Tricuspid valve replacement using a cryopreserved mitral homograft. Surgical technique and initial results.

BACKGROUND AND AIM OF THE STUDY: The surgical management of tricuspid valve endocarditis, especially in patients with positive serology for HIV and hepatitis C, is complicated by the inappropriateness of reconstruction and the late complications of mechanical prostheses and bioprostheses. Late results of mitral homograft replacement of the tricuspid valve have been satisfactory, but evidence of moderate and severe regurgitation appears in some patients. This report presents a novel approach to implantation of a mitral homograft in the tricuspid position. METHODS: Five patients with complications of native tricuspid valve endocarditis underwent mitral homograft replacement of the tricuspid valve, the homograft being implanted with the anterior leaflet orientated to the septum, the papillary muscles exteriorized and sutured to the right ventricular wall, the posteromedial muscle anteriorly, and the anterolateral muscle inferiorly. The annular attachment was reinforced with a rigid mitral annuloplasty ring in the anti-anatomical relationship. RESULTS: There was no early mortality. Among three patients available for echocardiographic assessment during the first year, regurgitation was absent in two cases, and trivial in one case. The latter patient died of a drug overdose after nine months. Two patients required insertion of atrioventricular pacemakers for complete heart block. CONCLUSION: This novel extension to the technique of mitral homograft replacement of the tricuspid valve for uncontrollable native endocarditis in drug abusers makes the procedure more technically feasible, and should be considered a procedure of choice.

Erythrocyte and polymorphonuclear cell transit time and concentration in human pulmonary capillaries.

Pulmonary capillary transit times were examined in patients who required lung resection by use of 99mTc-labeled macroaggregates (99Tc-MAA) and chromium-labeled erythrocytes (51Cr-RBC) to measure regional blood flow and volume in the resected lung. Cell flow (cells.ml-1.s-1) to each resected lung sample was determined by multiplying the number of polymorphonuclear leukocytes (PMN) per milliliter of circulating blood by the blood flow to that sample. Capillary blood volume was obtained by multiplying the morphometrically determined fraction of pulmonary blood in capillaries by the total 51Cr-RBC volume in each sample. Cell concentrations (cells/ml) in capillary blood were calculated morphometrically, and capillary transit times were obtained by dividing cell concentration by cell flow. The results show that PMN transit times were 60-100 times longer than the RBC transit times, with a 22% overlap between their distributions. We conclude that PMN are concentrated with respect to RBC in pulmonary capillary blood because of differences in their transit times and that these long transit times provide an opportunity for PMN-endothelial interactions.

Surgical management of pneumothorax in patients with acquired immunodeficiency syndrome.

Pneumocystis carinii pneumonia in a patient with acquired immunodeficiency syndrome may cause severe alveolar damage, resulting in pneumothoraces that are often bilateral, recurrent, and refractory to accepted methods of treatment. The clinical features, management, and follow-up results were assessed in 22 consecutive patients who presented with a pneumothorax and acquired immunodeficiency syndrome. Seventeen patients died within the time frame of this study. Their average survival time was 147 days. Five surviving patients have lived an average of 366 days. We proposed an algorithm to assist in the management of pneumothoraces in these patients. We concluded that pneumothorax in patients with acquired immunodeficiency syndrome is prognostic of short-term survival. The results in the treatment of pneumothorax in the patient with acquired immunodeficiency syndrome are related to the pathologic lesions of the lung that are associated with Pneumocystis pneumonia and not to the surgical treatment that is employed.

Effect of epinephrine on neutrophil kinetics in rabbit lungs.

The effect of epinephrine on neutrophil (PMN) kinetics in rabbit lungs was evaluated by measuring the retention of radiolabeled PMN's in the lung, the exchange rate between the marginated and circulating pools of PMN's, and the erythrocyte (RBC) transit time. Epinephrine treatment decreased RBC transit times and increased exchange rates in the regions with the shortest transit times but did not change the pulmonary recovery of radiolabeled PMN's. When regions of similar RBC transit time were compared, epinephrine did not affect PMN retention at short transit times but did produce greater retention at long transit times. These data suggest that the major effect of epinephrine was to increase the proportion of the lung having short RBC transit times and fast exchange rates between the marginated and circulating pools. However, this effect did not decrease the overall retention of PMN's most likely because it was balanced by recruitment of additional capillary segments, which increased PMN retention in regions with longer transit times.

Oleic acid-induced lung injury in rabbits: effect of fibrinogen depletion with Arvin.

The role of fibrinogen in the evolution of the increased permeability after oleic acid-induced lung injury was studied in New Zealand White rabbits. Animals depleted of fibrinogen by treatment with Malayan pit viper venom were compared with untreated rabbits immediately and at 1 and 24 h after injury. The increased permeability to albumin and elevated extravascular lung water (EVLW) associated with lung injury returned to control values by 24 h in untreated animals. Fibrinogen-depleted animals had a higher mortality (10/25 vs. 2/17, P less than 0.02) and showed a greater immediate increase in permeability to albumin that returned to control values at 1 and 24 h after injury, as well as trends toward elevated blood-free dry lung weight and larger increases in EVLW that persisted for 24 h. These findings indicate that fibrinogen-related proteins play an important role in controlling the microvascular injury that is produced by oleic acid. However, when these proteins are depleted, other mechanisms partially control the leak at later stages of the repair process.

Palliation after operation and after radiotherapy for cancer of the esophagus.

Because of the negligible cure rate in cancer of the esophagus, treatment is aimed principally at providing good palliation. This paper compares the degrees of palliation achieved after the two main treatments for symptomatic carcinoma of the esophagus. The degree of palliation was measured by a grading system designed to assess only the subjective responses of each patient. The results show that palliation as defined and measured in this study is the same after radiotherapy as after surgical excision. Since the expected survival is the same after radiotherapy as after operation, the expected morbidity and mortality of radiation are lower and radiotherapy may be used where operation is not possible, the authors suggest that radiotherapy is the better primary treatment for symptomatic squamous cancer of the esophagus.