Perfusatory recovery of the grafted lung during convalescence from acute rejection.

The aim of this study was to evaluate whether or not perfusatory recovery of the grafted lung occurs is the early stage of convalesce from acute rejection following a single lung transplantation. Eight adult mongrel dogs underwent an allotransplantation of the left lung with treatment of 10 mg/kg cyclosporine and 4 mg/kg azathioprine. Doppler flow probes were placed to the ascending aorta and the left pulmonary artery. Immunosuppressant therapy was discontinued to induce rejection after postoperative day 14. When the left pulmonary artery flow rate (l-PAFR) decreased to less than 20%, methylprednisolone (20 mg/kg) was administered for 3 days along with a resumption of cyclosporine and azathioprine. Pulmonary circulation and chest roentgenograms were evaluated every day through the rejection episode. An open lung biopsy was also performed in each dog to obtain specimens of the grafts and native lungs for histologic examination. When l-PAFR decreased to less than 20%, mild acute rejection was found in all dogs. l-PAFR increased significantly on the third day after methylprednisolone treatment. Thereafter, a histologic examination revealed minimal acute rejection in one dog and no abnormality in seven dogs. The perfusatory recovery of the grafted lung was thought to reflect the histological change in the course of convalescence.

Pulmonary circulatory parameters as indices for the early detection of acute rejection after single lung transplantation.

We investigated the relationship between the changes in the pulmonary blood flow and histology during acute rejection following single lung transplantation. In single lung transplantation using adult mongrel dogs, immunosuppression with cyclosporine and azathioprine was discontinued after postoperative day 14 to induce rejection. Doppler flow probes were placed adjacent to the ascending aorta and the left pulmonary artery to measure the blood flow on a daily basis. In addition, chest roentgenograms were also examined daily. The pulmonary pressure was measured using a Swan-Ganz catheter prior to and following the induction of rejection. Open lung biopsies were performed when the left pulmonary artery flow decreased to half of the prerejection value. The pulmonary artery flow decreased to 14.3% of the aortic flow 5 days after the discontinuation of immunosuppression. The graft pulmonary vascular resistance increased significantly compared to the prerejection values (P < 0.001). This was not accompanied by any abnormalities on chest roentgenography. The histology was consistent, with marked perivascular lymphocytic infiltration with little alveolar or interstitial changes. During rejection, the increased pulmonary vascular resistance in the graft was probably the result of perivascular inflammatory cell infiltration, which was seen prior to changes on chest roentgenography. Changes in the left pulmonary artery flow and histology thus appear to be closely correlated in the early stages of acute rejection.

[Effect of reimplantation response on recipient pulmonary hemodynamics in single lung transplantation].

Until now, reimplantation response (RR) has been thought to be a transient dysfunction of the transplanted lung in single lung transplantation. How does RR influence on the native lung in single lung transplantation? We studied the influence of RR to the native lung with 20 dogs which were divided separated into 3 groups. In group I (6 dogs) and II (6), left lung allotransplantation without immunosuppression was performed. In group II, PGI2 was administered to the donors at 1 microgram/kg/min for 60 minutes iv drip infusion during lung extraction and super oxide dismutase (SOD) was administered to the recipients at 20 mg/kg just before reperfusion of the transplanted lung. In group III (8), allotransplantation with immunosuppression (CYA 20 mg/kg, AZ 4 mg/kg) was done using PGI2 and SOD in the same way as group II. In all groups doppler flow probes were attached to the ascending aorta and left pulmonary artery. For over 1 week, pulmonary hemodynamics was evaluated. In group I pulmonary arterial pressure increased up to 38.7 +/- 19.7 mmHg on 3 postoperative day, which showed significant difference (p < 0.05) from group II. An increase in vascular resistance of the transplanted lung was recognized right after transplantation in the both groups (0.212 +/- 0.058 mmHg/ml/kg to 0.487 +/- 0.114 in group I, 0.207 +/- 0.072 to 0.407 +/- 0.172 in group II). However, vascular resistance of the right lung increased in group I against group II right after transplantation (0.182 +/- 0.116 to 0.367 +/- 0.195 in group I, 0.183 +/- 0.116 to 0.214 +/- 0.149 in group II), which showed significant difference (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

[Mitral valve replacement and right ventricular outflow repair for hypertrophic obstructive cardiomyopathy].

A 44-year-old male with hypertrophic obstructive cardiomyopathy (HOCM) was operated on. He was in NYHA class III with a chief complaint of exertional dyspnea refractory to medical treatment. Echocardiography showed asymmetric septal hypertrophy and systolic anterior movement of the mitral valve, which caused obstruction of the left ventricular outflow tract. It also showed obstruction of the right ventricular outflow tract due to septal hypertrophy. Cardiac catheterization showed a systolic pressure gradient of 70 mmHg at the LV outflow tract and that of 30 mmHg at the RV outflow tract. He underwent mitral valve replacement and patch enlargement of the RV outflow tract. Postoperative course was uneventful. Postoperative catheterization showed a remarkable decrease of pressure gradient to 10 mmHg at the both outflow tracts.