Takaaki Sugita

Predictors of residual tricuspid regurgitation after mitral valve surgery.

BACKGROUND Whether preoperative tricuspid regurgitation (TR) will regress or progress late after surgery is unknown. The aim of this study was to evaluate predictors of significant TR late after mitral valve surgery. METHODS A retrospective analysis was performed on a total of 174 patients who underwent mitral valve surgery without tricuspid valve surgery. Preoperatively, 46 patients (26%) had 2+ TR, and 128 patients (74%) had 1+ or less TR. Postoperative 3+ TR was considered significant TR. Variables were used to evaluate predictors of TR development by univariate or multivariate analysis. RESULTS The mean follow-up was 8.2 years (range 1.0 to 14.5 years) after surgery. There was progressive TR (3+ or more) in 28 patients (16%) during the follow-up period. In univariate analysis, atrial fibrillation, rheumatic etiology, huge left atrium, left ventricular dysfunction, and preoperative 2+ TR were significant risk factors for TR development. Multivariate analysis identified preoperative 2+ TR, atrial fibrillation, and huge left atrium as statistically significant predictors for late TR after surgery. CONCLUSIONS Aggressive repair of accompanying TR should be undertaken at the time of initial surgery in patients with huge left atrium or atrial fibrillation, even if preoperative TR is 2+.

Monitoring of regional cerebral oxygenation by near-infrared spectroscopy during continuous retrograde cerebral perfusion for aortic arch surgery

OBJECTIVE To assess the value of monitoring of regional cerebral oxygen saturation (rSO2) during aortic arch surgery using continuous retrograde cerebral perfusion (CRCP) in conjunction with profound hypothermic circulatory arrest (HCA). METHODS The rSO2 of 12 consecutive patients was monitored non-invasively using near-infrared spectroscopy (NIRS) and the data were analyzed statistically. RESULTS The mean duration of HCA with CRCP was 62-/+14.1 min. The mean CRCP flow rate was 226+/-163 ml/min. Surgical outcomes were favorable with only a single hospital death (8.3%). However, the rSO2 decreased gradually in all patients during HCA, even combined with CRCP, and fell to 46+/-8.7% on average. It did not change so greatly before HCA and returned finally to its initial level at the end of re-warming. Only one patient developed a permanent neurologic deficit; this patient showed the greatest decrease of rSO2 from 56% to 29% after the longest HCA of 88 min. Two parameters, End-rSO2 (the ratio of post- to pre-HCA rSO2) and delta-rSO2 (the rate of decrease from preto post-HCA rSO2) were obtained since the initial values of rSO2 before surgery differed. There were linear correlations between the CRCP flow rate and each of these two parameters. A multiple regression analysis also revealed a linear equation relating the parameters, which allowed prediction of the safe duration of HCA in different conditions of CRCP and a more favorable adjustment of the CRCP condition in each patient. CONCLUSIONS The study suggests that the combination of HCA and CRCP has a limit of safe duration in spite of its potential usefulness for brain protection, and that rSO2 monitored by NIRS is useful in testing for adequate brain protection. It is hoped that monitoring of rSO2 can facilitate prediction of the safe duration of HCA with CRCP and a more favorable adjustment of CRCP.

Nasal mask bilevel positive airway pressure ventilation for diaphragmatic paralysis after pediatric open-heart surgery.

A 2-year-old boy underwent surgical repair of tetralogy of Fallot. Topical cooling of the heart with ice slush was used during the operation. Diaphragmatic paralysis occurred after the operation, inducing severe respiratory distress. To avoid repeated intubation and tracheostomy, the patient was placed on nasal mask bilevel positive airway pressure (BiPAP) ventilation. After ventilatory support with BiPAP for 40 days, the patient recovered spontaneously from the paralysis. No sedation was required during this time. This report illustrates the usefulness of BiPAP for a pediatric patient with diaphragmatic paralysis after cardiac surgery.

Aortic arch repairs through three different approaches.

OBJECTIVES The outcome of aortic arch repairs by means of three different approaches between 1990 and January 2000 was reviewed. METHODS In total 39 patients aged 71.5+/-6.2 years were operated on. The three different surgical approaches depended on the anatomical positions of the aneurysms and on their proximal or distal extension; a median approach was employed in 23 patients, whereas a left postero-lateral approach was used in eight patients. More recently, in eight cases a left antero-lateral approach was applied. All patients underwent open aortic anastomosis without any clamp on or around the aortic arch. During the procedure, the brain was protected by a combination of profound hypothermic circulatory arrest and several techniques of retrograde cerebral perfusion. RESULTS Permanent cerebral dysfunction occurred in four patients: two in the median approach and two in the left postero-lateral approach. There were two hospital deaths (5.3%) and six late deaths, all of which belonged either to the median group or to the postero-lateral group. The antero-lateral approach did not produce any cerebral dysfunction, early death, or late death. CONCLUSIONS The outcome of aortic arch repairs using profound hypothermic circulatory arrest and variable techniques of retrograde cerebral perfusion, by means of three different approaches, was satisfactory. Of the three approaches, the antero-lateral approach can be employed easily, whether aneurysms extend proximally or distally.

Surgical treatment of five patients with aortobronchial fistula in the aortic arch

Aortobronchial fistula (ABF) is a rare condition that is almost always fatal in the absence of prompt and proper treatment. However, treatment remains challenging, particularly in the aortic arch. We present six operations for 5 such patients, in which no in-hospital deaths occurred. One patient with mycotic aneurysm died suddenly 10 months postoperatively. Another patient required reoperation 5-months after operation due to additional ABF. No pseudoaneurysms or graft-related complications were observed in the remaining patients. In patients with ABF, performance of operations as soon as possible after onset and minimal dissection of adherent lung tissue appear to improve outcomes.

β-blocker therapy in patients after aortic valve replacement for aortic regurgitation

BACKGROUND beta-blocker therapy for dilated or ischemic cardiomyopathy is now an accepted and effective treatment. However, little is known about its efficacy in patients with postoperative impaired left ventricular function. This retrospective study was designed to assess the effects of beta-blocker therapy in patients after aortic valve replacement (AVR) for aortic regurgitation (AR). METHODS A total of 59 patients who underwent AVR for chronic AR were assigned to four groups. Twelve patients were treated with both ACE inhibitors and beta-blockers, 12 patients with only ACE inhibitors, eight patients with only beta-blockers, and 27 patients without beta-blockers or ACE inhibitors. A postoperative echocardiographic study was performed one year after surgery. RESULTS The heart rate was significantly reduced in patients with beta-blockers despite the use of ACE inhibitors after surgery. Postoperative left ventricular volume was more significantly decreased in beta patients than in non-beta patients despite the use of ACE inhibitors. There were also significant reductions in left ventricular mass index in ACE+beta patients compared to ACE+non-beta patients. However, there were no significant differences in NYHA functional class and survival rate between beta patients and non-beta patients. CONCLUSIONS beta-blocker therapy may improve cardiac performance by reducing cardiac volume and mass in patients with impaired LV function after AVR for AR.

Repeated procedure after radical surgery for tetralogy of Fallot

BACKGROUND Although the immediate results of radical operation for tetralogy of Fallot are excellent, long-term follow-up has shown that the number of repeated procedures has increased in many institutions. We describe patients who underwent a second or third procedure after radical operation for tetralogy of Fallot. METHODS Between April 1981 and August 1996, we operated on 44 patients for the second time and on 4 for the third time after radical operation for tetralogy of Fallot. Indications for a second and third procedure included right ventricular outflow tract obstruction in 38 patients, infective endocarditis in 4, and isolated residual ventricular septal defect in 3. RESULTS One patient died after concomitant replacement of the pulmonary and tricuspid valves. Three patients who underwent sternotomy more than twice (before the second or third operation) underwent accidental cardiovascular trauma during this procedure (30%). Moreover, when patients underwent more than two sternotomy procedures before the repeated operation for tetralogy of Fallot, the total bypass time, interval between cessation of the cardiopulmonary pump to completion of the operation, amount of blood transfusion, and length of intensive care unit stay were significantly higher compared with those who underwent less than two sternotomy procedures (p < 0.05). Right ventricular outflow tract obstruction was the main indication for a second operation. After the second operation for right ventricular outflow tract obstruction in 35 patients, the preoperative right ventricle to left ventricle pressure ratio decreased significantly (from 0.75 +/- 0.13 to 0.51 +/- 0.12; p < 0.0001). However, the right ventricle to left ventricle pressure ratio did not significantly decrease in patients who underwent a third procedure to treat right ventricular outflow tract obstruction. CONCLUSIONS The surgical results of a second procedure after radical operation for tetralogy of Fallot were acceptable. However, the risk of accidental cardiovascular trauma during dissection was high among patients who underwent sternotomy more than twice before repeat operation.

Surgery for acute type A aortic dissection using retrograde cerebral perfusion.

OBJECTIVE We reviewed the surgical management of acute type A aortic dissection between 1989 and 1998. METHODS Subjects were 28 consecutive patients (mean age: 61.8 +/- 10.7 years) with acute type A aortic dissection were studied. The mean duration between aortic dissection onset and surgery was 17.5 +/- 17.0 hours. In surgery, aortic pathology and flow patterns in dissected aortic channels were evaluated using transesophageal and epiaortic echo. Simple, safe combination of profound hypothermic circulatory arrest with retrograde cerebral perfusion and open aortic anastomosis was used for brain protection. Hypothermic circulatory arrest was 46.9 +/- 24.8 minutes. Aortic repair consisted in ascending aortic replacement in 5 patients, with hemiarch repair in 17, and total arch repair in 6. Intimal tears were resected in all but 2 patients. Concomitantly resuspension of the aortic valve was done in 9 and aortic root replacement in 2. RESULTS No operative (30-day) deaths occurred, although 2 died from unrelated hepatic failure during hospitalization or late-stage pancreatic cancer in the late stage. In cerebral sequellae, 1 patient suffered a stroke and 2 patients developed temporary neurologic dysfunction. CONCLUSION Our experience demonstrated that the simplified conjunction of hypothermic circulatory arrest with retrograde cerebral perfusion and open aortic anastomosis, associated with real-time assessment by transesophageal and epiaortic echo, is safe and useful during emergency aortic repair for acute type A aortic dissection.

Early and mid-term outcomes of cardiac and thoracic aortic surgery in over-75-year-olds with postoperative quality of life assessment

The early and mid-term outcomes of cardiac and thoracic aortic surgery were reviewed in seventy-two consecutive patients aged 75 years and older, together with assessment of postoperative quality of life. Twenty-six patients had ischemic heart disease, twenty had valvular heart disease, one had congenital heart disease, and twenty-five had thoracic aortic aneurysm. Twenty-five (34.7%) required an emergency operation. There were 6 early deaths (8.3%) and 11 late deaths (17.2%), of which the emergency cases had higher mortality of 5 early deaths (20.0%) and 3 late deaths (15.0%). In particular, most cases with a ruptured thoracic aortic aneurysm died eventually from various complications including neurological dysfunction. The others with a non-ruptured aneurysm also had atherosclerotic aortic or arterial lesions which caused a lethal cerebrovascular accident or ischemic heart disease. The quality of life of 51 of 53 survivors was assessed using the Rosser and Watts index being based on disability and distress scores. The response was satisfactory--the disability score was 2.6 +/- 1.9 and the distress score was 1.4 +/- 0.4. The patients with a thoracic aortic aneurysm had worse quality of life scores than those of the ischemic heart disease or valvular heart disease patient-groups because of various perioperative complications. Our experiences demonstrate that the results including the postoperative quality of life following cardiac and aortic surgery in the elderly is satisfactory except for emergency cases. The results would prompt us to operate, if possible, electively in their stable conditions, even on elderly over-75-year-olds.

Successful repair of an aortoesophageal fistula caused by a thoracic aortic aneurysm: Report of a case

Aortoesophageal fistula occurring as a complication of a thoracic aortic aneurysm is difficult to repair because of the contaminated surgical field. We report the case of a 67-year-old man in whom an aortoesophageal fistula developed secondary to a dissecting thoracic aortic aneurysm. We performed in situ graft repair of the aneurysm, then covered the site with omentum and resected the esophagus to prevent graft infection. About 5 months later, the esophagus was reconstructed subcutaneously using an ascending colon pedicle. The patient recovered well and has resumed leading a normal life.