Management of juxtarenal aortic aneurysms and occlusive disease with preferential suprarenal clamping via a midline transperitoneal incision: technique and results

Surgical management of juxtarenal aortic (JR-Ao) aneurysms and occlusive disease may include supraceliac aortic clamping, a retroperitoneal approach, or medial visceral rotation. The authors report their results using preferential direct suprarenal aortic clamping via a midline transperitoneal incision. Between July 1, 1992, and July 31, 2001, they treated 58 patients with JR-Ao disease (44 aneurysmal, 14 occlusive) via a midline incision without medial visceral rotation. Preferential suprarenal aortic clamping was used in 53 cases (42 proximal to both renal arteries, 11 proximal to the left renal artery only) and supraceliac or supramesenteric clamping in 5 cases when there was insufficient space for an aortic clamp between the superior mesenteric artery and renal arteries. This strategy avoided mesenteric ischemia associated with supraceliac clamping in the majority of cases and afforded better exposure of the right renal artery than obtainable with a left retroperitoneal approach or medial visceral rotation. Eleven patients underwent concomitant renal revascularization. Critical adjuncts included the following: (1) selective left renal vein (LRV) division if the vein stump pressure was < 35 mm Hg (suggesting sufficient renal venous collaterals existed), (2) bilateral renal artery occlusion during aortic clamping to prevent thromboembolism, (3) flushing of aortic debris before restoring renal perfusion, and (4) routine administration of perioperative intravenous mannitol and renal-dose dopamine. Patients with type IV thoracoabdominal aneurysms, ruptured aneurysms, or JR-Ao disease approached via a retroperitoneal incision (severely obese patients, re-do aortic surgery) were excluded. No patients died or required dialysis during their hospital stay. The LRV was divided in 12 (21%) cases and reanastomosed in 2 cases (elevated stump pressures). The average suprarenal clamp time was 26 minutes (range, 10-60). Postoperative serum creatinine remained > 0.5 ng/dL above baseline in 3 (5%) patients. These results support suprarenal aortic clamping with a midline transperitoneal incision as the optimal strategy for treating juxtarenal aortic aneurysms and occlusive disease. The authors believe that selective left renal vein division enhances juxtarenal aortic exposure, and routine administration of renal protective agents, along with occlusion of both renal arteries during suprarenal aortic clamping, are critical adjuncts in performing these operations.     

Results of supraceliac aortic clamping in the difficult elective resection of infrarenal abdominal aortic aneurysm

We have used clamping of the aorta above the celiac axis (SC) in 30 of 431 elective resections of infrainguinal abdominal aortic aneurysms (AAA) during the past five years as an alternative to a difficult aortic cuff dissection. The results of SC clamping in these 30 patients are compared with the results of 379 routine aneurysm resections with infrarenal (IR) clamping and 22 additional aneurysm resections where the clamp was placed immediately above the renal arteries. These difficult cuff dissections occurred in 12 patients with inflammatory AAA, in 11 patients with juxtarenal AAA, and in seven patients with recurrent or noninfected false AAA of the proximal cuff. Patients with ruptured or suprarenal aneurysms and those undergoing combined operation for a visceral ischemic syndrome and an aneurysm were excluded from this study. Patients with SC clamping had similar operative mortality rates, comparable renal function, and frequency of cardiac events as patients with IR clamping. Blood loss was slightly higher in the SC group (p = 0.07) and serum aspartate amino transferase (AST) levels were three times higher than in the IR group; however, this was of no clinical significance. In contrast, those 22 patients whose aortas were clamped immediately above the renal arteries (AR) had higher perioperative mortality rates (2% IR, 3% SC vs 32% AR) and a higher incidence of kidney failure requiring dialysis (1% IR, 3% SC vs 23% AR). The mean values of serum creatinine and blood urea nitrogen were also significantly higher in the AR group when compared with both the IR and the SC groups (IR: 25 and 1.5 mg/dl, respectively; SC: 27 and 1.8 mg/dl; AR: 41 and 3.5 mg/dl). The single most important risk factor accounting for the differences between clamping above the celiac artery and clamping above the renal arteries was the presence of atherosclerotic debris in the nonaneurysmal, juxtarenal aortic segment. Clamping the aorta with juxtarenal atherosclerosis caused either atheroembolization to kidneys, legs, and intestine or injury to the aorta, renal arteries, or both; it was the cause of morbidity in all five cases of kidney failure requiring dialysis and accounted for all seven of the deaths in the AR group. SC clamping does not add risk to the patient undergoing resection of an infrarenal AAA and is the preferred method of achieving proximal control of the infrarenal aorta when a a hazardous cuff dissection is likely.(ABSTRACT TRUNCATED AT 400 WORDS)     

Early prognostic factors of the surgery of aneurysms of the abdominal aorta with renal artery clamping]

The aneurysms of the abdominal aorta requiring suprarenal clamping are rare. Suprarenal clamping was required for only 43 of 544 aneurysms operated electively from 1981 to 1989. Twenty-five patients had a juxtarenal aneurysm, without any normal aortic segment under the renal arteries, and suprarenal clamping was therefore necessary while the upper anastomosis was being established (group I). Eighteen patients had an aneurysm enclosing the root of at least one renal artery (group II). Several prognostic factors have been assessed: patient's age, presence of preoperative renal insufficiency, of arterial hypertension or of coronary insufficiency, and revascularization method. Five patients died. Four of them belonged to group II and were over 75 years old. All presented with a preoperative renal insufficiency. Two of these deaths were caused by mesenteric infarction. Four cases of regressive postoperative renal insufficiency were observed in patients for whom renal clamping had lasted longer than 45 minutes. This study allowed outlining three prognostic factors: the patient's age, preoperative renal insufficiency, a period of renal ischemia exceeding 40 minutes. On the other hand, the severity of hypertension had no predictive value. Coronary insufficiency requires a strict hemodynamic surveillance, but is not a contraindication for revascularization.     

Management of juxtarenal aortic occlusions: Technique for suprarenal clamp placement

Atherosclerotic occlusion of the entire infrarenal abdominal aorta can produce gangrene, rest pain or claudication and can progress to involve the renal artery origins. Features of the operative technique for treating these juxtarenal aortic occlusions include self-retaining retraction, mobilization of the left renal vein with division of all non-renal branches, exposure of the suprarenal aorta and renal arteries by division between clamps of the surrounding paraaortic fibroareolar tissue and fat, sharp division of crural attachments to the aorta, control of the two renal arteries with doubled vessel loops and then direct vertical clamping of the suprarenal aorta. Through an arteriotomy below the renal arteries, 2–4 cm of pararenal aorta are cleared of thrombus and atherosclerotic debris under direct vision. After transfer of the suprarenal clamp to an infrarenal position, conventional aortobifemoral bypass is then performed. In a series of 18 patients with juxtarenal aortic occlusion managed by this technique, suprarenal clamp time ranged from 4 to 25 minutes (mean, 13 minutes). There was no morbidity from renal failure or emboli and no mortality. This technique allows for deliberate, careful disobliteration of the pararenal and infrarenal aorta and minimizes the risk of renal embolization.     

Factors affecting outcomes of open surgical repair of pararenal aortic aneurysms: a 10-year experience

PURPOSE: Few large series document surgical outcomes for patients with pararenal abdominal aortic aneurysms (PAAAs), defined as aneurysms including the juxtarenal aorta or renal artery origins that require suprarenal aortic clamping. No standard endovascular alternatives presently exist; however, future endovascular branch graft repairs ultimately must be compared with the gold standard of open repair. To this end, we present a 10-year experience. METHODS: Between 1993 and 2003, 3058 AAAs were repaired. Perioperative variables, morbidity, and mortality were retrospectively assessed. Renal insufficiency was defined as a rise in the concentration of serum creatinine by > or = 0.5 mg/dL. Factors predicting complications were identified by multivariate analyses. Morbidity and 30-day mortality were evaluated with multiple logistic regression analysis. RESULTS: Of a total of 3058 AAA repairs performed, 247 were PAAAs (8%). Mean renal ischemia time was 23 minutes (range, 5 to 60 minutes). Cardiac complications occurred in 32 patients (13%), pulmonary complications in 38 (16%), and renal insufficiency in 54 (22%). Multivariate analysis associated myocardial infarction with advanced age (P = .01) and abnormal preoperative serum creatinine (>1.5 mg/dL) (P = .08). Pulmonary complications were associated with advanced age (P = .03), renal artery bypass (P = .02), increased mesenteric ischemic time (P = .01), suprarenal aneurysm repair (P < .0008), and left renal vein division (P = .01). Renal insufficiency was associated with increased mesenteric ischemic time (P = .001), supravisceral clamping (P = .04), left renal vein division (P = .04), and renal artery bypass (P = .0002), but not renal artery reimplantation or endarterectomy. New dialysis was required in 3.7% (9/242). Abnormal preoperative serum creatinine (>1.5 mg/dL) was predictive of the need for postoperative dialysis (10% vs 2%; P = .04). Patients with normal preoperative renal function had improved recovery (93% vs 36%; P = .0002). The 30-day surgical mortality was 2.5% (6/247) but was not predicted by any factors, and in-hospital mortality was 2.8% (7/247). Median intensive care and hospital stays were 3 and 9 days, respectively, and longer stays were associated with age at surgery (P = .007 and P = .0002, respectively) and any postoperative complication. CONCLUSIONS: PAAA repair can be performed with low mortality. Renal insufficiency is the most frequent complication, but avoiding renal artery bypass, prolonged mesenteric ischemia time, or left renal vein transection may improve results.     

Suprarenal clamping is a safe method of aortic control when infrarenal clamping is not desirable

We evaluated the safety of suprarenal aortic clamping in patients with abdominal aortic aneurysm (AAA) treated by open aortic replacement by retrospectively reviewing all patients who underwent elective AAA replacement at a university hospital from 1993 until 2003. We reviewed 249 patient charts and divided them into three groups according to the clamp location during aortic replacement: group 1, infrarenal clamp group (n = 185); group 2, suprarenal clamp group (n = 52); and group 3, supraceliac clamp group (n = 12). Groups 1 and 2 were compared with respect to risk factors, intraoperative events, and postoperative events. Statistical analysis was done using Wilcoxon's rank-sum test, chi-squared test, and Fisher's exact test. Risk factors were comparable in groups 1 and 2 except for weight, which was higher in group 1. Intraoperative urine output, hypotensive episodes, and use of renal protective drugs were comparable in the two groups. Operation time, blood loss, and use of IV fluids were all significantly higher in group 2, while total aortic clamp time was higher in group 1. Postoperative events were comparable except for postoperative peak creatinine, intensive care unit length of stay, and postoperative length of stay, which were higher in group 2; however, discharge creatinine was comparable without a significant difference. Suprarenal clamping is a safe method of aortic control during open AAA replacement surgery. The selection of clamping site should be individualized according to the intraoperative anatomy. Supraceliac clamping is not necessarily the preferable method of aortic control when the infrarenal location is not suitable for clamping.     

Open Repair of Pararenal Aortic Aneurysms: Operative Management, Early Results, and Risk Factor Analysis

Surgical treatment of pararenal aortic aneurysms, if compared to open surgical repair of infrarenal aneurysms, is technically more demanding and characterized by problems related to organ ischemia. To better define challenges, risks, and results, we analyzed our experience with the treatment of pararenal aortic aneurysms. Between January 1993 and March 2005, 119 consecutive patients underwent surgery for pararenal aneurysms at our institution. A prospective analysis of results was performed. According to their localization, we treated 85 juxtarenal aneurysms and 34 suprarenal aneurysms. One hundred and three patients underwent primary repair of an atherosclerotic aneurysm, four patients underwent surgical repair of an anastomotic pseudoaneurysm, and eight patients underwent correction of an aneurysm of the pararenal aorta proximal to a previous infrarenal anastomosis. Four patients underwent emergency operation for a ruptured aneurysm. In the juxtarenal aneurysm group, the 30-day mortality rate was 4.7% (4/85) including three patients with ruptured aneurysm. In the suprarenal aneurysm group, the 30-day mortality rate was 2.9% (1/34). Preoperative renal insufficiency was present in 16 patients, respectively in 7 patients with juxtarenal aneurysms and in 9 patients with suprarenal ones. In 22 patients, we registered a transient increase in creatinine levels with return to baseline levels by discharge. Four patients required long-term dialysis. In three patients, a short period of dialysis was required. Clamping time longer than 30 min was associated with a higher risk of transient postoperative deterioration of renal function (p = 0.0073). Preoperative renal insufficiency was associated with a higher risk of persistent postoperative deterioration of renal function (p < 0.0001). Morbidity and mortality of elective surgery for pararenal aneurysms is acceptable. One of the main risks of this surgery is renal morbidity. Preoperative renal insufficiency and long periods of renal ischemia are associated with a higher risk of postoperative deterioration of renal function that is often, but not always, reversible. Nowadays, pararenal aneurysm repair is a safe procedure, especially if performed electively.     

Critical Analysis of Outcome Determinants Affecting Repair of Intact Aneurysms Involving the Visceral Aorta

Visceral (mesenteric and/or renal) ischemia/reperfusion phenomena likely contribute to the greater operative risk associated with pararenal and lower thoracoabdominal aortic aneurysm (TAA) repair. To differentiate the relative adverse effects of aortic clamp level, visceral ischemic duration, and various pre- and perioperative factors shared with infrarenal aneurysm patients, a comparative analysis of early and late outcomes after open repair of intact infrarenal and visceral aortic aneurysms was undertaken. A retrospective review of our university experience from 1993-1999/2002 revealed 549 patients (mean age 70 ± 8 years, 11% female) undergoing open repair of intact, degenerative aneurysms of the infrarenal (n = 391, 71%), juxtarenal (n = 78, 14%), suprarenal (n = 35, 7%), and type IV (n = 40, 7%) and type III (n = 5, 1%) TAA segments. All pararenal aneurysms required suprarenal (SR) or supravisceral (SV, above celiac or superior mesenteric artery) clamp placement. Concomitant renal reconstruction was done in 30% of visceral aortic and 3% of open infrarenal aneurysm repairs. Thirty-day adverse outcomes [death, renal failure (creatinine 2 × baseline or new dialysis), visceral (bowel, hepatic, renal, spinal cord, multiple organ dysfunction), and nonvisceral (cardiac, pulmonary, procedural) complications] were analyzed relative to patient and operative factors using univariate comparisons and multivariate stepwise logistic regression. Perioperative mortality rates varied significantly between aneurysm locations (infrarenal 2.1%, juxtarenal 2.6%, suprarenal 11.4%, TAA 13.3%; p < 0.01) and for clamp locations (infrarenal 2.1%, SR 3.0%, SV 10.8 %; p < 0.01) but were not different between juxtarenal (1.8% vs. 4.4 %) and SR (9.1% vs. 12.5%) aneurysms requiring SR or SV clamping, respectively. Visceral ischemic time (VIT) during SR or SV clamping, and not clamp location, was the only independent predictor of operative mortality [odds ratio (OR) = 10.8, 95% confidence interval (CI) 4-29]. Sensitivity analyses revealed VIT > 32 min to be the strongest predictor of early death. Visceral complication or renal failure affected 34% and 23% of visceral aortic (5% dialysis) and 7% and 5% (1% dialysis) of infrarenal repairs, respectively. VIT > 32 min, SV clamp placement, diabetes, and inflammatory aneurysm repair were each predictive of visceral complications and/or renal failure. Five-year survival rate was similar after visceral aortic (70%) and infrarenal (75%) repairs but negatively impacted only in patients with prior infrarenal abdominal aortic aneurysm repair and recurrent aneurysms (OR = 2.8, 95% CI 1.2-6.9). The high incidence of early adverse outcomes following repair of pararenal and lower thoracoabdominal aneurysms is primarily associated with excessive periods of renal and/or gut ischemia during visceral aortic clamp placement. However, nearly equivalent early and late survival was seen for visceral aortic and infrarenal repairs when VIT < 32 min was achieved.Presented at the Twenty-eighth Annual Meeting of the Southern Association for Vascular Surgery, Rio Grande, Puerto Rico, January 14-17, 2004.     

Totally laparoscopic juxtarenal aortic anastomosis: an experimental study

The surgical management of juxtarenal aneurysms necessitates suprarenal aortic clamping and control of the renal arteries. We attempted to reproduce this procedure laparoscopically. Five female piglets were submitted to a totally laparoscopic approach of the aortoiliac segment. After laparoscopic control of the renal arteries and suprarenal clamping, a 6-mm Dacron tube graft was anastomosed to the juxtarenal aorta. After the procedure, a midline laparotomy allowed verification of the patency of the renal arteries and the quality of the anastomosis. Mean operative time was 198 minutes (range, 170-240 minutes). The dissection took an average of 92 minutes (range, 75-110 minutes). The mean suprarenal aortic cross-clamp time was 46.3 minutes (range, 29.1-81.5 minutes), and the mean anastomotic time was 28.9 minutes (range, 16.5-68.1 minutes). This study demonstrates in this animal model the feasibility of juxtarenal aortic anastomosis using a laparoscopic technique. Newly designed instruments should allow a shorter clamping time in the future.     

Suprarenal aortic cross-clamping in elective abdominal aortic aneurysm surgery.

INTRODUCTION: this retrospective study was undertaken to evaluate whether suprarenal aortic cross-clamping increased the perioperative mortality and morbidity as compared to infrarenal clamping, in order to create the rationale for a more extensive application of this apparently more traumatic manoeuvre. MATERIALS AND METHODS: in a series of 734 elective aortic substitutions for abdominal aneurysm (AA), performed consecutively from January 1992 to June 1999, aortic cross-clamping was performed at a suprarenal level in 56 juxtarenal aneurysms, i.e. aneurysms extending to the lower edge of the renal arteries (8%, Group 1), and at an infrarenal level in 634 subrenal aneurysms (92%, Group 2). When analysing preoperative data, the diameter of aneurysms was larger in Group 1 than in Group 2 (p<0. 005). No significant differences were found between the two groups as regards age, sex, postinfarction cardiomyopathy, chronic obstructive pulmonary disease, chronic renal insufficiency and ASA classification of operative risks. RESULTS: the average time of renal exclusion in the juxtarenal aneurysms was 20 min (range 12-35 min). There is no difference between the two groups as regards the time of aortic clamping (mean 50 vs. 60 min) or the need for homologous blood transfusion (7% vs. 11% of patients). Perioperative (30 days) mortality did not differ: 3.6% vs. 1.9% (n.s.); nor did the incidence of acute myocardial infarction (3.6% vs. 2.3%). Renal function deteriorated in 8 (14%) vs. 0 (0%) (p<0.001) and 1 patient (2%) required permanent dialysis, as compared to 0% in Group 2. The incidence of ischaemic colitis was also significantly higher in Group 1 (7%) than in Group 2 (2%, p<0.01). CONCLUSION: this data shows that suprarenal clamping, which is necessary for the radical treatment of juxtarenal aortic aneurysms, can be performed with a low risk.     

Open repair of pararenal aortic aneurysms

Surgical treatment of pararenal aortic aneurysms, if compared to open repair of infrarenal aneurysms, is characterized by more technical difficulties and haemodynamic problems. Since endovascular repair has become feasible in most cases of infrarenal aneurysms, surgical treatment of pararenal aneurysms is a matter of great interest for vascular surgery. Detection of pararenal aneurysms needs a careful preoperative diagnosis, assessment of cardiac, renal and pulmonary status of the patient and planning of the surgical intervention. The surgeon needs to face an extended proximal aorta exposure, to manage the left renal vein and to choose an appropriate clamping site. Then a skilled and quick reconstruction of the visceral arteries is fundamental to minimize organ disfunction. Coupled intraoperative selective perfusion of visceral arteries and systemic administration of nephroprotective drugs optimizes organ protection during ischemia. To better define challenges, risks and results, we reviewed our experience with the treatment of pararenal aortic aneurysms. In the period between January 1993 and May 2003, 98 consecutive patients underwent surgery for pararenal aneurysms at our Institution. We treated 98 pararenal aneurysms, divided in 68 juxtarenal and 30 pararenal ones. In the juxtarenal aneurysms group, the 30 days mortality rate was 5.8% (4/68); 3 of these patients underwent urgent operation for ruptured aneurysm. In the suprarenal aneurysms group, the 30 days mortality rate was 3.3% (1/30). In conclusion pararenal aneurysm repair is a safe procedure, especially if performed electively, and represents an interesting field of research to improve surgical and anesthesiologic techniques.     

Open repair for pararenal abdominal aortic aneurysm: the strategy and pitfalls for safe surgery

Pararenal abdominal aortic aneurysm (PRAAA) includes two types of AAA : juxtarenal (JRAAA) and suprarenal (SRAAA). JRAAA is defined as aneurysms that extend up to but do not involve the renal arteries, necessitating suprarenal aortic clamping for repair. SRAAA is defined as aneurysms that extend up to the superior mesenteric artery, involving one or both renal arteries to be repaired. The surgical repair of PRAAAs requires more extensive aortic exposure and may result in ischemic injury to kidneys and visceral organs with higher morbidity and mortality compared with infrarenal AAAs. The four approaches to PRAAA repair are: 1) midline abdominal incision, transperitoneal, left renal vein divided or mobilized; 2) midline abdominal incision, transperitoneal, left medial visceral rotation technique 3) left flank incision, retroperitoneal; and 4) thoracoabdominal incision, thoracoretroperitoneal approach. The four positions of proximal clamping are: 1) suprarenal; 2) interrenal; 3) supramesenteric; and 4) supraceliac aorta. The surgical strategy should be determined based on computed tomography and magnetic resonance angiography imaging, and severe atherosclerotic or calcified aorta should never be clamped to prevent lethal embolic complications. Although developing fenestrated endovascular technology can be used in some cases of PRAAA repair, open surgery with thorough preoperative assessment and careful utilization of techniques to prevent visceral and renal ischemic injury is safe, effective, and durable and remains the gold standard for repair.     

Contemporary results of juxtarenal aneurysm repair

OBJECTIVE: The increasing use of aortic endografts predictably will add to the complexity of open abdominal aortic aneurysm (AAA) repair and, therefore, the proportion of surgically treated infrarenal AAAs that are juxtarenal in location (JRA) will grow. This study reviews a single-center experience with JRAs. METHODS: Between June 1994 and December 2000, 138 patients underwent elective repair of a JRA, comprising 16.1% of 859 consecutive asymptomatic and intact symptomatic nonruptured infrarenal AAAs repaired over the same period. All patients with JRA needed proximal suprarenal clamping (SRC) or supravisceral (SVC) clamping. Patient demographics, selected risk factors, and operative details were recorded. Univariate analyses of selected risk factors for an adverse perioperative event were assessed, and multivariate analyses were performed with linear and logistic regression with backwards selection. RESULTS: SRC was used in 95 patients (69%), and 43 patients (31%) underwent SVC. The mortality rate was 5.1% (7/138) for JRA repair, and 2.8% (20/720) for infrarenal AAA repair (P =.03). The mortality rate was significantly greater for those patients who received SVC compared with SRC (11.6% versus 2.1%; P =.02). Multivariate analysis identified SVC position as the only independent predictor of mortality (odds ratio [OR], 6.1; 95% CI, 1.1 to 32.9; P =.035). Transient renal insufficiency occurred in 39 patients (28.3%), but only eight patients (5.8%) needed dialysis. Patients who had SVC had a significantly greater rate of renal insufficiency than those who received SRC (41.9% versus 22.1%; P =.02). Multivariate analysis showed SVC position (OR, 3.3; 95% CI, 1.4 to 7.8; P =.008), diabetes (OR, 3.7; 95% CI, 1.1 to 12.9; P =.04), and preoperative renal insufficiency (OR, 5.8; 95% CI, 2.2 to 15.4; P <.001) were independent predictors of postoperative renal insufficiency. Renal ischemia during proximal clamping cannot alone explain renal complications because clamp time was shorter in patients with SVC (24.9 +/- 2.4 minutes versus 32.2 +/- 1.5 minutes; P =.009). CONCLUSION: JRA repair can be accomplished with a low mortality rate, but a more proximal clamp position may adversely affect outcome in these patients. Postoperative renal insufficiency is related to diabetes, preoperative renal insufficiency, and SVC position. These results suggest SRC is safer than SVC for proximal aortic clamp control of JRAs. Although clamp level must be tailored to patient anatomy, outcome may be improved if the clamp level can be kept distal to the superior mesenteric artery origin.     

Effect of suprarenal versus infrarenal aortic endograft fixation on renal function and renal artery patency: a comparative study with intermediate follow-up

PURPOSE: Suprarenal fixation of aortic endografts appears to be a safe option in patients with a short or conical proximal aortic neck. However, concern persists regarding the long-term effect on renal function when renal artery ostia are crossed by the uncovered stent. We investigated the effect of suprarenal versus infrarenal endograft fixation on renal function and renal artery patency after endovascular aortic aneurysm repair. METHODS: Records of 91 patients who underwent endovascular aortic aneurysm repair with a modular bifurcated stent graft between November 1999 and January 2002 were reviewed retrospectively. Two patients receiving dialysis because of chronic renal failure were excluded. Infrarenal fixation was used in 57 patients (group 1), and suprarenal fixation was used in 32 patients (group 2). In two patients in group 1 a Gianturco Z stent was inserted transrenally because of intraoperative proximal type I endoleak, and data for these patients were excluded from analysis. Follow-up evaluation was performed at 1, 6, and 12 months, and yearly thereafter, and included clinical assessment, measurement of serum creatinine concentration (SCr), and computed tomography angiography, per standard protocol. Median follow-up was 12 months (range, 1-36 months). RESULTS: There was no statistically significant difference in patient demographic data, aneurysm size, or preoperative risk factors. Median SCr was significantly higher in group 2 (suprarenal fixation) than in group 1 (infrarenal fixation) preoperatively (1.2 mg/dL [range, 0.6-2.3 mg/dL] vs 0.9 mg/dL [range, 0.6-1.9 mg/dL], P =.008) and at 1 month postoperatively (1.1 mg/dL [range, 0.8-5.6 mg/dL] vs 1.0 mg/dL [range, 0.6-2.1 mg/dL], P =.045). There was a significant increase in median SCr in both groups at 1 month postoperatively (group 1, 1.0 mg/dL [range, 0.6-2.1 mg/dL], P =.05; group 2, 1.1 mg/dL [range, 0.8-5.6 mg/dL] [mean SCr, 1.35 mg/dL vs 1.15 mg/dL, respectively], P <.05). In group 1 SCr was increased significantly at 6 and 12 months (P <.001), whereas in group 2 SCr also increased at 6 and 12 months, but not significantly. The change in SCr over time was not significantly different between the two groups. In two of 32 patients in group 2, renal artery occlusion developed, associated with perfusion defects in renal parenchyma and persistently elevated SCr. Analysis of renal artery patency did not demonstrate any association between patency and treatment. No patient developed hypertension during follow-up. CONCLUSIONS: Suprarenal endograft fixation does not lead to significant renal dysfunction, and renal artery occlusion is uncommon within 12 months. A larger study with longer follow-up is essential to determine overall effects on renal function and renal artery patency.     

Open repair of juxtarenal aortic aneurysms (JAA) remains a safe option in the era of fenestrated endografts

OBJECTIVES: Widespread application of infrarenal endovascular aneurysm repair (EVAR) has resulted in a proportionate increase in open juxtarenal aortic aneurysm (JAA) repairs. Fenestrated endograft technology for JAA is developing rapidly, but only limited outcomes are known. The aim of this study was to review our open JAA experience in an era of fenestrated endograft technology, identify factors associated with increased surgical risk, determine early and midterm outcome, and provide a basis for comparison for future endovascular procedures. METHODS: Data from 126 consecutive patients who underwent elective JAA repair requiring suprarenal aortic clamping from 2001 to 2006 were analyzed retrospectively. Electronic medical chart reviews were used to record 30-day complication rates. Multivariate analyses were performed to identify risk factors associated with surgical morbidity. Mail-out questionnaires and telephone surveys were conducted to determine long-term follow-up. RESULTS: Ninety-eight males and 28 females (median age 74 years; range 55 to 93) were included in the study. Preoperative risk factors included: coronary artery disease (CAD) 58%, pulmonary disease 41%, renal insufficiency (serum creatinine [Cr] > 1.5mg/dL) 17%, and diabetes 9%. Fifteen patients underwent concomitant renal artery revascularization. Mean operative time was 319 minutes (range 91 to 648). Thirty-day mortality was 1/126 (0.8%). Median hospital length of stay was 7 days (range 3 to 85); median intensive care unit length of stay was 2 days (1 to 64). Complications included renal insufficiency (Cr increase > 0.5 mg/dL) in 22 (18%), cardiac in 17 (13%), and pulmonary in 14 (11%). Five patients required temporary hemodialysis; only one after hospital dismissal. Mean follow-up was 48 months (range 9-80). On multivariate analysis, age > or = 78 years (P = .001), male gender (P = .04), hypertension (P =.01), previous myocardial infarction (P = .047), and diabetes (P =.009) were predictive of cardiac complications. Renal artery revascularization (P = .01) and prior MI (P = .04) were multivariate predictors of pulmonary complications. Both prolonged operative (> or =351 minutes, P = .02) and renal ischemia (> or =23 minutes, P =.004) times predicted postoperative renal insufficiency. One, 3, and 5-year cumulative survival rates were 93.9%, 78.3%, and 63.8%, respectively and were not significantly different than an age- and gender-matched sample of the US population (P = .16). Mortality was not predicted by any specific risk factors. CONCLUSIONS: Open surgical repair of JAA is associated with low mortality and remains the gold standard. Although 18% had renal complications, only one patient had permanent renal failure. Patients with a combination of physiologic and anatomic risk factors identified on multivariate analysis may benefit from fenestrated endograft repair.     

Hypothermic renal protection using cold histidine-tryptophan-ketoglutarate solution perfusion in suprarenal aortic surgery

We examined data of 21 patients who were treated with selective perfusion of both renal arteries with 500 mL of 8 degrees C histidine-tryptophan-ketoglutarate (HTK) solution each for renal protection during aortic surgery. Only the data from aortic surgeries with unavoidable suprarenal aortic cross-clamping for juxtarenal or suprarenal abdominal aortic aneurysms (AAAs) or high Leriche syndrome accompanied with stenosis of renal arteries are presented. Five patients underwent immediate surgery because of perforation of an AAA; the other 16 patients went through elective surgeries. In three cases (14%) stenosis of the renal arteries was diagnosed; nevertheless, implantation of an aortorenal bypass was necessary in seven patients. In total, 14 aortorenal bypasses were implanted (five venous grafts and nine prosthesis grafts). Four (19%) patients needed catecholaminergic support to establish stable circulatory conditions; in two (9%) of these cases additional ischemia of the colon was observed and sigmoidectomy was performed. All of these four patients underwent immediate surgery, and one died after surgery because of severe sepsis. In four cases postsurgical renal insufficiency was observed. Three of these patients were admitted for emergency surgery because of their hemodynamic situation due to perforation of the AAA. None of the patients needed chronic dialysis after surgery. Whereas in all patients who underwent elective surgery the renal function remained stable as judged by postoperative serum creatinine values, in five out of seven patients with aortorenal bypass surgery the renal function improved. Perfusion with cold HTK solution offers an additional procedure to protect renal function in patients undergoing elective surgery with suprarenal cross-clamping of the aorta.     

The impact of ischemia time during open nephron sparing surgery on solitary kidneys: a multi-institutional study

PURPOSE: The safe duration of ischemia during nephron sparing surgery remains controversial. We performed a multi-institutional study to evaluate the renal effects of vascular clamping in patients with solitary kidneys. MATERIALS AND METHODS: Using the Cleveland Clinic and Mayo Clinic databases, we identified 537 patients with solitary kidneys who underwent open nephron sparing surgery. Renal complications were compared among patients who did not require vascular clamping (85), and those who had warm ischemia (174) and cold ischemia (278). RESULTS: Median patient age (63, 65, 64 years) and preoperative creatinine (1.4, 1.3, 1.4 mg/dl) were similar among patients with no ischemia, warm ischemia and cold ischemia, respectively. Median tumor size was smaller in patients with no ischemia (2.5 cm), compared to patients with warm (3.5 cm) and cold (4.0 cm) ischemia (p <0.001). Warm and cold ischemia was associated with a significantly increased risk of urine leak (p = 0.006), acute (p <0.001) and chronic (p = 0.027) renal failure, and temporary dialysis (p = 0.028) compared to patients with no ischemia. Warm ischemia longer than 20 minutes and cold ischemia longer than 35 minutes were associated with a higher incidence of acute renal failure (p = 0.002 and p = 0.003, respectively). Additionally, warm ischemia more than 20 minutes was associated with an increased risk of chronic renal insufficiency (41% vs 19%, p = 0.008), increase in creatinine greater than 0.5 (42% vs 15%, p <0.001) and permanent dialysis (10% vs 4%, p = 0.145). CONCLUSIONS: Vascular clamping during open nephron sparing surgery is associated with a higher incidence of renal complications. Attempts to limit warm ischemia to 20 minutes and cold ischemia to 35 minutes should be used when vascular clamping is necessary.     

Renal dysfunction and prolonged visceral ischaemia increase mortality rate after suprarenal aneurysm repair

BACKGROUND: Elective juxtarenal abdominal aneurysm repair has a significantly lower mortality rate than suprarenal repair. Identification of factors affecting outcome may lead to a reduction in mortality rate for suprarenal repair. METHODS: Data were collected prospectively between 1993 and 2000 for 130 patients who underwent type IV thoracoabdominal aneurysm (TAA) repair and 44 patients who had juxtarenal aneurysm (JRA) repair. Preoperative risk factors and operative details were compared between groups and related to outcome after TAA repair (there were only two deaths in the JRA group). RESULTS: The in-hospital mortality rate was significantly higher following TAA repair (20.0 per cent; 26 of 130 patients) than JRA repair (4.5 per cent; two of 44). Raised serum creatinine concentration was the only preoperative factor (P = 0.013) and visceral ischaemia the only significant operative factor (P = 0.001) that affected mortality after TAA repair. CONCLUSION: JRA repair was performed with similar risks to those of infrarenal aneurysm repair. Impaired preoperative renal function was related to death following TAA repair and conservative treatment should be considered for patients with a serum creatinine level above 180 micromol/l. Reducing the duration of visceral ischaemia might improve outcome.     

Should initial clamping for abdominal aortic aneurysm repair be proximal or distal to minimise embolisation?

OBJECTIVES: to determine whether clamping proximally or distally on the infrarenal aorta during abdominal aortic aneurysm (AAA) repair increases the overall embolic potential. MATERIALS AND METHODS: a sheath was placed in the mid-infrarenal aorta of 16 dogs. In eight animals a cross-clamp was placed at the aortic trifurcation, and in another eight animals it was placed in the immediate subrenal position. Under fluoroscopy blood flow within the infrarenal aorta was evaluated by contrast and particle injections. Grey-scale analysis was used to calculate contrast density. Particle distribution was followed fluoroscopically and confirmed pathologically. RESULTS: fifty-seven+/-24% of injected contrast remained within the aorta with distal clamping while 97+/-7% did so with proximal clamping (p<0.01). With distal aortic clamping 6.2+/-1. 3 out of 10 injected particles remained within the aorta after 15 seconds and only 0.8+/-0.8 remained after 5 min. With proximal aortic clamping, all 10 of the particles remained within the aortic lumen for the full 5 minutes (p<0.001). CONCLUSIONS: initial distal clamping minimises distal embolisation, but may result in renal and/or visceral embolisation. Initial proximal clamping prevents proximal embolisation and does not promote distal embolisation. We recommend initial proximal clamping in aortic aneurysm surgery to minimise the overall risk of embolisation.     

Pararenal aortic aneurysms: the future of open aortic aneurysm repair

PURPOSE: As endovascular stent graft repair of infrarenal abdominal aortic aneurysms (AAAs) becomes more common, an increasing proportion of patients who undergo open operation will have juxtarenal aneurysms (JR-AAAs), which necessitate suprarenal crossclamping, suprarenal aneurysms (SR-AAAs), which necessitate renal artery reconstruction, or aneurysms with associated renal artery occlusive disease (RAOD), which necessitate repair. To determine the current results of the standard operative treatment of these patterns of pararenal aortic aneurysms, we reviewed the outcome of 257 consecutive patients who underwent operation for JR-AAAs (n = 122), SR-AAAs (n = 58), or RAOD (n = 77). METHODS: The patients with SR-AAAs and RAOD were younger (67.5 +/- 8.8 years) than were the patients with JR-AAAs (70.5 +/- 8.3 years), and more patients with RAOD were women (43% vs 21% for JR-AAAs and SR-AAAs). The patient groups were similar in the frequency of coronary artery and pulmonary disease and in most risk factors for atherosclerosis, except hypertension, which was more common in the RAOD group. Significantly more patients with RAOD had reduced renal function before surgery (51% vs 23%). Supravisceral aortic crossclamping (above the superior mesenteric artery or the celiac artery) was needed more often in patients with SR-AAAs (52% vs 39% for RAOD and 17% for JR-AAAs). Seventeen patients (7%) had undergone a prior aortic reconstruction. The most common renal reconstruction for SR-AAA was reimplantation (n = 37; 64%) or bypass grafting (n = 12; 21%) and for RAOD was transaortic renal endarterectomy (n = 71; 92%). Mean AAA diameter was 6.7 +/- 2.1 cm and was larger in the JR-AAA (7.1 +/- 2.1 cm) and SR-AAA (6.9 +/- 2.1 cm) groups as compared with the RAOD group (5.9 +/- 1.7 cm). RESULTS: The overall mortality rate was 5.8% (n = 15) and was the same for all the groups. The mortality rate correlated (P <.05) with hematologic complications (bleeding) and postoperative visceral ischemia or infarction but not with aneurysm group or cardiac, pulmonary, or renal complications. Renal ischemia duration averaged 31.6 +/- 21.6 minutes and was longer in the SR-AAA group (43.6 +/- 38.9 minutes). Some postoperative renal function loss occurred in 104 patients (40.5%), of whom 18 (7.0%) required dialysis. At discharge or death, 24 patients (9.3%) still had no improvement in renal function and 11 of those patients (4.3%) remained on dialysis. Postoperative loss of renal function correlated (P <.05) with preoperative abnormal renal function and duration of renal ischemia but not with aneurysm type, crossclamp level, or type of renal reconstruction. CONCLUSION: These results showed that pararenal AAA repair can be performed safely and effectively. The outcomes for all three aneurysm types were similar, but there was an increased risk of loss of renal function when preoperative renal function was abnormal. These data provide a benchmark for expected treatment outcomes in patients with these patterns of pararenal aortic aneurysmal disease that currently can only be managed with open repair.