Outcomes after abdominal aortic aneurysm repair: comparison of mortality defined by centralized VA Patient Treatment File data versus hospital-based chart review

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.

Association between Withholding Angiotensin Receptor Blockers in the Early Postoperative Period and 30-day Mortality

Background:

Despite widespread use, there is limited information to guide perioperative management of angiotensin receptor blockers (ARBs).

Methods:

In this retrospective cohort study, the authors evaluated the patterns of postoperative ARB use in veterans regularly prescribed ARBs admitted for noncardiac surgery at the Veterans Affairs Healthcare system between 1999 and 2011. Multivariable and propensity score–matched Cox proportional hazards models were used to determine the independent effect of failure to resume ARB by postoperative day 2 on the primary outcome of all-cause 30-day mortality.

Results:

Out of 1,167,482 surgical admissions, 30,173 inpatient surgical admissions met inclusion criteria. Approximately 10,205 patients (33.8%) in the cohort did not resume ARB by day 2. Those that resumed ARB had a 30-day mortality rate of 1.3% (260 of 19,968), whereas 3.2% (323 of 10,205) died in the group that withheld ARB. The unadjusted hazard ratio (HR) for 30-day mortality was 2.45 (95% CI, 2.08 to 2.89; P &lt; 0.001) for those that withheld ARB compared with those that resumed, whereas the multivariable adjusted HR was 1.74 (95% CI, 1.47 to 2.06; P &lt; 0.001). When restricted to a propensity score–matched subset of 19,490, the HR was similar (1.47; 95% CI, 1.22 to 1.78; P &lt; 0.001). Withholding ARB in younger patients increased mortality risk (HR = 2.52; 95% CI, 1.69 to 3.76; P &lt; 0.001 for age &lt;60 yr) compared with older patients (HR = 1.42; 95% CI, 1.09 to 1.85; P = 0.01 for age &gt;75 yr).

Conclusions:

Postoperative delay in resuming ARB is common, particularly in patients who are frail after surgery. Withholding ARB is strongly associated with increased 30-day mortality, especially in younger patients, although residual confounding may be present.

Perioperative use of beta-blockers remains low: Experience of a single Canadian tertiary institution

BACKGROUND

Perioperative beta-blockade appears to reduce morbidity and mortality in non-cardiac surgery, and is recommended by published guidelines. This study explores the frequency of perioperative beta-blockade and identifies factors limiting its use.

METHODS

We conducted a prospective analysis of consecutive patients seen by anesthesiologists before major non-cardiac surgery in a single month. Because not all patients undergoing major surgery were seen preoperatively by anesthesiologists, we also performed a retrospective analysis of patients who recently underwent such surgery. Data were collected on demographic information, cardiovascular risk factors, beta-blocker use, and perceived contraindications/barriers to beta-blocker use, using a validated instrument.

RESULTS

The prospective phase studied 222 patients preoperatively, of whom 96 were suitable candidates for perioperative beta-blockade by the American College of Physician guidelines. The retrospective phase studied 200 patients, of whom 63 were suitable candidates, and assessed pre- and postoperative use of beta-blockade. 40.6% and 38.1% of suitable patients received preoperative beta-blockade in the two phases, respectively. Findings were similar in those undergoing vascular surgery, suggesting that perception of perioperative risk did not influence the decision to use beta-blockade. Beta-blockers were not prescribed preoperatively because of lack of knowledge about contraindications to beta-blockade, and anesthesiologist reluctance to prescribe oral medication to outpatients.

DISCUSSION

Use of preoperative beta-blockade among suitable candidates appears to be approximately 40%. Anesthesiologists started preoperative beta-blockers infrequently even in patients without contraindications. These findings suggest that educating anesthesiologists about the perioperative use of beta-blockade may increase the use of this potentially beneficial strategy.

Hemipelvectomy for severe decubitus ulcers in patients with previous spinal cord injury

BACKGROUND

Patients with spinal cord injury (SCI) frequently have pressure ulcers. Surgery is sometimes needed to close them. In rare cases, hemipelvectomy is warranted for extremely severe complications.

METHODS

We conducted a retrospective study using national Department of Veterans Affairs (DVA) computer data sets to identify clinical features of SCI patients who underwent hemipelvectomy for life-threatening septic complications of decubitus ulcers.

RESULTS

Among the approximately 4 million patients receiving care in the DVA system, more than 40,000 patients were treated on an inpatient basis for SCI during the search period (fiscal years 1989 to 1998). They represent approximately 20% of the total national patient pool. There were 56 patients who supposedly had undergone hemipelvectomy. Chart review eliminated cases that did not meet our inclusion criteria, resulting in 8 evaluable cases. All had complete SCI due to trauma and later developed severe pressure sores with pelvic osteomyelitis or life-threatening soft tissue infection.

CONCLUSIONS

This series is the largest reported to date. The surgery involved significant blood loss (mean 2.6 L). Reoperations and complications were common. The mortality rate was 25%, but the survivors were all markedly improved by the surgery. Some of the complications appeared to be related more to the SCI than to the pelvic sepsis or surgery, suggesting that meticulous perioperative care may be valuable in reducing the complication rate in SCI patients undergoing this radical operation for very severe sequelae of pressure ulcers.

Cholecystectomy in patients with previous spinal cord injury

BACKGROUND

The number of people in the United States with spinal cord injury (SCI) is estimated at about 200,000. The prevalence of gallbladder disease in this population is about three times as high as in neurally intact people, but the results of surgical treatment have received little attention.

METHODS

A retrospective, population-based study of patients with SCI who later received cholecystectomy for benign gallbladder disease was performed. National computer data sets of all patients receiving medical care in all Department of Veterans Affairs (DVA) medical centers for fiscal years 1994 to 1998 were used. Computer-based data were augmented with chart-based resources.

RESULTS

During the period of interest, there were 21,849 patients with ICD-9-CM codes for SCI in the DVA computer system, among whom 367 had codes for cholecystectomy. After retrieval and review of data from individual charts, 118 were deemed evaluable. There were 68 who had successful laparoscopic cholecystectomy and 14 who required conversion to open cholecystectomy after laparoscopic efforts failed (conversion rate 14 of 82=17%). There were 36 who received planned open cholecystectomy. Patients under the age of 60 years were more likely to have a laparoscopic approach (P <0.05). Emergency cholecystectomies were more likely to be performed via the open route (P <0.01). The morbidity rate was 8 of 68 (12%) for successful laparoscopic cholecystectomy, 4 of 14 (29%) for failed laparoscopic surgery completed by conventional open technique, and 11 of 36 (31%) for planned open surgery. The mortality rate in the traditional surgery group was 1 of 36 (3%). There were no deaths in the other groups.

CONCLUSIONS

We believe this series is the largest so far reported. The mortality rate of cholecystectomy in SCI patients is comparable to that in neurally intact individuals, but the morbidity rate is high. Contractures, stomas, heterotopic ossification, and other sequelae of SCI do not generally cause technical difficulties with surgery. If complications of cholecystectomy are indeed SCI-related, attention to perioperative SCI care could improve outcomes of cholecystectomy. Future research should continue to explore this important research topic.

Risk stratification and outcomes of transluminal endografting for abdominal aortic aneurysm: 7-year experience and long-term follow-up

PURPOSE

To determine early and late outcomes of transluminal endografting (TE) in patients with abdominal aortic aneurysm (AAA), stratified by predicted risk of procedure-related mortality with conventional operation.

MATERIALS AND METHODS

A retrospective study was conducted in consecutive risk-stratified AAA patients undergoing TE at a not-for-profit cardiovascular referral center from March 1994 through November 2000 with follow-up through February 2001. With use of conventional risk strata (0 = low, 1 = minimal, 2 = moderate, and 3 = high), predicted procedure-related mortalities were 0%-1% in stratum 0 (n = 40), 1%-3% in stratum 1 (n = 118), 3%-8% in stratum 2 (n = 116), and 8%-30% in stratum 3 (n = 31). Main outcome measures were: (i) TE procedural success, (ii) procedure-related mortality, (iii) major nonfatal complications, (iv) composite adverse outcome (ii + iii), (v) length of stay (LOS), (vi) freedom from AAA rupture, (vii) late survival, (viii) late complications, and (ix) endoleaks and their classification and management.

RESULTS

Women were significantly less likely than men to qualify for and undergo endografting: 24 of 91 (26.4%) women underwent TE, compared to 281 of 684 (41.1%) men. Of 305 attempted TE procedures, 291 (95.4%) were successful, four (1.3%) were urgently converted to open repair, and 10 (3.3%) were aborted. Procedure-related mortalities occurred in eight cases (2.6%) overall and one of 40 (2.5%), one of 118 (0.8%), four of 116 (3.4%), and two of 31 (6.5%) cases for risk strata 0-3, respectively. Perioperative survivors were significantly younger than nonsurvivors (74.3 y +/- 9 vs 81.6 y +/- 5.1; P =.0087). Forty-six patients (15.1%) had major complications. Composite adverse outcome was worse for patients in stratum 3 than those in stratum 1 (P =.0296) and those in strata 0, 1, and 2 combined (P =.026). Procedure-related mortality declined with institutional experience, from 4% among the first 100 patients undergoing TE to 1% among the last 105. For strata 0-3, median LOS were 2, 3, 3, and 4 days, respectively. Seventy patients (22.9%) had 75 endoleaks, of which 30 necessitated additional procedures, 17 self-resolved, and 22 were untreated as of March 1, 2001. Five patients with endoleak died of unrelated causes. One late-onset type IA endoleak (26 mo) resulted in the only AAA rupture and death in the follow-up period among the 291 patients who underwent successful transluminal endograft implantation. Actuarial survival rates at 1 year after TE were 90.3% +/- 1.9% for the overall study group and 97.5% +/- 2.5%, 94% +/- 2.5%, 86.9% +/- 3.3%, and 81.3% +/- 7.7% for risk strata 0-3, respectively. At 5 years, overall actuarial survival was 69.6% +/- 6.1%. Thirty-eight late deaths were attributable to post-TE AAA rupture (n = 1), AAA rupture late after failed TE with no further treatment (n = 1), other cardiovascular disorders (n = 7), cancer (n = 15), other causes (n = 10), and unknown causes (n = 4). Late deaths occurred in risk strata 0-3 at the following rates: two of 40 (5%), 10 of 118 (8.5%), 16 of 116 (13.8%), and 10 of 31 (32.3%), respectively (stratum 0 vs stratum 3, P =.0017; stratum 1 vs stratum 3, P =.003).

CONCLUSIONS

TE is safe and confers durable protection against AAA rupture in treated populations. Still, protection is not absolute in patients with endoleaks, because late AAA enlargement and even rupture can occur. Given current knowledge, technology, and practice, careful patient selection and close surveillance of patients after implantation of transluminal endografts is essential.

Aneurysm rupture is independently associated with increased late mortality in those surviving abdominal aortic aneurysm repair

PURPOSE

The aim of this study was to define whether veterans who survived repair of ruptured abdominal aortic aneurysms (AAA) experienced late survival rates similar to those surviving repair of intact AAA.

METHODS

All veterans undergoing AAA repair in DRGs 110 and 111 during fiscal years 1991-1995 were identified using the Veterans Affairs (VA) Patient Treatment File (PTF). Late mortality was defined using VA administrative databases including the Beneficiary Identification and Record Locator System and PTF. Illness severity and patient complexity were defined using PTF discharge data that were further analyzed by Patient Management Category software. Veterans were followed up to 6 years after AAA repair.

RESULTS

During the study, 5833 veterans underwent repair of intact AAA while 427 had repair of ruptured AAA in all VA medical centers. Operative mortality was defined as that which occurred within 30 days of surgery or during the same hospitalization as aneurysm repair. For those undergoing repair of intact AAA, operative mortality thus defined was 4.5% (265/5833). Operative mortality was 46% (195/427) after repair of ruptured AAA. Overall mortality (including operative mortality) during 2.62+/-1.61 years follow-up was 22% (1282/5833) with intact AAA versus 61% (260/427) for those with ruptured AAA (P<0.001). Further analysis of survival outcomes was performed in patients who survived AAA repair (i.e., those who were discharged alive and lived 30 days or more after surgery). Of those who initially survived repair of ruptured AAA, 28% (65/232) died during follow-up versus 18% (1017/5568) who initially survived repair of intact AAA (odds ratio 1.74; 95% confidence limits 1.30-2.34; P<0.001). In those initially surviving AAA repair, stepwise logistic regression analysis revealed that increasing age, illness severity, patient complexity, as well as AAA rupture and aortic graft complications were increasingly and independently associated with late mortality. Mean survival time was 1681 days for those who survived >30 days and who were discharged alive after repair of ruptured AAA versus 1821 days for those who initially survived repair of intact AAA (P< 0.001).

CONCLUSIONS

In addition to higher postoperative mortality rates with ruptured AAA, mortality during follow-up for survivors of AAA repair was also greater for those who survived repair of ruptured AAA. The toll taken by ruptured abdominal aortic aneurysms did not end in the immediate postoperative period.