Spinal near-infrared spectroscopy measurements during and after thoracoabdominal aortic aneurysm repair: a pilot study.

BACKGROUND: Near-infrared spectroscopy (NIRS) is a noninvasive technique that allows continuous monitoring of regional hemoglobin oxygen saturation (rSo2). We evaluated its application to survey oxygenation of the spinal cord region during open thoracoabdominal aortic aneurysm (TAAA) repair and postoperatively in the intensive care unit (ICU). We also validated its association with motor-evoked potential (MEP) monitoring during the operation. METHODS: The rSo2 curves of 15 patients (8 men; mean age, 64.2 ± 7.7 years) were measured continuously with NIRS at spinal cord levels of the thoracic vertebrae T3 (optode 1, reference spot) and T12 (optode 2) during open TAAA repair. T12/T3 ratios were calculated. NIRS measurements were continued in the intensive care unit and stopped 24 hours after the operation. MEP monitoring was performed in all patients during the procedure. RESULTS: No clinical signs of spinal cord ischemia were documented in any of the patients. Continuous NIRS measurements were successfully performed in all patients during and after the operation. T12/T3 ratios were significantly lower in the MEP ratios that were less than 50% compared with the MEP ratios that were 50% or higher (p = 0.037). CONCLUSIONS: NIRS is an easily applicable noninvasive tool for continuous surveillance of oxygenation of the spinal cord region during TAAA repair and postoperatively in the intensive care unit. The rSo2 curves provide useful information concerning hemodynamic changes in oxygenation of the spinal cord region and might contribute to early detection of spinal cord ischemia. Further investigation is needed before broad clinical implementation.

Long-term results after 27 years of surgical treatment of acute type a aortic dissection.

BACKGROUND: This study investigates the determinants of long-term outcome and modalities of late death after surgical treatment of acute type A dissection. METHODS: Between 1974 and 2001, 315 consecutive patients were operated on for acute type A aortic dissection. Operative mortality was 22.9%. A series of 243 survivors of surgical treatment were followed up for as long as 27 years. Endpoints were death, cardiovascular reoperation, and neurologic events. Median follow-up was 4.5 years. Follow-up was 99.6% complete. RESULTS: Cumulative survival of discharged patients was 96.4% +/- 1.3%, 67.7% +/- 4.7%, and 39.4% +/- 12.0% at 1, 10, and 20 years, respectively. During follow-up, 47 patients died. Cause of death was cardiac failure in 7, hemorrhage due to rupture of the distal aorta in 7, stroke in 4, respiratory insufficiency in 4, sepsis in 3, malignancy in 2, and unknown in 20 patients. Multivariate analysis revealed advanced patient age and postoperative hemodialysis as perioperative indicators of late death (p < 0.05). Freedom from cardiovascular reoperation was 90.7% +/- 2.0% at 1 year, 60.9% +/- 5.1% at 10 years and 41.9% +/- 15.0% at 20 years. A total of 58 patients required 86 cardiovascular reoperations; aortic root or ascending aorta replacement was performed in 20, distal ascending aorta and arch replacement in 13, descending aorta replacement in 6, thoracoabdominal aorta replacement in 7, abdominal aorta replacement in 7, and miscellaneous reoperations in 6 patients. Multivariate analysis revealed male sex and left coronary artery dissection as significant determinants for late cardiovascular reintervention (p < 0.05). Cumulative incidence of stroke after 20 years was 3.8%. CONCLUSIONS: Acute type A dissection represents an emergency situation with acceptable long-term results for discharged survivors of surgical treatment.

Is extended arch replacement for acute type a aortic dissection an additional risk factor for mortality?

BACKGROUND: We report our experience with surgery for acute type A aortic dissection with involvement of the aortic arch. METHODS: From January 1986 to December 2001, 277 patients underwent surgery for acute type A aortic dissection. In 70 patients (25.3%), surgery was extended into the aortic arch: hemiarch and total arch replacement in 53 (75.7%) and 17 (24.3%) patients, respectively. Deep hypothermic circulatory arrest was used in 19 patients, antegrade selective cerebral perfusion in 38, and combined deep hypothermic circulatory arrest with antegrade selective cerebral perfusion in 13. RESULTS: Operative mortality was 18.6% (13/70) after extended replacement into the arch versus 21.7% (45/207) after surgery limited to the ascending aorta (p = 0.62). Multivariate analysis did not reveal significant risk factors for operative mortality. Postoperatively, 5 patients (8.1%) had a new postoperative cerebral vascular accident (CVA). Multivariate analysis showed an earlier date of operation as the only independent determinant for a new postoperative CVA (p = 0.0162, RR = 0.80/year, 95% CI = 0.67 to 0.96). None of the patients, operated on with antegrade selective cerebral perfusion, had a new cerebral deficit. Comparing the different methods of cerebral protection, multivariate risk analysis revealed antegrade selective cerebral perfusion as a significant protective factor against new postoperative CVA (p = 0.0110, OR = 0.12, 95% CI = 0.02 to 0.61). Survival at 5 and 10 years was 66.6.5% and 40.0%, respectively, after replacement of the aortic arch versus 68.7% and 57.7%, respectively, after replacement of the ascending aorta (p = 0.96). Freedom from aortic arch reoperation was 96.3% at 5 and 77.0% at 10 years versus 86.6% and 75.1% in both groups, respectively (p = 0.21). CONCLUSIONS: Extended replacement into the aortic arch during surgery for acute type A dissection does not influence early and late results. The best cerebral protection seems to be obtained with antegrade selective cerebral perfusion.

Operative risk factors of type A aortic dissection: analysis of 252 consecutive patients.

OBJECTIVE: We examined operative risk factors for postoperative death after surgery for acute type A aortic dissection. METHODS: Between 1974 and 1999, 252 patients, 163 men and 89 women (mean+/-SD age, 58+/-12 years) underwent surgery for acute type A aortic dissection. Fifty-eight (23.0%) were in cardiogenic shock at time of surgery. Most patients underwent ascending aorta replacement which was combined with aortic valve replacement by means of a composite graft in 30 (11.9%) patients and an isolated aortic valve replacement in 16 (6.3%) patients. RESULTS: The overall operative mortality rate was 25.0% (n=63); 27.0% for patients operated upon with aortic cross-clamping, 23.7% after deep hypotherm circulatory arrest and 23.3% after antegrade selective cerebral perfusion (ASCP) (p=0.73). Multivariate analysis revealed iatrogenic dissection (p=0.0096, odds ratio=5.7), preoperative cardiopulmonary resuscitation (p=0.0095, odds ratio=5.5) and every quarter of an hour longer extracorporeal circulation (p=0.049, odds ratio=1.1) as independent risk factors for operative mortality. Aortic valve replacement or Bentall procedure (p=0.0185, odds ratio=0.3) were protective factors. There were 44 new postoperative strokes: 4.7% in the group operated upon with and 20.1% in the group without ASCP (p=0.01). CONCLUSION: In order to avoid cardiogenic shock and preoperative cardiopulmonary resuscitation, patients with acute type A aortic dissection should be treated promptly. The choice to use an aortic valve prosthesis or Bentall procedure when applicable seems to benefit the postoperative early survival. The risk of new postoperative neurological events might be reduced by avoiding the appliance of an aortic cross-clamp and by using ASCP.