Surgical results of abdominal aortic aneurysm repair in patients with chronic renal dysfunction

Postoperative renal dysfunction independently predicts late mortality in patients undergoing aortic reconstruction

OBJECTIVE

Preoperative chronic kidney disease (CKD) has been shown to predict postoperative renal complications and mortality after open aortic surgery; the impact of postoperative renal complications less severe than permanent dialysis are unknown. We evaluated the impact of postoperative renal dysfunction severity on survival using a regional quality improvement registry.

METHODS

Patients undergoing intact open aortic reconstruction in the Vascular Study Group of New England registry (2003-2012) were stratified by severity of postoperative renal complications; none, creatinine increase of greater than 0.5 mg/dL (incCr), or any hemodialysis (HD). Predictors of renal dysfunction and impact of renal complications on survival were analyzed using multivariable methods.

RESULTS

We included 2695 patients, of which 65% (n = 1733) underwent open abdominal aortic aneurysm repair, and 35% (n = 962) open aortoiliac reconstruction. At baseline, 15% of patients had preoperative moderate CKD and 1.2% had severe CKD. Postoperative renal complications of incCr occurred in 8.5% of patients, and 1.5% required HD. Multivariable cumlogit regression identified severe baseline CKD (odds ratio [OR], 15; 95% confidence interval [CI], 6.4-34; P < .001, moderate CKD (OR, 2.8; 95% CI, 1.9-3.3; P < .001), suprarenal clamp use (OR, 2.2; 95% CI, 1.6-2.9; P < .001), perioperative vasopressor requirements (OR, 2.2; 95% CI, 1.6-2.9; P < .001), operating time (OR, 1.004 per minute; 95% CI, 1.003-1.006; P < .001), and chronic obstructive pulmonary disease (OR, 1.5; 95% CI, 1.2-1.8; P < .001) as independent predictors of worsening strata of postoperative renal dysfunction. Multivariable logistic regression analysis showed that patient age (OR, 1.06 per year; 95% CI, 1.01-1.1; P = .01), baseline chronic obstructive pulmonary disease (OR, 1.6; 95% CI, 1.2-2.2; P < .01), incCr (OR, 3.7; 95% CI, 1.8-7.4; P = .009), and HD (OR, 4.8; 95% CI, 1.8-12.7); P = .009) independently increased 30-day mortality. Risk-adjusted multivariable Cox regression showed that incCr (hazard ratio, 1.8; 95% CI, 1.3-2.6; P < .001) and HD (hazard ratio, 4.4; 95% CI, 2.8-6.9; P < .001) increased risk of late death independent of a variety of other clinical variables, including baseline CKD. The 5-year survival was lower (log-rank P < .001) in patients with incCr (66% ± 4%), and HD (38% ± 10%) compared with those with no renal complications (77% ± 1%).

CONCLUSIONS

Increasing severity of postoperative renal dysfunction independently predicts increased risk of late mortality after open aortic surgery. Perioperative measures to decrease renal complications may potentially prolong the survival of patients after open aortic surgery.

Transperitoneal repair of a juxtarenal abdominal aortic aneurysm and co-existent horseshoe kidney with division of the renal isthmus

The co-existence of abdominal aortic aneurysm (AAA) and horseshoe kidney (HSK) is rare. We report a 67-year-old man with an expanding juxtarenal AAA associated with a HSK. The aneurysm had a severely angulated neck and contained a significant amount of mural thrombus. The isthmus of HSK closely lied over the aneurysm, making its exposure extremely difficult. The aneurysm was successfully repaired using transperitoneal approach with division of the renal isthmus and without any need for the renal artery reconstruction. Despite the potential complications, particularly renal insufficiency, associated with division of the renal isthmus and suprarenal cross-clamping of the abdominal aorta, in our case, post-operative period was uneventful and the patient's recovery was satisfactory.

Impact of chronic kidney disease on outcomes after abdominal aortic aneurysm repair

OBJECTIVE

Chronic kidney disease (CKD) is associated with increased morbidity and death after open abdominal aortic aneurysm (AAA) repair (OAR). This study highlights the effect of CKD on outcomes after endovascular AAA (EVAR) and OAR in contemporary practice.

METHODS

The National Surgical Quality Improvement Program (NSQIP) Participant Use File (2005-2008) was queried by Current Procedural Terminology (American Medical Association, Chicago, Ill) code to identify EVAR or OAR patients, who were grouped by CKD class as having mild (CKD class 1 or 2), moderate (CKD class 3), or severe (CKD class 4 or 5) renal disease. Propensity score analysis was performed to match OAR and EVAR patients with mild CKD with those with moderate or severe CKD. Comparative analysis of mortality and clinical outcomes was performed based on CKD strata.

RESULTS

We identified 8701 patients who were treated with EVAR (n = 5811) or OAR (n = 2890) of intact AAAs. Mild, moderate, and severe CKD was present in 63%, 30%, and 7%, respectively. CKD increased (P < .01) overall mortality, with rates of 1.7% (mild), 5.3% (moderate), and 7.7% (severe) in unmatched patients undergoing EVAR or OAR. Operative mortality rates in patients with severe CKD were as high as 6.2% for EVAR and 10.3% for OAR. Severity of CKD was associated with increasing frequency of risk factors; therefore, propensity matching to control for comorbidities was performed, resulting in similar baseline clinical and demographic features of patients with mild compared with those with moderate or severe disease. In propensity-matched cohorts, moderate CKD increased the risk of 30-day mortality for EVAR (1.9% mild vs 3.2% moderate; P = .013) and OAR (3.1% mild vs 8.4% moderate; P < .0001). Moderate CKD was also associated with increased morbidity in patients treated with EVAR (8.3% mild vs 12.8% moderate; P < .0001) or OAR (25.2% mild vs 32.4% moderate; P = .001). Similarly, severe CKD increased the risk of 30-day mortality for EVAR (2.6% mild vs 5.7% severe; P = .0081) and OAR (4.1% mild vs 9.9% severe; P = .0057). Severe CKD was also associated with increased morbidity in patients treated with EVAR (10.6% mild vs 19.2% severe; P < .0001) or OAR (31.1% mild vs 39.6% severe; P = .04).

CONCLUSIONS

The presence of moderate or severe CKD in patients considered for AAA repair is associated with significantly increased mortality and therefore should figure prominently in clinical decision making. The high mortality of AAA repair in patients with severe CKD is such that elective repair in such patients is not advised, except in extenuating clinical circumstances.

Why routine intensive care unit admission after elective open infrarenal Abdominal Aortic Aneurysm repair is no longer an evidence based practice

BACKGROUND

Elective open infrarenal Abdominal Aortic Aneurysm (AAA) repair is major surgery performed on high-risk patients. Routine ICU admission postoperatively is the current accepted standard of care. Few of these patients actually require a level of care that cannot be provided just as effectively in a surgical high dependency unit (HDU). Our aim was to determine, 'can high risk patients that will require ICU admission postoperatively be reliably identified preoperatively?'.

METHODS

A retrospective analysis of all elective open infrarenal AAA repairs in our institution over a 3-year period was performed. The Estimation of Physiological Ability and Surgical Stress (E-PASS) model was used as our risk stratification tool for predicting post-operative morbidity. Renal function was also considered as a predictor of outcome, independent of the E-PASS.

RESULTS

80% (n = 16) were admitted to ICU. Only 30% (n = 6) of the total study population necessitated intensive care. There were 9 complications in 7 patients in our study. The E-PASS comprehensive risk score (CRS)/Surgical stress score (SSS) were found to be significantly associated with the presence of a complication (p = 0.009)/(p = 0.032) respectively. Serum creatinine (p = 0.013) was similarly significantly associated with the presence of a complication.

CONCLUSIONS

The E-PASS model possessing increasing external validity is an effective risk stratification tool in safely deciding the appropriate level of post-operative care for elective infrarenal AAA repairs.

Predictors of morbidity and mortality with endovascular and open thoracic aneurysm repair

BACKGROUND

Open and endovascular thoracic aneurysm repairs are associated with significant complications including paraplegia, stroke, vascular insufficiency, and death. Predictors of adverse outcomes are not well-defined in this patient population.

METHODS

The database of the GORE TAG (W.L. Gore, Flagstaff, Ariz) Pivotal Trial comparing the TAG endograft to open repair was interrogated. Univariate (UVA) and multivariate analyses (MVA) of demographic, clinical, anatomic, and procedural variables were conducted to discover possible predictors of serious adverse events for the whole group and for the TAG and open cohort groups separately. Early adverse outcomes occurred within 30 days or the initial hospitalization. P value of < or = .05 was significant.

RESULTS

A total of 140 TAG and 94 open descending thoracic aneurysm (DTA) patients were analyzed, consisting of 128 men and 106 women. Perioperative deaths were 9/94 for open surgery and 3/140 for TAG patients, with 10/12 (7 open, 3 TAG) deaths occurring in men. Two female deaths were both after open surgery. Multivariate analysis showed predictors of death for all patients were symptomatic aneurysms and male gender. Analysis of a combined morbidity/mortality endpoint (stroke/paralysis/MI/death) showed elevated creatinine predicted these events for the whole group. Open surgery (P < .001) and increasing aneurysm diameter (P < .001) predicted an increased likelihood of any major adverse event. Open surgery was significantly associated with an increased risk of paraplegia (P = .002). Vascular complications were more frequent in the TAG (19%) than in open DTA patients (9%) (P = .038). Female gender (P = .01) predicted vascular complications within the endovascular group. For all analyses, long procedure times were correlated with adverse events. Women were noted to have longer procedure times for both TAG and open repairs.

CONCLUSION

Elevated creatinine levels and symptomatic aneurysms predict morbidity and mortality, respectively, regardless of repair type. Male gender predicted death after open surgery, and since most deaths (9 of 12) were in this group, male gender predicted death overall, despite women's more difficult endovascular TAA repairs as evidenced by longer procedure times and higher vascular complication rates. All major adverse events and paraplegia were more common for open surgery patients.

Abdominal Aortic Aneurysm with Coexistent Horseshoe Kidney

Surgical repair of an abdominal aortic aneurysm (AAA) concomitant with a horseshoe kidney (HSK) may be technically demanding because of the complex anomalies of the kidney and of its collecting system and arteries, the greater risk of HSK-related complications, and the often unexpected intraoperative finding of HSK itself. We reviewed a database of more than 500 patients with AAA observed in our surgical department from 1994 to the time of writing. Five patients had AAA concomitant with HSK. Two of these patients did not undergo surgery because of the small dimension of the aneurysm or because of their poor health. The other three underwent successful repair of AAA with different techniques; namely, an aortobifemoral bypass via a thoracoabdominal retroperitoneal incision in one, a straight graft via an emergency median laparotomy in one, and an endovascular repair followed by open surgery 4 years later for endotension in one. Abnormal minor renal arteries were deliberately occluded and only one of these caused a minor renal infarct, but without functional impairment. These data and a review of the literature indicate that HSK should not preclude repair of coexistent AAA, as imaging procedures provide the information necessary to plan the best approach for each patient. Up-to-date surgical procedures, a posteriori retroperitoneal approach or endovascular repair, and deliberate occlusion of the minor renal arteries appear feasible and safe as they avoid most of the anatomical problems and provide results equivalent to those of uncomplicated aortic surgery.

Carbon dioxide digital subtraction angiography-assisted endovascular aortic aneurysm repair in the azotemic patient

OBJECTIVE

This report analyzes the safety and efficacy of carbon dioxide digital subtraction angiography (CO(2)-DSA) for EVAR in a group of patients with renal insufficiency compared with a concurrent group of patients with normal renal function undergoing EVAR with iodinated contrast angiography (ICA).

METHODS

Between 2003 and 2005, 100 consecutive patients who underwent EVAR using ICA, CO(2)-DSA, or both were retrospectively reviewed, and preoperative, intraoperative, postoperative, and follow-up variables were collected. Patients were divided into two groups depending on renal function and contrast used. Group I comprised patients with normal renal function in whom ICA was used exclusively, and group II patients had a serum creatinine >or=1.5 mg/dL, and CO(2)-DSA was used preferentially and supplemented with ICA, when necessary. The two groups were compared for the outcomes of successful graft placement, renal function, endoleak type, and frequency, and the need for graft revision. Comparisons were made using chi(2) analysis, Student t test, and the Fisher exact test.

RESULTS

A total of 84 EVARs were performed in group I and 16 in group II. Patient demographics and risk factors were similar between groups with the exception of serum creatinine, which was significantly increased in group II (1.8 mg/dL vs 1.0 mg/dL P < .0005). All 100 endografts were successfully implanted. Patients in group II had longer fluoroscopy times, longer operative times, and increased radiation exposure, and 13 of 16 patients required supplemental ICA. Mean iodinated contrast use was 27 mL for group II vs 148 mL in group I (P < .0005). Mean postoperative serum creatinine was unchanged from baseline, and 30-day morbidity was similar for both groups. No patient required dialysis. No patients died. Perioperatively, and at 1 and 6 months, the endoleak type and incidence and need for endograft revision was no different between groups.

CONCLUSIONS

CO(2)-DSA is safe, can be used to guide EVAR, and provides outcomes similar to ICA-guided EVAR. CO2-DSA protects renal function in the azotemic patient by lessening the need for iodinated contrast and associated nephrotoxicity, but with the tradeoff of longer fluoroscopy and operating room times and increased radiation exposure.

The Management of Abdominal Aortic Aneurysms in Patients with Concurrent Renal Impairment

INTRODUCTION

Patients with concurrent renal impairment and abdominal aortic aneurysms present a significant challenge in terms of pre-operative, intra-operative and post-operative management. This aim of this review was to determine the risks of surgery in this patient group and determine whether any clear management strategies exist to enhance their clinical management.

METHODS

Systematic review of published literature giving details of the outcome of open or endovascular abdominal aortic aneurysm repair in patients with pre-operative renal impairment. Papers concerning the management of post-operative acute renal failure in patients with normal pre-operative renal function has not been included.

RESULTS

There is little data regarding patients with end-stage renal failure and AAA although these patients appear to have a high peri-operative mortality rate. In contrast, those with renal impairment do not have a significantly higher mortality rate than those with normal renal function, rather they have a higher risk of complications associated with surgery and may require more intensive post-operative organ system support than normal patients. Many have a transient deterioration in renal function in the immediate peri-operative period that will resolve. In the case of patients with ruptured AAA, it is not clear whether pre-operative renal impairment affects mortality.

Abdominal Aortic Aneurysm Repair in Patients with Chronic Renal Disease

OBJECTIVES

To assess the outcome of AAA repair in patients with established renal failure (RF), including patients on dialysis.

DESIGN

Retrospective case-control study in a teaching hospital. Methods. All patients with established RF undergoing AAA repair were identified during the last eight years. Data was collected from patient notes on operative difficulty, hospital mortality, survival time and future dialysis requirements. For comparison, 28 consecutive patients undergoing AAA repair without RF were studied prospectively.

RESULTS

Thirteen RF patients were identified. Three were receiving Continuous Ambulatory Peritoneal Dialysis (CAPD), three were receiving Haemodialysis (HD) and seven had established RF, but were not receiving dialysis. Compared with the control patients, RF patients had a longer total hospital stay (p=0.03, 95% CI for median stay -24.3 to -4.0 days), more postoperative complications (p<0.01, 95% CI 26.4-73.7%) and had an increased in-hospital mortality (p=0.02, 95% CI 4.6-54.3%). Four of the six survivors who were non-dialysis-dependent required long-term dialysis postoperatively.

CONCLUSIONS

AAA repair in RF patients is associated with increased postoperative morbidity and mortality. Previously non-dialysis-dependent patients have a high risk of subsequent long-term dialysis.

Factors affecting late survival after elective abdominal aortic aneurysm repair

BACKGROUND

The late prognosis after repair of an abdominal aortic aneurysm (AAA) may be affected by atherosclerosis, which involves various organs including the aorta.

METHODS

The influence of organ dysfunction and atherosclerosis on the long-term survival of 338 consecutive patients undergoing successful elective AAA repair between 1980 and 1997 was analysed using Cox hazards model. Survival rate was compared with that of 349 patients undergoing successful revascularization for aortoiliac occlusive disease (AIOD) during the same interval.

RESULTS

Renal dysfunction and a previous history of cerebrovascular events were important variables predicting late death (risk ratio 1.980 and 1.903 respectively), while a history of cardiac disease predicted only cardiac-related death. The survival rate in patients with normal renal function was significantly better than that in those with renal dysfunction (P = 0.0371). Similarly, the survival rate was significantly better in patients without a history of previous cerebrovascular events (P = 0.0414). The survival rate after AAA repair was nearly identical to that of age- and sex-matched patients with grade II or III symptoms who had surgery for AIOD.

CONCLUSION

Advanced atherosclerosis with underlying organ dysfunction is a true determinant of long-term survival following elective repair of AAA.

Acute renal impairment due to a primary aortocaval fistula is normalised after a successful operation

OBJECTIVES

To study renal function in patients with aortocaval fistula, before and after surgery.

DESIGN

Retrospective study.

MATERIAL AND METHODS

During the last 22 years nine male patients (median age 67, age range 50-72) with spontaneous aortocaval fistula in combination with AAA were operated upon. This constitutes 4% of the patients with ruptured AAA and 1.5% of all patients with AAA.

RESULTS

A preoperative diagnosis of aortocaval fistula was established in three of the nine cases. The medium duration of symptoms prior to surgery was 5 days (range 4 h-14 days). The fistula was combined with an extravasating ruptured AAA in only three patients. Seven of the patients had acute renal insufficiency, with creatinine levels of in median 292 mumol (IQR 218-342). Creatinine declined to 172 mumol/l (IQR 170-313) on the fifth postoperative day in uncomplicated cases and to 86 mumol at discharge. One patient died due to multi-organ failure, whereas the other left hospital well and alive with normal renal function.

CONCLUSION

Acute preoperative renal insufficiency due to an aortocaval fistula in patients with AAA is often due to venous congestion, and is normalised after successful surgery.