Effects of Abdominal Aortic Aneurysm Size on Mid- and Long-term Mortality After Endovascular Aneurysm Repair.

PURPOSE: To investigate the effect of abdominal aortic aneurysm (AAA) size on mid- and long-term survival after endovascular aneurysm repair (EVAR). MATERIALS AND METHODS: Retrospective data were collected from 325 consecutive patients (mean age 69.7 ± 8.5 years; 323 men) who underwent EVAR for intact AAA at a single institution between January 2003 and December 2013. The primary endpoint was death at 3, 5, and 10 years after EVAR. Optimal cutoff points for AAA size and age were determined using receiver operating characteristics (ROC) curves. Time to event analyses (Kaplan-Meier curves and Cox proportional hazard models) were employed to determine any differences in all-cause mortality outcomes between AAA size groups. Cox models were adjusted for age and other comorbidities (hypertension, hyperlipidemia, coronary artery disease, smoking status, symptomatic status, and creatinine); the outcomes are reported as the hazard ratio (HR) with 95% confidence interval (CI). RESULTS: The cohort was dichotomized according to the ROC analysis, which defined an optimal cutoff point of 5.6 cm for AAA size and >70 years for age. The mean follow-up period post EVAR was 45.5±29.2 months. In total, 134 (41.2%) patients died during the 10-year follow-up. Thirty-day mortality was 1.1% (2/184) in the patients with AAA <5.6 cm and 2.1% (3/141) in patients with AAA ≥5.6 cm (p=0.45). All-cause mortality was not significantly affected by comorbidities. However, AAA size ≥5.6 cm was associated with increased 3-year mortality risk (HR 1.59, 95% CI 1.001 to 2.52, p<0.049) but not 5-year (HR 1.44, 95% CI 0.98 to 2.10, p=0.062) or 10-year mortality (HR 1.28, 95% CI 0.91 to 1.80, p=0.149). After adjusting for comorbidities, AAA size ≥5.6 cm was no longer significantly associated with morality at any time point. Using a larger size cutoff (AAA size ≥6.0 cm) resulted in improved statistical significance in the unadjusted model. In the adjusted Cox model, AAA size ≥6.0 cm was significantly associated with increased risk of mortality at 3 years (HR 1.67, 95% CI 1.01 to 2.77, p<0.047), but not at longer time points. CONCLUSION: Our study demonstrates that midterm survival after EVAR is significantly and independently associated with AAA size even after correcting for comorbidities. However, in the long term, preoperative AAA size is not an independent predictor of mortality.

Rate of Secondary Intervention After Open Versus Endovascular Abdominal Aortic Aneurysm Repair.

BACKGROUND: Although long-term durability and improved perioperative outcome of endovascular abdominal aortic aneurysm (AAA) repair has been demonstrated, some studies have suggested an increased rate of secondary interventions compared with open AAA repair. More recent data suggest that rates between the two modalities may be similar. We investigated the rate of secondary intervention in patients undergoing endovascular aortic aneurysm repair (EVAR) or open AAA repair for intact AAA and the effect of secondary intervention on long-term mortality in these two groups of patients. METHODS: A retrospective, single-institution review was conducted between January 2003 and December 2012. Secondary intervention was defined as any intervention within 30 d of the procedure or an AAA repair-related procedure after 30 d, which included repair of endoleaks and incisional hernia repair. Group differences in demographic and baseline characteristics were examined using Cochran-Mantel-Haenszel and Wilcoxon rank sum tests for categorical and continuous variables, respectively. RESULTS: A total of 342 patients underwent operative repair of intact AAA. Two hundred seventy four patients underwent EVAR and 68 patients underwent open AAA repair. The mean age overall was 68.6 y and was not significantly different between the two repair groups. The overall rate of secondary intervention was significantly lower in the EVAR group compared with the open AAA repair group (11% versus 27%, P = 0.001). In the EVAR group, 30 patients underwent 37 secondary interventions. In the open repair group, 18 patients underwent 20 reinterventions. The most common secondary intervention was repair of type 2 endoleak (n = 13, 4.7% of patients) after EVAR and incisional hernia repair (n = 4, 5.9% of patients) after open AAA repair. Most secondary interventions (15/20) after open AAA repair occurred within 30 d, whereas most secondary intervention (33/37) after EVAR occurred after 30 d. Comparison of late (>30 d) reintervention between the two groups revealed a significantly lower rate of secondary intervention after open AAA repair (27.8% of all reinterventions after open versus 86.7% of all reinterventions after EVAR, P < 0.001). The overall 10-y mortality rate was 39.1%, and not statistically different between the two repair groups. Estimated survival analysis demonstrated no significant effect of secondary intervention on mortality after EVAR (logrank P = 0.45). Secondary intervention after open repair did not significantly affect long-term survival (logrank P = 0.05). CONCLUSIONS: This study highlights the dramatic change in practice pattern in AAA repair over time. In this study, patients treated with EVAR had a significantly lower overall rate of secondary intervention compared with patients treated with open AAA repair. This was likely secondary to increased perioperative morbidity and mortality and a bias toward more complex patients in the open repair group. In the long term, however, there were significantly fewer reinterventions after open AAA repair. Secondary interventions did not affect long-term survival after EVAR.

Electrophysiologic deterioration in surgery for thoracic disc herniation: impact of mean arterial pressures on surgical outcome.

OBJECTIVE: Severe thoracic disc herniation leads to increased pressure in adjacent neural structures, which in turn can require an increase in mean arterial pressure (MAP) to maintain adequate spinal cord perfusion. We report a case series of three patients with severe thoracic disc herniation that experienced deteriorations in motor-evoked potentials (MEPs) and somatosensory evoked potentials (SSEPs) following induction of general anesthesia, but prior to decompression of the neural elements. METHODS: In-depth chart reviews were completed for each patient from their initial presentation to long-term post-operative course. Careful attention was taken with regards to MAP at induction of each operative case. RESULTS: The origin of the decreased signals in all patients was thought to relate to inadequate cord perfusion pressures. Two of the patients recovered pre-operative neurologic function while the third was left with mild post-operative paraparesis. Mean arterial pressures at time of deterioration were noted to be 58, 80, and 60 mmHg. These measurements represented MAPs approximately 65, 92, and 60 % those of baseline values, respectively. CONCLUSION: Based on these experiences, the authors' institution has adopted new guidelines in the setting of thoracic disc herniations that includes pre-operative optimization of volume status, placement of an awake arterial line prior to induction of anesthesia, use of MEP and SSEP electrophysiologic monitoring, careful selection of anesthetic, and aggressive maintenance of MAPs >110 % of preoperative values at all times prior to decompression of the spinal cord.

Neonatal carotid repair at ECMO decannulation: patency rates and early neurologic outcomes.

PURPOSE: Neonates placed on veno-arterial extracorporeal membrane oxygenation (VA-ECMO) undergo either carotid repair or ligation at decannulation. Study aims were to evaluate carotid patency rates after repair and to compare early neurologic outcomes between repaired and ligated patients. METHODS: A retrospective study of all neonates without congenital heart disease (CHD) who had VA-ECMO between 1989 and 2012 was completed using our institutional ECMO Registry. Carotid patency after repair, neuroimaging studies, and auditory brainstem response (ABR) testing at time of discharge were examined. RESULTS: 140 neonates were placed on VA-ECMO during the study period. Among survivors, 84% of carotids repaired and imaged remained patent at last study. No significant differences were observed between infants in the repaired and ligated groups regarding diagnosis, ECMO duration, or length of stay. A large proportion (43%) developed a severe brain lesion after VA-ECMO, but few failed their ABR testing. Differences in early neurologic outcomes between the two groups of survivors were not significant. CONCLUSIONS: At this single institution, carotid patency is excellent following repair at ECMO decannulation. No increased incidence of severe brain lesions or greater neurosensory impairment in the repair group was observed. Further studies are needed to investigate the effects of ligation on longer-term neurocognitive outcomes.