Makoto Mohri

Posttransplant function of a nonbeating heart is predictable by an ex vivo perfusion method

BACKGROUND We attempted to predict the posttransplant cardiac function of nonbeating donor hearts. METHODS A total of 13 dogs were studied. Hearts were left in situ for 45 minutes after cardiac arrest caused by exsanguination. Hearts were then excised and reperfused in an ex vivo perfusion apparatus after 60 minutes of warm ischemia to test whether they could eject against an 80 mm Hg afterload from a preload of 10 mm Hg. Thereafter, all hearts were transplanted orthotopically. RESULTS Four of 13 hearts were able to eject in the apparatus (group A). However, the other nine hearts could not eject under the defined conditions (group B). All four hearts in group A showed good posttransplant hemodynamics (systolic arterial pressure > 80 mm Hg with mean left atrial pressure < 10 mm Hg) without dopamine. However, none of nine hearts in group B could support the circulation without dopamine. CONCLUSIONS Nonbeating donor heart function evaluated in the perfusion apparatus predicts posttransplant heart function. This method may be applicable for selection of transplantable hearts from nonbeating heart donors.

Late aortic root redissection following surgical treatment for acute type A aortic dissection using Gelatin-Resorcin-Formalin glue.

OBJECTIVES Although Gelatin-Resorcin-Formalin (GRF) glue is widely used in surgery for acute aortic dissection, late complications possibly due to the glue, such as late aortic root redissection, have also been reported. We have experienced similar complications, some of which required redo surgeries, and these cases are reviewed. METHODS Twenty-six consecutive patients who underwent surgery for acute type A aortic dissection using GRF glue, from December 1996 to February 2001, were retrospectively studied, with a special focus on any late complications and any reoperation. RESULTS Of the 21 patients who survived and were followed as outpatients, false aneurysms were found in 5 patients (21%) at 24-42 (mean 34) months following the initial surgery. Of these, 2 patients required resternotomy because of the increasing aneurysm diameter. In both cases, the aortic root was redissected at the site of the GRF glue use where the anastomosis between the aortic root and the prosthesis had widely opened and had become the aneurysm entry point. Significant aortic regurgitation was noticed in 3 patients (14%, 1 of whom showed a false aneurysm), and 2 of these underwent reoperation for aortic root redissection. CONCLUSIONS A high incidence of aortic root redissection with false aneurysm and/or aortic insufficiency was found following the surgery for acute aortic dissection using GRF glue. These patients should be carefully followed for years after surgery.

Nicorandil ameliorates posttransplant dysfunction in cardiac allografts harvested from non-heart-beating donors.

OBJECTIVE Warm ischemia is a major cause of cardiac allograft dysfunction in non-heart-beating donors (NHBDs). We evaluated the cardioprotective effects of nicorandil, an adenosine triphosphate-sensitive potassium channel opener, on the early posttransplant left ventricular (LV) function of hearts harvested from asphyxiated canine NHBDs. METHODS Hypoxic cardiac arrest was induced in 12 donor dogs. In 6, nicorandil was administered intravenously at 100 micrograms/kg + 25 micrograms/kg/min after respiratory arrest and hearts were preserved with nicorandil-supplemented cardioplegic solution (nicorandil group). The remaining 6 did not receive nicorandil at any time during the experiment (control group). Hearts were orthotopically transplanted after a mean myocardial ischemic time of 4 hours. RESULTS All 12 recipients were weaned from cardiopulmonary bypass without inotropic support. In the control group, posttransplant cardiac indices and left ventricular end-systolic pressure (LVESP) decreased significantly, while LV max-dP/dt and Tau increased over pretransplant values. No differences were seen in parameters between pretransplant and posttransplant values in the nicorandil group. Posttransplant cardiac indices, LVESP, and LV max + dP/dt were higher in the nicorandil group than in controls, while posttransplant LV max-dP/dt in the nicorandil group was lower. CONCLUSIONS Our results indicate that pretreatment with nicorandil during hypoxic perfusion before cardiac arrest and subsequent preservation with nicorandil-supplemented cardioplegia ameliorates early posttransplant LV dysfunction of hearts harvested from asphyxiated NHBDs.

Successful repair of critical aortic stenosis with coarctation on the first day of life

Successful open aortic valvotomy and end-to-end anastomosis were performed to the patient with critical aortic stenosis and CoA on the first day of life. A fetus was diagnosed as aortic stenosis and coarctation by fetal echocardiography at 29 weeks of gestation. The mother was transferred to our hospital at the onset of labor and delivered vaginally at 40 weeks of gestation. Soon after the birth, the newborn, birth weight 2630 gram, female, underwent echocardiography by pediatric cardiologists which demonstrated the aortic orifice of 5.1 mm in diameter and thickened cusps with poor mobility. Transaortic pressure gradient measured by Doppler echocardiography was 111 mmHg and the left ventricular wall motion was hyperdynamic without any signs of endocardial fibroelastosis. Prostaglandin E1 administration was started to maintain systemic circulation and the hemodynamic status has been stable before surgery. On her first day of life, the operation was performed using cardiopulmonary bypass with moderate hypothermia. Isolated cerebral and myocardial perfusion technique was applied during the repair of coarctation of the aorta. The open aortic valvotomy with resection of myoxomatous nodules on leaflet edges effectively released pressure gradient across the aortic valve without regurgitation. Post-operative course was uneventful and she discharged at 28th day after surgery. We conclude early diagnosis including fetal echocardiography and early repair would lead the better surgical outcome to the neonates with critical aortic stenosis.