Cold visceral perfusion improves early survival in patients with acute renal failure after thoracoabdominal aortic aneurysm repair

INTRODUCTION: Despite advances in organ protection during thoracoabdominal aortic aneurysm (TAAA) repair, acute renal failure (ARF) remains a significant clinical problem, associated with increased morbidity and mortality. We studied outcome of ARF after TAAA repair in patients who underwent either warm or cold visceral perfusion. METHOD: Between 1991 and 2001 657 TAAA repairs were performed, of which 359 (55%) had either warm or cold visceral perfusion. Twelve patients with renal failure who had undergone preoperative dialysis were excluded from the study. Of the remaining 347 patients, ARF developed in 81 (23%) after TAAA repair. Forty-four (54%) of the 81 patients with ARF received cold visceral perfusion, and 37 (46%) patients received warm visceral perfusion. ARF was defined as either an increase of 1 mg/dL in serum creatinine (SCr) concentration per day for 2 consecutive days or dialysis requirement. Patient records were reviewed through hospital discharge. RESULTS: Twenty six (32%) of the 81 patients in whom ARF developed died, 17 of 37 (46%) patients in the warm perfusion group versus 9 of 44 (21%) patients in the cold perfusion group (P <.02). Median onset of ARF was on postoperative day 1 in both groups. Twenty-six of 81 (32%) patients recovered renal function, 10 of 37 (27%) patients in the warm perfusion group versus 16 of 44 (36%) patients in the cold perfusion group. Preoperative SCr concentration was predictive of recovery of renal function (odds ratio, 4.5 per mg/dL increase; P <.03) in patients who received either warm or cold visceral perfusion. CONCLUSIONS: ARF after TAAA repair remains a significant clinical problem. Recovery of renal function occurred in approximately one third of patients. Preoperative SCr concentration was the only significant determinant of recovered renal function. While cold visceral perfusion did not alter renal recovery, it significantly reduced hospital mortality.     

Abdominal aortic aneurysm repair in patients with preoperative renal failure

The purpose of this study was to determine the effect of preoperative renal failure on the outcome of patients undergoing infrarenal abdominal aortic aneurysm (AAA) repair. Of 251 patients undergoing AAA repair from 1977 to 1984, 10% had evidence of preoperative chronic renal failure. These patients were classified according to their preoperative serum creatinine values; group I had preoperative creatinine levels of 2 to 4 mg/dl, group II had creatinine levels greater than 4 mg/dl but no history of hemodialysis, and group III consisted of patients on chronic hemodialysis before operation. One of 16 patients in group I developed transient high-output renal failure postoperatively. Four of the six patients in group II (67%) developed significant postoperative deterioration of renal function and required acute hemodialysis. Of the four patients in group III maintained on chronic hemodialysis preoperatively, one died of sepsis from an ischemic colon. This experience suggests that patients with mild renal dysfunction (serum creatine value less than 4 mg/dl) can undergo elective AAA repair without additional morbidity. Patients on hemodialysis before operation can also safely undergo surgical repair of their AAAs electively if dialyzed the day before operation. Patients with severe renal dysfunction (serum creatinine greater than 4 mg/dl) who are not on hemodialysis should be considered for dialysis preoperatively in an attempt to reduce the high incidence of serious postoperative renal functional deterioration and subsequent morbidity.     

Preoperative selective intercostal angiography in patients undergoing thoracoabdominal aneurysm repair

OBJECTIVE: This study was designed to test the hypothesis that detection of the location of the major artery supplying the spinal cord, that is, the artery of Adamkiewicz or the great radicular artery (GRA), with angiography would help prevent paraplegia. Knowing which intercostal artery provides this important branch would enable prompt, focused revascularization. METHOD: The surgical outcome in 131 patients with Crawford extent 1 and 2 degenerative aneurysms and 69 patients with descending thoracic aortic dissection was correlated with findings on selective intercostal arteriograms. Angiographic maneuvers were done with care, and the procedures were aborted if there was loose or "shaggy" mural thrombus, significant tortuosity, or difficulty entering each dissection channel. No attempts were made to find major contributions proximal to T6. Subarachnoid drains were placed in all patients, and all but five patients underwent distal aortic perfusion with controlled cooling to 32 degrees F. Five patients underwent cold circulatory arrest, enabling replacement of the distal aortic arch. We defined paraplegia simply as the inability to walk at hospital discharge, paraparesis as impaired ambulation, and both as having spinal cord dysfunction (SCD). RESULTS: A GRA was found in 65 (43%)of the 151 patients studied. Of the 65 patients with the GRA identified, SCD developed in 3 (4.6%) patients. Thirteen of 135 (9.6%) patients in whom the GRA was not identified, either because they were not studied or were studied and the GRA was not found, developed SCD (P =.35) However, when the GRA was identified, SCD occurred only in the group with aortic dissection. None of the 45 patients with degenerative aneurysms with the GRA identified had SCD, compared with 9 of 55 (16%) patients studied but without a GRA found (P =.01). CONCLUSION: The approach with selective intercostal angiography did not improve overall results. One third of our patients were not studied, and they fared as well as patients who were studied and the GRA was localized (not studied, 4 of 49, 8% with SCD; GRA localized, 3 of 65, 5% with SCD; P =.8). However, when the GRA was found, SCD occurred only in patients with aortic dissection. The studies confirmed the concept that the existence of mural thrombus in degenerative aneurysms results in the occlusion of many intercostal arteries, leaving those remaining patent to supply rich vascular watersheds through acquired collateral channels. As a result, in the group of patients with degenerative aneurysms, the identification of the critical intercostal artery allows focused reimplantation with uniform success. This is not the case in patients with aortic dissection. In those patients, most intercostal vessels remain patent, such that the insertion of one pair is insufficient to supply the paravertebral plexus and the spinal cord. Finally, failure to identify the GRA angiographically with our methods does not provide assurance that the GRA does not exist. Therefore negative findings did not provide license to ligate all intercostal arteries.     

Midterm outcome of renal function after branched thoracoabdominal aortic aneurysm repair

ObjectiveThe aim of this study was to investigate the incidence and impact of acute and chronic kidney dysfunction after branched endovascular aortic aneurysm repair (BEVAR) perioperatively and during follow-up.MethodsPatients with a thoracoabdominal aortic aneurysm were treated with BEVAR. Serum creatinine; estimated glomerular filtration rate at baseline, after 48 hours, at discharge, and after 1 and two years; perioperative results; and outcome during follow-up were evaluated.ResultsTreatment of thoracoabdominal aortic aneurysm using BEVAR was performed in 113 patients (mean age, 71 years; 79 male) with 434 side branches and two additional fenestrations (0.46%) for renovisceral perfusion. Sixty patients (53%) underwent staged procedures with temporary aneurysm sac perfusion and secondary side branch completion. Perioperative mortality was 9 of 113 (8%). Postoperative acute kidney injury (AKI) was observed in 41 of 113 patients (36%) with recovery of renal function after 2 years in most patients. However, chronic kidney disease (CKD) stage progression after 1 and 2 years was observed in 25 of 104 patients (24%) and 17 of 52 patients (32.7%), respectively. Seven patients (6.7%) required permanent dialysis during 2 years of follow-up. Risk factors for AKI were nonstaged procedures (P = .02) and multiorgan failure (P = .01). CKD progression was related to renal branch reinterventions (P = .047), all branch reinterventions (P = .03), and postoperative AKI (P = .001). During follow-up, survival was decreased in patients with AKI, especially in those with nonmalignant diseases (P = .01).ConclusionsPostoperative AKI after BEVAR was observed in about one-third of patients associated with increased CKD stages after 2 years. Preoperative CKD was not a risk factor for postoperative AKI or perioperative outcome. The prevention of AKI by staged procedures, early interventions for renal side branch complications, and regular surveillance is recommended to improve outcomes.     

Functional outcome after thoracoabdominal aortic aneurysm repair

OBJECTIVE: Repair of thoracoabdominal aortic aneurysms (TAAAs) is performed for the improvement of long-term survival and the preservation of function. The determination of functional outcome and the identification of predictors of survival and functional recovery after TAAA repair are key to proper patient selection. METHODS: This retrospective review of clinical data was performed in an academic medical center. The demographics, Crawford aneurysm type (I-18, II-33, III-22, IV-28), preoperative risk factors, operative characteristics, and postoperative complications and outcomes were recorded from the medical records for 101 consecutive patients who underwent TAAA repair (58 elective and 43 urgent/emergent). Functional status and living situation at hospital discharge and 12 months after discharge were determined from follow-up examination records or telephone contact with surviving patients. The patients then were categorized into "good" (survival, home, discharge to rehabilitation center, ambulatory) or "bad" (death, discharge to or residence in a long-term care facility, non-ambulatory) outcomes. RESULTS: The postoperative mortality rate was 17.8% (10% in elective cases and 28% in urgent cases), and significant postoperative complications occurred in 77% of the cases (pulmonary complications in 41%, renal complications in 28%, and cord injury in 12%). The mean length of stay was 22.8 + 23.6 days, and at discharge, 80% of the patients were sent to home or rehabilitation and 20% were sent to long-term care facilities. At 1 year, 15 additional patients had died. All but two patients who had been initially discharged to rehabilitation had returned home, but only two patients who had been discharged to long-term care facilities had returned home and both were nonambulatory. Therefore, the survival rate at 1 year was 67%, and only 52.4% of the patients had a "good" outcome at 1 year (survival rate was 78% and rate of "good" outcome was 63% in patients who underwent elective TAAA repair). Independent predictors of postoperative death and "bad" outcome were age more than 75 years, preoperative heart disease, duration of visceral ischemia, use of left atrial femoral bypass graft, postoperative renal dysfunction, and number of organs failing after surgery. CONCLUSION: Survival and good functional outcome after TAAA repair is significantly less common than expected and is primarily predicted with intraoperative factors and postoperative complications. Improved operative techniques and limitation of visceral ischemia reperfusion injury may improve outcome after TAAA repair.     

Risk assessment of acute renal failure after thoracoabdominal aortic aneurysm surgery.

OBJECTIVE: The authors sought a statistical model that permits the calculation of the chance of postoperative dialysis in patients undergoing thoracoabdominal aortic aneurysm repair. The preoperative risk of each individual patient was assessed. SUMMARY BACKGROUND DATA: Acute renal failure requiring dialysis after thoracoabdominal aortic aneurysm surgery is a common complication. Despite modern intensive care facilities, it continues to be associated with high morbidity and mortality. METHODS: The authors studied the influence of preoperative and intraoperative variables thought to be important clinically in the development of serious acute renal failure in 88 consecutive patients. Simple cross-clamping was used with the Crawford's graft inclusion technique without shunts or heparin. Statistical methods used include univariate and multivariate analysis (stepwise logistic regression analysis and Cox proportional hazard model). RESULTS: The hospital mortality was 11.4% (n = 10). Long-term survival at 2 years was 78% (+/- 4.4), and at 5 years was 54% (+/- 5.3). A logistic regression model with only two explanatory variables to predict postoperative dialysis showed an almost perfect fit (chi 2 = 4.2, p = 0.84): the risk factors of postoperative dialysis were age (p = 0.003) and the preoperative serum creatinine level (p = 0.04). As determined by stepwise Cox regression analysis, postoperative dialysis also was a significant risk factor for late death (p = 0.002). CONCLUSIONS: Using this statistical model, the chances of postoperative dialysis can be estimated exactly before operation; age and preoperative serum creatinine level are the only variables predictive for postoperative dialysis.     

Durability of thoracoabdominal aortic aneurysm repair in patients with connective tissue disorders

OBJECTIVE: Thoracoabdominal aortic aneurysm (TAAA) repair is a durable procedure performed with reasonable perioperative mortality and morbidity in patients with atherosclerotic aortic disease. However, the long-term outcome and durability of TAAA repair performed in patients with a connective tissue disorder (CTD) is not well known. METHODS: The records of 257 patients who underwent TAAA repair at the Johns Hopkins Hospital between January 1992 and December 2001 were reviewed. Survival analysis was performed with Kaplan-Meier analysis, and subgroups were compared with the log-rank test. Multivariable analysis was performed with the Cox proportional hazards model and logistic regression. RESULTS: Patients with CTD (n = 31) were seen earlier (mean age, 48.6 +/- 2.9 years) than patients without CTD (mean age, 69.1 +/- 0.6 years; P <.0001, Mann-Whitney U test) and had a greater incidence rate of aortic dissection (52% versus 19%; P <.0001, chi(2) test) and extent I or II aneurysm (77% versus 64%; P =.04). The perioperative (30-day) mortality rate was 6.5% in patients with CTD, which was similar to the rest of the cohort (P =.39, Fisher exact test). The incidence rate of paraparesis/paraplegia was 12.9%/6.5% in patients with CTD, and CTD was the only factor predictive of paraparesis (P =.03; odds ratio, 9.3; logistic regression). The cumulative survival rate among the entire cohort was 53.4% +/- 4.4% at 5 years (Kaplan-Meier), and no difference was seen among patients with or without CTD (P =.16, log-rank test) or among different Crawford extents (P =.29). Of the two late (>6 months) deaths in patients with CTD, none were from aortic rupture or dissection, compared with two of 31 late deaths in patients without CTD. Multivariable analysis confirmed that postoperative renal failure (P =.03) predicted mortality but neither CTD (P =.93), nor Crawford extent (P =.21, Cox regression) predicted mortality. Among survivors, no mean difference was found in largest aortic diameter on follow-up imaging in patients with or without CTD (4.7 +/- 0.3 cm versus 4.4 +/- 0.3 cm; P =.47, Mann-Whitney U test). The cumulative graft patency rate, representing long-term graft stability and with death, rupture, dissection, or recurrent aneurysm as endpoints, was 47.5% +/- 4.6% at 5 years (Kaplan-Meier) and was similar in patients with or without CTD (P =.10, log-rank test). CONCLUSION: TAAA repair appears to be a durable operation, with a reasonable 5-year patient survival rate and a low risk of postoperative paraplegia or additional aortic events. Patients with CTD can expect their outcome, including long-term survival and aortic stability, to be similar to patients without CTD.     

Bacterial translocation in patients undergoing abdominal aortic aneurysm repair

BACKGROUND: Bacterial translocation occurs in humans and is associated with an increased incidence of septic morbidity. The aims of this study were to determine the prevalence of bacterial translocation in patients undergoing open abdominal aortic aneurysm (AAA) repair and to identify any association with postoperative septic complications. METHODS: This was a prospective observational study in which patients undergoing aneurysm repair were assessed for evidence of bacterial translocation by culture of a mesenteric lymph node (MLN), small bowel serosal exudate and thrombus within the aneurysm. All postoperative septic complications were recorded. RESULTS: A total of 51 patients was studied (40 men, 11 women; median age 72 years). Enteric bacteria were isolated from the MLNs of five patients (prevalence of bacterial translocation 10 per cent), one of whom also yielded growth from the serosal exudate. Septic morbidity occurred in four of five patients in whom bacterial translocation was identified, compared with nine of 46 in those without translocation (P = 0.013, Fisher's exact test, mid P). One patient in whom Escherichia coli was grown from the MLN developed an aortoenteric fistula, with a coliform species isolated from the graft. CONCLUSION: This study suggests that bacterial translocation occurs in patients undergoing AAA repair. It is associated with an increased incidence of postoperative septic morbidity and provides a possible mechanism for infection of prosthetic aortic grafts.     

Mid-term results of patients undergoing endovascular aortic aneurysm repair

BACKGROUND: The utilization of endovascular aneurysm repair (EAR) is increasing significantly; however, few papers have outlined mid-term outcomes. METHODS: Patients undergoing EAR with an AneuRx endograft between September 1997 and May 2001 were evaluated. Mean follow-up was 20.7 +/- 11.9 (SD) months. RESULTS: In all, 101 EAR devices were successfully deployed in 105 attempts. Four open conversions (2 acute, 2 delayed) were performed for complications of EAR. Technical, clinical, and 1 to 3 year continuing success rates were 75%, 73%, and 78% to 83%. When divided by the median date, significantly fewer patients in the later group required secondary procedures compared with the early group. Vascular insufficiency occurred in 12 patients; 11 were treated with a secondary procedure. For 9 type I and 9 type II persistent endoleaks, secondary procedures were attempted and successful in 10 patients. Of successful EAR deployments, including secondary interventions, 85% demonstrated no persistent leak, rupture, increase in aneurysm size, or migration at most recent follow-up. CONCLUSIONS: EAR is successful in selected individuals; however, continuing follow-up is of paramount importance.     

Hybrid repair of thoracoabdominal aortic aneurysm in high-risk patients using a quadrifurcated graft

Surgical treatment for thoracoabdominal aortic aneurysm is still challenging and is associated with a high risk of paraplegia. Hybrid repair with stent graft insertion for the thoracoabdominal aorta excluding the branches of the lumbar and visceral arteries and bypass grafting to the visceral branches has been introduced as a less invasive treatment that reduces the risk of paraplegia. For hybrid repair, it is important to have appropriate management of the revascularized grafts to the 4 visceral arteries with sufficient inflow. We have recently adopted a knitted quadrifurcated graft applied inversely from the abdominal aorta or the iliac artery to the 4 visceral arteries; the celiac, superior mesenteric, and bilateral renal arteries. To date, we have used the graft in hybrid repair of thoracoabdominal aortic aneurysm in 2 high-risk elder patients who had disseminated intravascular coagulopathy and severe renal failure, respectively. We found that a knitted quadrifurcated graft was easy to handle and useful for reducing the number of anastomoses, which were expected to shorten the operation time. Postoperative courses were uneventful without paraplegia in either patient. Postoperative computed tomography showed excellent patency of the inversely applied quadrifurcated graft without any endoleak or migration in the thoracoabdominal stent. In conclusion, revascularization of 4 visceral arteries using a quadrifurcated graft should be considered a preferable option in hybrid treatment for thoracoabdominal aortic aneurysm.