Direct Surgical Repair of Juxtarenal and Suprarenal Aneurysms of the Abdominal Aorta

Historical Background

The surgical management of abdominal aortic aneurysms was first pursued by direct aortic ligation as reported by Matas in 1923. Likewise, beginning in 1906, Halsted and Reid at the Johns Hopkins Hospital attempted to treat suprarenal aortic aneurysms in five patients by the placement of partially occlusive metal bands. Subsequent strategies included the induction of partial or complete thrombosis of aortic aneuryms by translumbar placement of intraluminal wires to increase wall thickness and reduce the risk of rupture. In 1949 Nissen wrapped Albert Einstein’s aortic aneurysm with cellophane, borrowing upon a technique described by Rea. Einstein eventually succumbed to rupture 6 years later. Complete resection of an abdominal aortic aneurysm and graft replacement was reported in 1951 by Dubost and colleagues, but this technique was often complicated by major bleeding from adherent nearby major venous structures. The modern technique of endoaneurysmorrhaphy with intraluminal graft placement was popularized by Creech in the 1960s and is the current approach for most aortic aneurysms, including juxtarenal abdominal aortic aneurysms (jAAAs) and suprarenal abdominal aortic aneurysms (sAAAs). The application of a left retroperitoneal approach to address extensive aneurysms of the abdominal aorta is credited to Williams.

Indications

The surgical repair of asymptomatic jAAAs and sAAAs carries a greater incidence of postoperative complications than the surgical repair of infrarenal aortic aneurysms. As a consequence, a 6-cm diameter is considered the threshold for repair of asymptomatic aneurysms. A slightly lower threshold (5.5 cm) may be considered for women, given a presumed increased risk for rupture. Symptomatic jAAAs and sAAAs should be repaired urgently.

Preoperative Preparation

Beta-blocker should be initiated before surgery with a target heart rate of less than 70 beats per minute.
Aspirin and statin therapy may reduce perioperative cardiovascular risk and should be maintained throughout the recovery period.
Thienopyridines should be halted 7 to 10 days before surgery because of risk of excessive bleeding, but should be resumed in the postoperative period if used as part of a dual antiplatelet regimen for patients who have received a drug-eluting coronary stent.
Double lumen endotracheal intubation is not necessary for left lung isolation for jAAA and sAAA repairs.
Intraoperative arterial line monitoring of blood pressure is recommended.
Intravenous access with large bore central lines should be established for rapid infusion, and pulmonary artery catheterization is mandatory for patients with cardiac dysfunction.
Intraoperative autotransfusion devices are preferred to return collected red blood cells from the aneurysmal sac and bleeding lumbar vessels.
Systemic normothermia should be maintained.
Perioperative prophylactic antibiotics should be given for 24 hours with intraoperative redosing for every 1500 mL blood loss.

Pitfalls and Danger Points

Intraoperative hemorrhage from a proximal anastomosis constructed to inhospitable aortic tissue or an iatrogenic venous injury to an unrecognized retroaortic left renal vein
Precipitous hemodynamic changes during aortic clamping and reperfusion leading to myocardial injury and renal dysfunction
Visceral ischemia from embolization during dissection and clamping of the proximal aorta or due to unrecognized stenosis of the visceral vessels
Colonic ischemia from interruption of the inferior mesenteric artery or collateral blood supply from the pelvis

Operative Strategy

Retroperitoneal or Transperitoneal Exposure

For a jAAA, a retroperitoneal or transperitoneal approach may be used. Randomized trials have not demonstrated major differences in outcomes for either approach. In general, a transperitoneal approach affords rapid access to the abdomen and ease of bilateral iliac exposure when large iliac aneurysms are present, but upper abdominal organs limits access to the visceral segment of the abdominal aorta. The left renal vein may be divided to facilitate suprarenal aortic clamping during a transperitoneal approach, but left renal dysfunction may ensue. The left retroperitoneal approach facilitates exposure of the upper abdominal aorta for cross clamping at or above the superior mesenteric artery or celiac axis—a strong advantage in a sAAA—but limits access to the right iliac artery and may require intraluminal right iliac control ( Box 24-1 ).

Box 24-1

RELATIVE INDICATIONS FOR RETROPERITONEAL EXPOSURE

“Hostile” abdomen secondary to multiple prior transperitoneal operations or presence of a stoma
Inflammatory aortic aneurysm
Horseshoe kidney
Need for suprarenal endarterectomy

Selection of Site for Proximal AORTIC Control

Preoperative computed tomography (CT) imaging is mandatory to determine the level of proximal aortic control. Features that suggest an appropriate clamp site include lack of significant calcification or mural thrombus, along with a normal aortic diameter. A jAAA implies the aneurysm extends to the lowest renal artery, necessitating aortic clamping above the renal arteries so that an anastomosis can be performed across the lower border of the renal arteries. In practice, a clamp may be placed across the jAAA neck if not overly burdened by atheroma, mural thrombus, or calcification to allow the surgeon to open the jAAA, evacuate the blood and mural thrombus, control lumbar vessels, with subsequent placement of the clamp above the renal arteries when performing the anastomosis. If feasible, such a strategy significantly reduces the period of renal ischemia.

For a sAAA, the aneurysm extends to involve varying portions of the renal artery origins and/or the visceral vessels. The segment of aorta between the celiac and the superior mesenteric artery may be more normal in caliber, but the presence of orificial disease near the superior mesenteric artery may preclude clamping in this area. If this visceral segment of the abdominal aorta is heavily diseased, the proximal clamp should be applied above the celiac axis to avoid embolization of debris into the visceral vessels. The supraceliac segment of aorta is also more easily exposed that the region between the superior mesenteric artery and celiac axis.

Operative Technique

Control of the Suprarenal Aorta

The suprarenal aorta can be approached from either a transperitoneal or retroperitoneal exposure. In the transperitoneal exposure, the duodenum is mobilized to the right with the root of the mesentery. The retroperitoneal tissues along the lower border of the pancreas are opened, and the inferior mesenteric vein should be divided from its confluence onto the splenic vein to allow a static retraction device to reflect the pancreas cephalad. The left renal vein is appreciated coursing across the aorta and overlying the renal artery origins. By sacrificing the lumbar and gonadal branches to the left renal vein seen just left of the aorta, the left renal vein can be retracted to expose the suprarenal aorta for clamp application.

Control of the Supraceliac Aorta

In the retroperitoneal exposure of the jAAA or sAAA, the left-sided abdominal structures are reflected medially. The left retroperitoneal space is developed cephalad, and the spleen is displaced medially until the left crural fibers of the diaphragm are appreciated. The suprarenal aorta is covered by the left crural diaphragmatic muscle and a layer of thick fascia, which is continuous with the pleura. Both layers can be divided with electrocautery after a clamp or index finger is insinuated beneath these layers to develop a surgical plane along the left side of the aorta. Short, direct arteriolar perforators to the crus are rarely encountered during this maneuver, but if encountered, direct suture repair of the aortic wall with pledgeted 4-0 polypropylene sutures placed in horizontal-mattress fashion may be required. Sharp dissection is used to dissect the retroperitoneal tissues from the region surrounding the origins of the visceral vessel to allow secure clamping, and reduce bleeding as well as embolization during proximal aortic clamping. The anterior and posterior tissues just above the celiac axis are easily mobilized to allow proximal aortic control.

Retroperitoneal Exposure

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