to gain access to the retroperitoneal space
The aorta and inferior vena cava are identified, and careful dissection proceeds inferiorly towards the iliac vessels.
Vessel Identification:
The infrarenal aorta, superior hypogastric plexus, common iliac arteries, internal iliac (hypogastric) arteries, and external iliac arteries are meticulously identified
Dissection must carefully avoid injury to adjacent nerves and lymphatic vessels.
Control Of Vessels:
Proximal and distal control of the target iliac artery is achieved using vascular tapes or soft vascular clamps
For complex dissections or significant inflammation, careful mobilization and identification of branching vessels are critical.
Exposure Variations:
Exposure of the common iliac artery is typically achieved by dissecting off the psoas muscle
For the external iliac artery, dissection continues along the pelvic brim
Access to the internal iliac artery may require mobilization of the ureter and dissection posterior to the common iliac vein.
Management Techniques
Endovascular Repair:
Stent grafts are deployed via transfemoral access, often requiring proximal landing zones in the common iliac arteries
This approach minimizes retroperitoneal dissection but requires detailed anatomical assessment.
Open Aneurysm Repair:
Resection of the aneurysm sac and reconstruction with a prosthetic graft
This involves proximal and distal control of the common iliac arteries, followed by graft anastomosis.
Bypass Grafting:
For aortoiliac occlusive disease, bypass grafts (e.g., aortobifemoral) are fashioned with anastomoses to the common or external iliac arteries
Endarterectomy may also be performed for localized occlusive lesions.
Thromboembolectomy:
Open surgical removal of thrombus or emboli from the iliac arteries, often performed as an emergency procedure.
Trauma Management:
Direct repair, ligation, or interposition grafting of injured iliac arteries
Hemostasis is paramount.
Postoperative Care
Hemodynamic Monitoring:
Close monitoring of blood pressure, heart rate, and fluid balance is crucial
Management of hypotension or hypertension.
Pain Management:
Adequate analgesia, often with patient-controlled analgesia (PCA), is required
Epidural analgesia may be beneficial for open procedures.
Wound Care:
Routine wound care, monitoring for signs of infection or dehiscence
Early mobilization is encouraged to prevent deep vein thrombosis and pulmonary complications.
Anticoagulation:
Postoperative anticoagulation or antiplatelet therapy is administered based on the specific pathology and surgical procedure performed, following established guidelines.
Renal Function Monitoring:
Monitoring of urine output and serum creatinine levels, especially in patients with pre-existing renal impairment or those undergoing prolonged aortic clamping.
Complications
Early Complications:
Hemorrhage from the surgical site or anastomotic leak
Ischemia or thrombosis of limb or pelvic organs
Injury to adjacent structures (ureter, bowel, nerves, vena cava)
Deep vein thrombosis
Pulmonary embolism
Myocardial infarction.
Late Complications:
Graft infection
Pseudoaneurysm formation at anastomoses
Restenosis or occlusion of the graft
Chronic limb ischemia
Incisional hernia
Pelvic congestion syndrome.
Prevention Strategies:
Meticulous surgical technique with careful dissection
Preoperative imaging to identify anatomical hazards
Judicious use of vascular clamps
Appropriate perioperative anticoagulation and antibiotic prophylaxis
Aggressive postoperative mobilization and prophylaxis against DVT.
Key Points
Exam Focus:
Understanding the anatomical landmarks for iliac artery exposure is critical
Differentiate between common, internal, and external iliac artery origins and their relationships to surrounding structures like the ureter and hypogastric plexus.
Clinical Pearls:
Always identify and protect the ureter during dissection
Be aware of aberrant anatomy
Proximal control of the common iliac artery should ideally be achieved above the bifurcation
In cases of severe inflammation or calcification, careful mobilization is key to avoid avulsion.
Common Mistakes:
Inadequate proximal control leading to uncontrolled hemorrhage
Injury to the vena cava or its tributaries
Iatrogenic ureteral injury
Insufficient exposure of the distal external iliac artery
Failure to identify and control the internal iliac artery when necessary for aneurysm exclusion.