Comparison of supramesenteric aortic cross-clamping with supraceliac aortic cross-clamping for aortic reconstruction

Cross-clamp location and perioperative outcomes after open infrarenal abdominal aortic aneurysm repair: A Vascular Quality Initiative® review

OBJECTIVES

By analyzing national Vascular Quality Initiative (VQI) data for patients undergoing open infrarenal abdominal aortic aneurysms (AAA) repair, we sought to better characterize the effects of different suprarenal clamping positions on postoperative outcomes.

METHODS

We performed a retrospective analysis of a prospectively collected national VQI database for all open infrarenal AAA repairs performed between 2003 and 2017. Patients were initially divided into proximal (above 1 renal, above 2 renals, and supraceliac) and infrarenal clamp groups. Patients were then subdivided into those who underwent surgery between 2003-2010 and those who had surgery between 2011-2017. Univariate followed by multivariate analyses were done to compare the baseline characteristics, preoperative, intraoperative, and postoperative outcomes between the two groups.

RESULTS

During the study period, 9068 open AAA repairs were recorded in the VQI; of these, 5043 met the inclusion criteria. Aortic clamp level was infrarenal in 59% (N = 2975), above 1 renal in 15% (N = 735), above both renals in 21% (N = 1053), and supraceliac in 5% (N = 280). The average age was 69 years, and males comprised 73% (N = 3701) of the cohort. The overall 30-day mortality for the entire study group was 2.7%. On univariate analysis, patients who underwent proximal clamping had significantly higher 30-day mortality than those undergoing infrarenal clamping (3.7 vs 2.0%, p < 0.001). After adjusting for preoperative and intraoperative variables, this difference became nonsignificant. On multivariate analysis, clamping above both renals or the celiac artery was associated with an increased occurrence of postoperative myocardial infarction (odds ratio = 1.44, p = 0.037 and odds ratio = 1.78, p = 0.023, respectively). All proximal clamp positions were associated with a significant increase in the incidence of AKI and renal failure requiring dialysis. There was no significant difference when looking at overall survival times comparing the suprarenal and infrarenal clamp position groups (p = 0.1). Patients who underwent surgery in the latter half of the study period had longer intraoperative renal ischemia time, increased in estimated blood loss, and longer total procedure time.

CONCLUSIONS

Suprarenal clamping, at any level, was associated with an increased risk of AKI and renal replacement therapy. Clamping above both renal and celiac arteries was associated with increased cardiac morbidity. Perioperative and long-term mortality was unaffected by clamp level. Patients operating in the latter half of the study had increased estimated blood loss, renal ischemia time, and operative time, which may reflect decreased training in open AAA repair. During open AAA repair, the proximal clamp site should be chosen based on anatomic considerations and not a perceived perioperative mortality benefit. Proximal aortic clamping should always be performed at the safest, distal-most level to reduce cardiac morbidity and the risk of postoperative dialysis.

Merits of and Technical Tips for Supra-Mesenteric Aortic Cross Clamping

Supra-celiac aortic cross clamping is often utilized during aortic reconstruction for aneurysmal/occlusive disease involving the pararenal aorta. However, this may be accompanied a myriad of complications related to hemodynamic disturbances, cardiopulmonary compromise and hepatic ischemia. Supra-mesenteric aortic cross clamping may be an excellent option in selected patients with suitable anatomy to minimize or avoid these complications. Herein, the merits of and technical tips for supra-mesenteric aortic cross clamping are discussed.

Anatomical Considerations and Open Surgery to Treat Juxtarenal Abdominal Aortic Aneurysms

Introduction:

Historically, the open approach to the abdominal aorta has been transperitoneal (TP). In comparison, a retroperitoneal (RP) incision exposes the lateral wall of the suprarenal aorta for clamp application and midline structures such as the duodenum and pancreas are not encountered. Proximal clamp position for open repair of juxtarenal abdominal aortic aneurysm (JR-AAA) is suprarenal, supra-superior mesenteric, or supraceliac. While RP and TP approaches have previously been compared for physiological reasons, there are currently no randomized controlled trials comparing these methods from an anatomical perspective.

Aims:

The primary aim is to examine the evidence for adopting an RP approach for JR-AAA and compare it with TP approach from an anatomical perspective. The secondary aim is to assess optimum proximal clamp position and its effect on renal function and mortality for the 2 approaches.

Methods/Design:

Literature was reviewed searching databases Medline and Embase for studies on clamp positioning in JR-AAA repair using a TP or RP approach, up to December 2017.

Conclusions:

There is no clear evidence for the optimum cross-clamp position for open repair of JR-AAAs. More proximal clamps provide adequate operative space with the possible downside of increased afterload leading to visceral and renal ischemia. Clamps placed inferior to the superior mesenteric artery allow continued bowel and hepatic perfusion with the potential to cause trauma to the adjacent aortic branches during application. As far as the optimum approach is concerned, many series show a strong trend for RP as a more proximal clamp is required. Significant numbers develop renal failure after JR-AAA repair, with most recovering fully irrespective of the clamp position.