Kotaro Suehiro

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.

Staged repair of a thoracoabdominal aortic aneurysm with mesenteric ischemia using the reversed elephant trunk technique

Improvements in surgical techniques, and adjuncts for spinal cord protection and perioperative care have resulted in decreased morbidity and mortality in repair of thoracoabdominal aortic aneurysm (TAAA). However the surgical treatment of TAAA of extent II is still associated with high mortality, especially in patients with preoperative co-morbidities. We report a successful staged repair of extent II TAAA using the reversed elephant trunk technique for a patient with ischemic colitis.

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.