Is clamp and sew still viable for thoracic aortic resection?

OBJECTIVE: The authors reviewed the morbidity and mortality of surgical resection of the descending thoracic and thoracoabdominal aorta using the clamp-and-sew technique. BACKGROUND: Paraplegia remains a devastating complication after thoracoabdominal aortic resection, despite many strategies for spinal cord protection. Because of its simplicity, clamp and sew has been the preferred technique at the University of Virginia for the thoracoabdominal aortic resection when proximal control is possible. METHODS: Between 1987 and 1994, the authors reviewed 91 consecutive patients who underwent thoracic aortic resection using clamp-and-sew techniques without any additional adjuncts for spinal cord protection. RESULTS: The average age of patients was 60.8 years; 57.1% were male. No intraoperative deaths occurred. In-hospital mortality was 13% (12/91), with an overall incidence of postoperative spinal cord injury manifested as paraparesis or paraplegia of 9.9% (9/91). Eighty-nine percent (81/91) of all repairs were completed with aortic clamp times of 40 minutes or less, and nearly six out of ten were completed in 30 minutes or less (53/91). Cross-clamp times were not significantly different between those patients who sustained neurologic injury and those who had no deficits. CONCLUSIONS: The authors conclude that clamp and sew is still a viable technique for thoracoabdominal aortic resection. Nearly all resections can be completed within 40 minutes of aortic occlusion. However, the "safe" duration of thoracic aortic occlusion remains unknown, and spinal cord injury can occur even with short clamp times. Reproducible, safe, and technically simple means of spinal cord protection must be developed.

A simple technique for retrograde cerebral perfusion during circulatory arrest.

We describe a simple and safe technique for achieving retrograde cerebral perfusion via a small coronary sinus type catheter placed in the superior vena cava. This method is especially useful when the need for circulatory arrest is first recognized intraoperatively and a single two-stage venous cannula has already been placed for cardiopulmonary bypass. The advantages of this technique over other currently employed methods for retrograde cerebral perfusion are discussed.

Evolution of renal insufficiency in ischemic nephropathy.

This retrospective review of data collected during a recent 42-month period from 58 consecutive patients with ischemic nephropathy submitted to operative management in the authors' center was undertaken to report the rate of decline in their renal function during the period before intervention and to examine the impact of operation on their outcome. Based on serum creatinine values, immediate preoperative estimated glomerular filtration rates (EGFR) ranged from 0 to 46 mL/minute (mean, 23.85 +/- 9.76 mL/minute). Eight patients were dialysis dependent or anuric at the time of operation. Patients with at least three sequential measurements for calculations of EGFR changes during the 6 months before operation (n = 50) and the first 12 months after operation (n = 32) were used to describe the preoperative rate of decline in EGFR and the impact of operation on this decrease in the operative survivors. In addition comparative analyses of data from patients with unilateral versus bilateral lesions and patients classified as having improvement in EGFR versus no improvement after operation were performed. Comparison of the immediate preoperative EGFR with the immediate postoperative EGFR for the entire group showed significant improvement in response to operation. Likewise the rate of deterioration in EGFR for the total group was improved after operation. A similar improvement in the rate of deterioration in EGFR was seen in the subgroup of patients who received an immediate improvement in EGFR in response to operation. These data argue that ischemic nephropathy is a rapidly progressive form of renal insufficiency. Although individual responses to operation were heterogeneous, renal revascularization may provide both immediate improvement in renal function and an improvement in its rate of deterioration during follow-up in patients with ischemic nephropathy.

Renal duplex sonography: evaluation of clinical utility.

With the exception of conventional angiography, no previously proposed screening test has the necessary sensitivity/specificity to guide further evaluation for correctable renovascular disease. Recently, renal duplex sonography has been suggested as a useful substitute in such screening for renovascular disease. This report analyzes our data collected over the past 10 months in evaluation of renal duplex sonography to examine its diagnostic value. The study population for renal duplex sonography validity analysis consisted of 74 consecutive patients who had 77 comparative renal duplex sonography and standard angiographic studies of the arterial anatomy to 148 kidneys. Renal duplex sonography results from six kidneys (4%) were considered inadequate for interpretation. This study population contained 26 patients (35%) with severe renal insufficiency (mean 3.6 mg/dl) and 67 hypertension (91%). Fourteen patients (19%) had 20 kidneys with multiple renal arteries. Bilateral disease was present in 22 of the 44 patients with significant renovascular disease. Renal duplex sonography correctly identified the presence of renovascular disease in 41 of 44 patients with angiographically proven lesions, and renovascular disease was not identified in any patient free of disease. When single renal arteries were present (122 kidneys), renal duplex sonography provided 93% sensitivity, 98% specificity, 98% positive predictive value, 94% negative predictive value, and an overall accuracy of 96%. These results were adversely affected when kidneys with multiple (polar) renal arteries were examined. Although the end diastolic ratio was inversely correlated with serum creatinine (r = -0.3073, p = 0.009), low end diastolic ratio in 35 patients submitted to renovascular reconstruction did not preclude beneficial blood pressure or renal function response. We conclude from this analysis that renal duplex sonography can be a valuable screening test in the search for correctable renovascular disease causing global renal ischemia and secondary renal insufficiency (ischemic nephropathy). Renal duplex sonography does not, however, exclude polar vessel renovascular disease causing hypertension alone nor does it predict hypertension or renal function response after correction of renovascular disease.