Sakuzo Komatsu

Selective cerebral perfusion during operation for aneurysms of the aortic arch: A reassessment

Thirty-two consecutive patients with thoracic aortic aneurysms who required aortic arch reconstruction were operated on with the aid of extracorporeal circulation and selective cerebral perfusion between January 1986 and August 1990. For selective cerebral perfusion, blood was infused into both the innominate and left common carotid arteries at a rate of 10 mL.kg-1.min-1 using a single roller pump separately from the systemic circulation. In 9 patients treated before March 1987, the operations were performed without open aortic anastomosis (group 1), whereas in 23 patients treated from March 1987 onward we used open aortic anastomosis (group 2). The extracorporeal circulation and cardiac arrest times were significantly longer in group 2, but there was no significant difference in the cerebral perfusion time. Early death occurred in 1 patient in group 1 and 2 in group 2. No serious cerebrospinal neurological complications occurred in either group, and there were similar rates of postoperative hepatic and renal dysfunction in both groups. The present data suggest that selective cerebral perfusion and open aortic anastomosis are useful methods for thoracic aortic aneurysm operation requiring complex repair of the aortic arch.

Surgical outcome of aortic arch aneurysms using selective cerebral perfusion

The surgical results observed in 80 patients with aneurysms of the aortic arch who underwent an operation between January 1986 and the end of August 1992 were analyzed by multivariate analysis to identify predictors of high operative risk. All operations were performed using a cardiopulmonary bypass technique, blood cardioplegia for myocardial protection, and selective cerebral perfusion to prevent cerebral ischemia during aortic arch repair. The overall early (30-day) mortality rate was 16.3%. A severe stroke occurred postoperatively in 1 patient (1.3%). The 5-year survival rate was 73% +/- 5%, as determined by the Kaplan-Meier method. Multivariate analysis revealed that the presence of critical cardiopulmonary dysfunction preoperatively and the need for reoperation were significant independent predictors. Of the 63 (79%) patients who were free of these risks, only 3 (4.8%) died. The findings from the present study indicate that, currently, early mortality is relatively low for all patients who undergo operations for aneurysm of the aortic arch, unless they are in a critical condition preoperatively or unless they are undergoing a reoperation.

Comparative experimental study of cerebral protection during aortic arch reconstruction

BACKGROUND The optimal adjunctive method for cerebral protection during aortic arch repair remains controversial. METHODS Retrograde cerebral perfusion, selective cerebral perfusion, and hypothermic circulatory arrest were compared in terms of their effect on cerebral function of mongrel dogs using somatosensory evoked potentials. Brain temperatures were held at 20 degrees C for 90 minutes during cerebral perfusion or circulatory arrest and then rewarmed gradually to normal temperature. RESULTS Somatosensory evoked potentials completely disappeared as soon as retrograde cerebral perfusion or hypothermic circulatory arrest started and did not recover completely. In the selective cerebral perfusion group, it recovered in all cases. Only 2% of cerebral blood flow and about 3% of the cerebral metabolic rate for oxygen were obtained during retrograde cerebral perfusion compared with the preoperative value. The analysis of adenosine triphosphate and water content of the brain supported these results. CONCLUSIONS Retrograde cerebral perfusion had some advantage for cerebral protection compared with hypothermic circulatory arrest, but could not supply sufficient cerebral blood flow to maintain brain function. Selective cerebral perfusion was the safest method for arch reconstruction that requires cerebral protection for 90 minutes.

Experimental study on the optimum flow rate and pressure for selective cerebral perfusion

The optimum flow rate and pressure for selective cerebral perfusion during moderate hypothermia (25 degrees C) were investigated in 36 mongrel dogs. Cerebral perfusion was performed for 90 minutes at a flow rate of 100% (the physiologic flow rate), 50%, 25%, and 0%, or no flow (cerebrocirculatory arrest). Somatosensory evoked potentials were monitored to assess brain function. An excess lactate level was considered an index of anaerobic cerebral metabolism, and histopathologic evaluation was performed. Somatosensory evoked potentials showed no abnormalities at flow rates of 100% and 50%, but became abnormal in some dogs at 25% and in all dogs under no-flow conditions. The excess lactate level only increased at a no-flow rate, but not significantly. Histopathologic evaluation showed no ischemic changes at flow rates of 100% and 50%, but there were slight ischemic changes at 25% and severe ischemic damage at no flow. The mean carotid arterial pressure was 63.1 +/- 5.9, 39.8 +/- 6.2, 24.9 +/- 6.0, and 11.3 +/- 3.5 mm Hg at a flow rate of 100%, 50%, 25%, and no flow, respectively. These results suggest that the safe range of flow rates for cerebral perfusion during moderate hypothermia is more than 50% of the physiologic level with a carotid arterial pressure of about 30 mm Hg or more.

Total arch graft replacement in patients with acute type a aortic dissection

Treatment of acute type A aortic dissection with emergency total aortic arch graft replacement remains controversial. Between December 1988 and July 1993, 30 patients with this fatal disease underwent graft replacement of both the ascending aorta and total aortic arch on an emergency basis. All operations were performed with the aid of extracorporeal circulation, blood cardioplegia, selective cerebral perfusion, and open distal anastomosis. The overall early mortality rate was 23.3% (7 patients), but that in patients with complications with shock and renal/mesenteric ischemia was 57% and 66.7%, respectively. On the other hand, the mortality rate in the 23 patients (77%) in whom neither of these two risk factors was present was low (8.7%). The overall 4-year survival rate was 66.5% +/- 8.7%, and that for patients without these two risk factors was 87.0% +/- 7.0%. The present data suggest that simultaneous total arch replacement may be justified in selected patients with acute type A aortic dissection.

De Vega's annuloplasty for acquired tricuspid disease: Early and late results in 110 patients

From January 1978 through February 1989, 110 tricuspid annuloplasties (De Vegas procedure) were performed in association with mitral and combined mitral and aortic valve disease. Preoperatively, 106 (96%) of 110 patients were in New York Heart Association functional class III or IV. There were seven early deaths (6.3%), and 3 patients, 2 with mitral lesions and 1 with a combined lesion, died during a follow-up period of 3 to 52 months (mean follow-up, 22 months). Four patients (3.6%) required reoperation because of biological mitral valve failure at 5 to 8 years after tricuspid annuloplasty (mean period, 6.6 years). Twenty-three (62%) of 37 randomly selected patients evaluated by echocardiography and 14 (70%) of 20 patients evaluated by right ventriculography showed complete disappearance of tricuspid regurgitation after tricuspid annuloplasty in 1 to 18 months (mean period, 3.3 months). Seventy-seven (96%) of the survivors were in functional class I or II after tricuspid annuloplasty. The actuarial survival rate for the TAP series including early deaths was 85.8% +/- 7.4% at 10 years and the actuarial rate of freedom from reoperation on the tricuspid valve was 96.7% +/- 1.4%. Our surgical experience indicates that the De Vegas annuloplasty, as the method of first choice, is a simple, reliable procedure and resulted in improvement in 90% of patients with moderate to severe functional tricuspid regurgitation.

Extended aortic replacement for acute type a dissection with the tear in the descending aorta

OBJECTIVE There has been controversy as to the selection of surgical treatments for acute type A dissection with the tear in the descending thoracic aorta, a subtype of acute aortic dissection in which the limited tear is located distal to the left subclavian artery but the dissection extends retrogradely to the ascending aorta. METHODS Total replacement of the ascending aorta and aortic arch was performed in 12 patients with acute type A dissection with the tear in the descending thoracic aorta between March 1991 and the end of September 1995. The indications for total replacement of the ascending aorta and aortic arch were cardiac tamponade, acute aortic regurgitation, cerebral ischemia, and dilatation of the ascending aorta. The operation was performed with the aid of extracorporeal circulation, blood cardioplegia, selective cerebral perfusion, and open distal anastomosis. The surgical procedure used was total replacement of the ascending aorta and aortic arch with a graft provided with three limbs accompanied by resection of the intimal tear in the descending thoracic aorta. RESULTS Hospital death occurred in two patients (16.7%). In both, death was due to dissection/related complications of renal/mesenteric ischemia. The other 10 patients have had uneventful postoperative courses over a mean period of 24 months. CONCLUSIONS Total replacement of the ascending aorta and aortic arch accompanied by resection of an intimal tear distal to the left subclavian artery seems to be justified in selected patients with acute type A dissection with the tear in the descending thoracic aorta.

Surgical Treatment of Aneurysms of the Thoracic Aorta with the Aid of Partial Cardiopulmonary Bypass: An Analysis of 95 Patients

We retrospectively evaluated the surgical results in 95 patients with aneurysm of the thoracic aorta who were surgically treated using partial cardiopulmonary bypass (CPB) as an adjunctive method during the past 10 years. The cause of the aneurysm was atherosclerosis in 52% and dissection in 41%. Fifty-eight percent of the patients had an aneurysm of the entire descending thoracic aorta and 14 of these patients had a thoracoabdominal aneurysm. Emergency operation was performed in 16 patients (17%). There were 14 early deaths (14.7%) within one month after operation. Postoperative complications included renal dysfunction, partial paraplegia, and hemorrhage. Renal dysfunction occurred in 7 (7.8%) of the operative survivors; 2 of the 7 required hemodialysis. Partial paraplegia was observed in 2 patients undergoing total replacement of the thoracoabdominal aorta. Neither renal dysfunction nor paraplegia was related to the duration of aortic cross-clamping. Postoperative hemorrhage necessitating reopening of the chest occurred in 8 (8.9%) of the operative survivors. Partial CPB is useful in reducing the incidence of postoperative complications among patients undergoing aortic cross-clamping for a long period.

Surgical repair and long-term results in ruptured sinus of Valsalva aneurysm

Thirty-one patients with a ruptured sinus of Valsalva aneurysm (SVA) were operated on between January, 1961, and December, 1987. Twenty-five patients (81%) were in New York Heart Association (NYHA) Functional Class III or IV. Coexistent cardiac anomalies included a ventricular septal defect (VSD) in 16 patients (52%) and aortic valve regurgitation in 12 patients (39%). The ruptured SVA originated from the right coronary sinus in 29 patients (94%) and the noncoronary sinus in 2 patients (6%), and drained into the right ventricle in 30 patients (97%). In 6 patients treated recently, we used patches to repair the ruptured SVA and VSD through a double approach, thereby avoiding a ventriculotomy. This method resulted in no recurrent rupture or residual VSD postoperatively. There was one operative death (3%) and 4 late deaths (13%). Of the 26 surviving patients, 22 (85%) were in NYHA Class I at follow-up ranging from 6 months to 26.7 years (mean, 11.1 years). Actuarial survival at 25 years is 85.6 +/- 7.4% (mean +/- standard deviation). Repair of ruptured SVA with a patch through a double approach provides an excellent operative procedure and offers a long-term outcome.

Left ventricular pseudoaneurysm and intracardiac fistulas after replacement of mitral valve prosthesis.

Operation was performed on a 61-year-old woman with left ventricular pseudoaneurysm, left ventricular-right atrial fistula, and left ventricular-coronary sinus fistula after mitral valve replacement. The diagnostic and therapeutic approaches to these complications are described briefly, and the literature on intracardiac fistula after mitral valve replacement is reviewed.