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Biomedical subjects

C J Lambert

Publications and source records attributed to C J Lambert.

At least 19 recordsLinked to original sources

Isolated lung transplantation for end-stage lung disease: a viable therapy.

Since January 1990, we have performed 29 isolated lung transplantations in 28 patients with end-stage lung disease (12 single, 16 bilateral). Recipient diagnoses were: cystic fibrosis (11), chronic obstructive pulmonary disease (6), pulmonary fibrosis (6), eosinophilic granulomatosis (1), postinfectious lung disease (1), adult respiratory distress syndrome (1), and primary pulmonary hypertension (2). There have been four deaths, two in patients with pulmonary fibrosis and two in patients with primary pulmonary hypertension. Four patients have undergone transplantation while on ventilatory support for respiratory failure (2 with cystic fibrosis, 1 having redo lung transplantation with cystic fibrosis, and 1 with adult respiratory distress syndrome); all of these have survived. Six patients required cardiopulmonary bypass, which was associated with increased transfusion requirement. All patients 2 months after discharge have returned to an active life-style, except for 2 patients who currently await retransplantation. Preoperative pulmonary rehabilitation has resulted in significant improvement in exercise performance in all patients. Immunosuppression consists of cyclosporine, azathioprine, and antilymphoblast globulin (University of Minnesota), withholding systemic steroids in the early postoperative period. We have employed bronchial omentopexy in all but four transplants; there has been one partial bronchial dehiscence, two instances of bronchomalacia requiring internal stenting, and one airway stenosis. Cytomegalovirus disease has been seen frequently (15 cases), but has responded well to treatment with ganciclovir. Other complication shave included one drug-related prolonged postoperative ventilation, thrombosis of a left lung after bilateral lung transplantation requiring retransplantation, five episodes of unilateral phrenic nerve palsy after bilateral lung transplantation (4 resolved), and the requirement of massive transfusion (greater than 10 units) in 5 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Optimal timing of administration of a free radical scavenger in lung preservation.

The optimal timing of administration of free radical scavengers in lung preservation has yet to be determined. In previous studies, the oxygen free radical scavenger dimethylthiourea (DMTU) has improved pulmonary function when added to Eurocollins flush solution at the time of lung harvest and infused at the time of lung reimplantation. To determine when DMTU must be administered in order to preserve lung function most effectively, 16 dogs underwent lung allotransplantation. Donor lungs were flushed with modified Eurocollins solution (50 ml/kg) and stored for 12 hr at 4 degrees C. DMTU was either added to the flush solution (5 g) or infused (20 g over 2 hr) at the time of reimplantation. Investigators were blinded to the time of DMTU administration. The contralateral pulmonary artery was ligated after a 1-hr stabilization period. Measurements were recorded for 8 hr while keeping FiO2 constant at 40%. The flush group demonstrated significantly improved survival and oxygenation compared with the infusion group. The mortality rate was 50% in the infusion treatment group, while no deaths occurred in the flush animals. Lung function is adequately preserved after 12-hr storage when DMTU is administered in the flush solution at the time of harvest. It would appear that oxygen free radical scavengers must be present in lung tissue during storage in order to be effective.

Animals

Enhanced pulmonary function using dimethylthiourea for twelve-hour lung preservation.

Current preservation techniques for lung transplantation limit ischemic time to 6 hours. The purpose of this study was to evaluate the ability of dimethylthiourea, a low molecular weight free radical scavenger, to prolong this interval. An in vivo canine transplantation model was used to assess lung function. At harvest and after circulatory arrest, the donor lung was flushed with modified Euro-Collins solution (50 mL/kg). In a blinded fashion, dimethylthiourea (5 g) or saline solution was added to the flush solution at harvest and also infused (20 g over 2 hours) at reimplantation. Harvested lungs were stored for 12 hours at 4 degrees C. Allotransplantation was performed in recipient dogs ventilated with 40% O2. After 1 hour, the contralateral pulmonary artery was ligated, forcing the dog to be dependent on the transplanted lung. Twelve dogs were studied, with 6 randomly assigned to each treatment group in a blinded fashion. Measurements were recorded for 8 hours, keeping the inspired oxygen fraction constant at 0.40. All dimethylthiourea-treated dogs survived the observation period, whereas one third of the dogs that received saline solution died. Dimethylthiourea-treated dogs had significantly greater arterial oxygen tension and significantly less pulmonary vascular resistance compared with control animals. These results suggest that treatment of the lung with a free radical scavenger (dimethylthiourea) improves pulmonary function after reimplantation in a canine model after 12-hour hypothermic storage.

Animals

A strategy to increase the donor pool: use of cadaver lungs for transplantation.

A shortage of suitable donors is a serious obstacle to the widespread application of isolated lung transplantation for end-stage lung disease. We hypothesized that lung tissue likely remains viable for a sufficient period of time to allow for safe postmortem retrieval of lungs for transplantation. Studies were conducted in a nonsurvival model of canine lung allotransplantation. Donor animals were sacrificed, and subsequent lung harvest was delayed for 1 hour, 2 hours, or 4 hours. Pulmonary retrieval was then performed in a standard fashion, flushing the lung block with modified Euro-Collins solution. Lungs were then stored for 4 hours before single allotransplantation. Recipient animals were maintained anesthetized, and followed up for 8 hours. By occlusion of the pulmonary artery and bronchus to the native lung, recipient animals were forced to survive solely on the transplanted lung, with a constant inspired oxygen fraction of 0.40. All 5 recipient animals of 1-hour cadaver lungs survived the 8-hour observation period with excellent hemodynamics and gas exchange. Two of 5 recipients of 2-hour cadaver lungs survived the observation period, whereas a third animal survived for 5 hours with excellent gas exchange. One of 4 animals transplanted with a 4-hour cadaver lung survived the observation period. Retrieval of lungs from cadavers whose hearts are not beating may prove to be a safe and effective method to increase the pulmonary donor pool.

Animals

Major hepatic resections: a 10-year experience with emphasis on special problems.

From 1976-1985, 32 patients underwent major hepatic resection at the University of Mississippi Medical Center. This experience was reviewed to determine the relationship of blood loss, postoperative hyperbilirubinemia, and the performance of concomitant surgical procedures to operative mortality, local tumor recurrence, and long-term survival. There were no deaths among 16 elective resections. Of 16 patients undergoing emergency resections, seven died (43.8%). The mortality rate correlated strongly with intraoperative transfusion of more than 10 units of blood and with postoperative hyperbilirubinemia. Performance of additional procedures increased mortality significantly after emergency, but not elective, hepatic resection. Median survival was 53.4 months in patients resected for hepatoma and 33.5 months in those patients resected for metastatic colon lesions. Local recurrence in a patient with hepatoma was managed by resection at 13 months, with no evidence of further recurrence at 69 months.

Adolescent

Splenic artery aneurysm. A rare cause of upper gastrointestinal bleeding.

Most splenic artery aneurysms (SAAs) are asymptomatic at the time of discovery, being found incidentally during laparotomy or angiography. SAAs are most likely to be found in multiparous women. Complications of SAAs include free intraperitoneal rupture and erosion into abdominal viscera or vessels, with resultant high mortality. Surgery is indicated for symptomatic, enlarging, or large (greater than or equal to 2.5 cm) SAAs as well as any SAA found in women of childbearing age. Treatment of such aneurysms depends on the location and includes excision, ligation, and splenectomy. The present report presents the first known case, to our knowledge, of SAA presenting with massive upper gastrointestinal bleeding from erosion into the stomach in a nulliparous woman. Prompt surgical intervention resulted in correct diagnosis and patient survival.

Aged

The treatment of postperfusion bleeding using epsilon-aminocaproic acid, cryoprecipitate, fresh-frozen plasma, and protamine sulfate.

The evaluation of excessive hemorrhage was carried out in 774 patients after cardiopulmonary bypass. Excessive hemorrhage was defined in any adult patient as chest tube drainage of more than 600 ml within the first eight hours after operation. Using the prothrombin time, partial thromboplastin time, fibrinogen level, and tri-F titer tests, it was possible to differentiate medical from surgical bleeding. Hyperfibrinolytic bleeding was the most frequently identifiable coagulation disorder and occurred in 159 patients (20%). All these patients were successfully treated with Amicar (epsilon-aminocaproic acid) alone, or with Amicar supplemented with cryoprecipitate or fresh-frozen plasma. Three patients (0.4%) were noted to have residual heparin and required additional protamine sulfate. Five patients (0.6%) had normal coagulation studies and required immediate reexploration. The overall blood consumption per patient was 2.1 units of packed cells. Whole blood and platelets were not used.

Aminocaproates

Treatment of severe coronary artery disease with 5, 6, and 7 saphenous vein bypasses: review of 131 consecutive patients.

One hundred thirty-one consecutive patients who received 5, 6, and 7 bypass grafts are analyzed. Ages ranged from 31 to 74 years. The male-to-female ratio was 7:1. As an indication of severity of disease, 25% were classified as having impending myocardial infarction and 46.6% were classified in New York Heart Association Functional Class IV. Left ventricular function was impaired in 37.4%, and 30% of the patients had left main coronary obstruction. Nonfatal perioperative myocardial infarction occurred in 4.6%. The hospital mortality was 3%. One hundred percent follow-up (5 to 55 months) revealed 4 late deaths, 3 presumably of cardiac origin. Only 7 patients in the postoperative follow-up group have complained of angina; 1 has since undergone successful reoperation.

Adult

Embolization of disc occluder of a Wada-Cutter mitral prosthesis with survival.

The second recorded survivor following emergency prosthesis replacement after embolization of the Teflon disc occluder of a Wada-Cutter mitral valve is reported. Difficulties encountered while attempting to locate the missing occluder are presented and a useful operative technique for aortic control is described. A plea is made for incorporation of a radiopaque material during manufacture of all future valve poppets.

Adult

Myocardial revascularization in patients with poor ventricular function.

Eighty patients with evidence of impaired ventricular function by ventriculography were reviewed. On the basis of the ejection fraction, these patients were divided into three groups. Those with ejection fractions less than 0.2 were considered in very poor condition, those with ejection fractions of 0.2 to 0.4 were considered in poor condition, and those with ejection fractions with between 0.4 and 0.6 were considered fair. Suitability of vessels for bypassing and the presence or absence of collateral cirulation on the cinearteriograms was also noted for possible influence on result. Operative mortality rate in patients having complete repair, defined as bypassing all major vessels with significant obstruction, was 7 per cent. In 26 patients having incomplete repair, the operative mortality was 30 per cent. However, the late mortality rate was not favorably influenced by complete repair, 75 per cent are in improved or good clinical condition, as compared with 65 per cent in the incomplete repair group. As patients with impairment of ventricular contractility are at high risk, it is believed that they should continue to be evaluated on an individual basis for bypass surgery and not categorically denied treatment.

Adult