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There is debate about how patients should be managed when malignant involvement of mediastinal lymph nodes is encountered at the time of lung resection. A comprehensive review of the literature demonstrates that differences in which outcomes are reported and how extensively patients were staged preoperatively explain much of the conflicting data. Certain negative and positive prognostic factors can be defined, but in general the outcomes justify proceeding with resection unless it is clear that disease will be left behind. Reasonable arguments can be made that the approach should include a mediastinal lymph node dissection and adjuvant therapy.

Bowel metastasis and perforation in patients with non-small cell lung cancer is rare. Bevacizumab has emerged as a new therapy in the treatment of metastatic non-small cell lung cancer. Bowel perforation associated with its use has been described in colon and ovarian cancers. The exact mechanism by which perforation occurs is under debate, and many theories exist. In this report, we present the first known case of visceral perforation in a patient with metastatic non-small cell lung cancer after treatment with bevacizumab.

Objectives: We reviewed our experience with lung transplant for cystic fibrosis (CF) over a 10-year period to identify factors influencing long-term survival., Methods: One hundred and twenty-three patients with CF have undergone 131 lung transplant procedures at our institution; 114 have had bilateral sequential lung transplants (DLTX) and nine have had bilateral lower lobe transplants from living donors. Three patients had retransplant for acute graft failure, and five had late retransplant for bronchiolitis obliterans syndrome (BOS). Kaplan-Meier survival was calculated for the entire cohort and for subsets at higher risk of death to determine factors predicting a better outcome., Results: Actuarial survival for the entire group of DLTX CF patients was 81% at 1 year, 59% at 5 years, and 38% at 10 years. Lobar transplant was associated with a poorer survival (37.5% at 1 and 5 years). Among DLTX patients, colonization with Burkholderia cepacia was present in 22 patients and was associated with poorer outcome (1- and 5-year survival 60 and 36% in B. cepacia patients vs. 86 and 64% in non-cepacia patients). DLTX patients younger than age 20 (n=22) had a similar survival to patients age 20 or older (n=90). Being on a ventilator at the time of transplant was not associated with poorer survival (n=8). BOS affects increasing numbers of survivors with time. Five CF patients have been retransplanted due to BOS with one operative death and 1-year survival of 60%., Conclusions: DLTX has acceptable long term survival in CF adults and children with end stage disease. CF patients colonized with B. cepacia have a worse outcome but transplantation is still warranted.

Background: A modified Phase I/II trial was conducted evaluating the incorporation of three-dimensional conformal radiation therapy into a strategy of sequential and concurrent carboplatin/paclitaxel in Stage III unresectable nonsmall cell lung carcinoma (NSCLC). The dose of thoracic conformal radiation therapy (TCRT) from 60 to 74 gray (Gy) was increased. Endpoints included response rate, toxicity, and survival., Methods: Sixty-two patients with unresectable Stage III NSCLC were included. Patients received 2 cycles of induction carboplatin (area under the concentration curve [AUC], 6) and paclitaxel (225 mg/m(2) over 3 hours) every 21 days. On Day 43, concurrent TCRT and weekly (x 6) carboplatin (AUC, 2) and paclitaxel (45 mg/m(2)/3 hours) were initiated. The TCRT dose was escalated from 60 to 74 Gy in 4 cohorts (60, 66, 70, and 74 Gy)., Results: The response rate to induction carboplatin/paclitaxel was 40%. Eight patients (13%) progressed on the induction phase. No dose-limiting toxicity was observed during the escalation of the TCRT dose from 60 to 74 Gy. The major toxicity was esophagitis, however, only 8% developed Grade 3/4 esophagitis using Radiation Therapy Oncology Group criteria. The overall response rate was 52%. Survival rates at 1, 2, 3, and 4 years were 71%, 52%, 40%, and 36%, respectively, with a median survival of 26 months. The 1-, 2-, and 3-year progression free survival probabilities were 47%, 35%, and 29%, respectively., Conclusions: Incorporation of TCRT with sequential and concurrent carboplatin/paclitaxel is feasible, and dose escalation of TCRT to 74 Gy is possible with acceptable toxicity. Overall response and survival rates are encouraging. Both locoregional and distant failure remain problematic in this population of patients., (Copyright 2001 American Cancer Society.)

Background: Tracheobronchial injury is a recognized, yet uncommon, result of blunt trauma to the thorax. Often the diagnosis and treatment are delayed, resulting in attempted surgical repair months or even years after the injury. This report is an extensive review of the literature on tracheobronchial ruptures that examines outcomes and their association with the time from injury to diagnosis., Methods: We reviewed all patients with blunt tracheobronchial injuries published in the literature to determine the anatomic location of the injury, mechanism of the injury, time until diagnosis and treatment, and outcome. Only patients with blunt intrathoracic tracheobronchial traumas were included., Results: We identified 265 patients reported between 1873 and 1996. Motor vehicle accidents were the most frequent mechanism of injury (59%). The overall mortality among reported patients has declined from 36% before 1950 to 9% since 1970. The injury occurred within 2 cm of the carina in 76% of patients, and 43% occurred within the first 2 cm of the right main bronchus. The proximity of the injury to the carina had no detectable effect on mortality. Injuries on the right side were treated sooner but were associated with a higher mortality than left-sided injuries. No association was detected between delay in treatment and successful repair of the injury; ninety percent of patients undergoing treatment more than 1 year after injury were repaired successfully., Conclusions: This review of patients with blunt tracheobronchial injuries represents the largest cohort studied to date. These data suggest an ability to repair tracheobronchial injuries successfully many months after they occur. We are also able to assess the mortality associated with the location and side of injury, examine the time from injury until diagnosis and treatment, and evaluate treatment outcome.

Objective: The rate of complete resection (50%) and the 5-year survival (30%) for non-small cell lung carcinomas of the superior sulcus have not changed for 40 years. Recently, combined modality therapy has improved outcome in other subsets of locally advanced non-small cell lung carcinoma. This trial tested the feasibility of induction chemoradiation and surgical resection in non-small cell lung carcinoma of the superior sulcus with the ultimate aim of improving resectability and survival., Methods: Patients with mediastinoscopy-negative T3-4 N0-1 superior sulcus non-small cell lung carcinoma received 2 cycles of cisplatin and etoposide chemotherapy concurrent with 45 Gy of radiation. Patients with stable or responding disease underwent thoracotomy 3 to 5 weeks later. All patients received 2 more cycles of chemotherapy and were followed up by serial radiographs and scans. Survival was calculated by the Kaplan-Meier method and prognostic factors were assessed for significance by Cox regression analysis., Results: From April 1995 to September 1999, 111 eligible patients (77 men, 34 women) were entered in the study, including 80 (72.1%) with T3 and 31 with T4 tumors. Induction therapy was completed as planned in 102 (92%) patients. There were 3 treatment-related deaths (2.7%). Cytopenia was the main grade 3 to 4 toxicity. Of 95 patients eligible for surgery, 83 underwent thoracotomy, 2 (2.4%) died postoperatively, and 76 (92%) had a complete resection. Fifty-four (65%) thoracotomy specimens showed either a pathologic complete response or minimal microscopic disease. The 2-year survival was 55% for all eligible patients and 70% for patients who had a complete resection. To date, survival is not significantly influenced by patient sex, T status, or pathologic response., Conclusions: (1) This combined modality treatment is feasible in a multi-institutional setting; (2) the pathologic complete response rates were high; and (3) resectability and overall survival were improved compared with historical experience, especially for T4 tumors, which usually have a grim prognosis.

Background: A modified Phase I trial was conducted evaluating the incorporation of 3-dimensional conformal radiation therapy (3DCRT) into a strategy of sequential and concurrent carboplatin/paclitaxel in Stage III, unresectable nonsmall cell lung carcinoma (NSCLC). In addition, dose escalation of thoracic conformal radiation therapy (TCRT) from 60 to 74 gray (Gy) was performed. Endpoints included response rate, toxicity, and survival., Methods: Twenty-nine patients with unresectable Stage III NSCLC were included. Patients received 2 cycles of induction carboplatin (AUC 6) and paclitaxel (225 mg/m(2)/3 hours) every 21 days. On Day 43, concurrent TCRT and weekly (x6) carboplatin (AUC 2) and paclitaxel (45 mg/m(2)/3 hours) was initiated. The TCRT dose was escalated from 60 to 74 Gy in 4 cohorts., Results: The response rate to induction carboplatin/paclitaxel was 52%. Three patients (10%) experienced disease progression during the induction phase. No dose-limiting toxicity was seen during the escalation of the TCRT dose from 60 to 74 Gy. The major toxicity was esophagitis, with 18% of patients developing Radiation Therapy Oncology Group Grade 3 esophagitis. The overall response rate was 70% (1 complete response and 18 partial responses). Survival rates at 1 and 2 years were 69% and 45%, with a median survival of 21 months. The 1-year progression free survival probability was 41% (95% confidence interval, 23-59%)., Conclusions: Incorporation of 3DCRT with sequential and concurrent carboplatin/paclitaxel is feasible, and dose escalation of TCRT to 74 Gy is possible with acceptable toxicity. Overall response and survival rates are encouraging. Accrual is continuing in a Phase II fashion at 74 Gy with sequential and concurrent carboplatin/paclitaxel., (Copyright 2000 American Cancer Society.)

Background: Combined-modality therapy has become standard for many patients with non-small cell lung cancer. Although surgical resection offers the best chance for long-term survival, the limited number of resectable patients and the presence of occult micrometastatic disease has limited the effectiveness of this modality alone., Methods: The authors reviewed several trials involving the use of induction chemotherapy in managing resectable non-small cell lung cancer., Results: Extensive phase II experience in patients with stage III disease has confirmed the feasibility of this approach. Unfortunately, heterogeneous patient populations and treatment regimens limit the ability to draw firm conclusions from these trials alone. While the phase III experience has been limited, long-term follow-up is now available suggesting that induction therapy may have a beneficial impact on survival, especially for those patients who can be sufficiently downstaged. Recent phase II trials have included stage III patients who have traditionally been considered inoperable. Although encouraging, the role of surgery after chemoradiotherapy for this population of patients remains undefined., Conclusions: Results from ongoing randomized trials studying the impact of induction therapy on well-defined patient populations will be necessary before the optimal regimen and patient population can be identified.

Pancoast or superior pulmonary sulcus tumors are uncommon primary bronchogenic carcinomas that produce a characteristic clinical syndrome of upper extremity pain and Horner's syndrome. Treatment of patients with this malignancy has traditionally involved irradiation alone or preoperative irradiation followed by resection. Recent advances in the management of Pancoast tumors include the importance of mediastinoscopy in staging the tumor before treatment begins. A complete resection should be accomplished including a lobectomy whenever possible. The current treatment protocol involves induction chemoradiotherapy followed by surgery.

Carcinoid tumors have been described in almost every organ and may affect virtually every body system. Cardiac involvement manifesting as right-sided valvular disease is characteristic of the carcinoid syndrome; however, direct myocardial involvement is unusual. We present a case of an invasive carcinoid tumor whose primary manifestation was myocardial invasion.

Background: Induction chemoradiotherapy followed by esophagectomy may provide results superior to those of single-modality treatment in patients with esophageal cancer. The purpose of this study was to review our experience with this approach for esophageal cancer., Methods: From 1988 to 1996, 166 consecutive patients with esophageal cancer were evaluated; 66 entered a protocol of chemotherapy (5-fluorouracil, cisplatin) concurrent with radiation (45 Gy) followed by esophagectomy. Fifty-four patients completed the protocol., Results: Toxicity associated with induction chemoradiotherapy was minimal. The actuarial survival at 12, 24, and 36 months was 59%, 42%, and 32%, respectively. The pathologic complete response (pCR) rate was 41%, with 12-, 24-, and 36-month survivals of 77%, 50%, and 45%, whereas non-pCR patients had survivals of 46%, 35%, and 23%. The difference in survival between pCR and non-pCR patients was not significant (p = 0.13), but the difference in recurrence-free survival was significant (p = 0.007)., Conclusions: This well-tolerated protocol resulted in a high pCR. Trimodality treatment for esophageal cancer may provide long-term survival in some patients regardless of their pCR status.

It has been suggested that T3/N0-1/M0 non-small cell lung cancer should be classified as stage IIB rather than IIIA. This is the result of a widespread perception that the survival of patients with T3/N0-1 lung cancers greatly exceeds that of patients with stage IIIA (N2) lung cancers. This perception is based primarily on the survival of T3/N0-1 patients who have chest wall involvement. However, the T3 classification also includes tumors that involve mediastinal structures, the main stem bronchus <2 cm from the carina, and the brachial plexus as seen in Pancoast tumors. Survival for each of these T3 categories is examined in this articles and found to be somewhat different. The available data show that patients with T3/N0-1 tumors involving the chest wall have a good prognosis after resection, whereas patients with central T3/N0-1 tumors (mediastinal or main stem bronchial involvement) have a prognosis similar to that of patients with resected IIIA (N2) tumors. If a new classification of T3/N0-1 tumors as stage IIB is to be adopted, it will be important for future studies to document which type of T3 tumor is being discussed.

Primary carcinomas arising in the apex of the lung (Pancoast tumors) have attracted attention because of the characteristic syndrome that is produced by local extension into the chest wall and the brachial plexus. This article reviews the history of the treatment of this disease, the natural history of untreated patients, and the diagnosis of Pancoast tumors. The published data on results, prognostic factors, and technical aspects of treatment with combined irradiation and operation are examined, as well as those pertaining to treatment with irradiation alone.

Background: Between June 1997 and November 1993, 100 consecutive thymectomies for myasthenia gravis were performed at University of North Carolina Hospitals in Chapel Hill., Methods: A consistent, planned protocol involving preoperative, intraoperative, and postoperative care was followed. All thymectomies were performed through a median sternotomy with removal of all visible thymus and perithymic fat in the anterior mediastinum., Results: There was no perioperative mortality or longterm morbidity. Mean postoperative hospital stay was 6.3 days (range, 3 to 18 days). Ninety-six percent of the patients were extubated the day of the operation, and all patients were extubated within 24 hours. Mean postoperative intensive care unit stay was 1.2 days (range, 1 to 4 days). After a mean follow-up of 65 months (range, 1 to 199 months), 78% of all patients are improved by at least one modified Osserman classification when their current status is compared with their worst preoperative disease severity. In fact, 69% of patients with mild disease preoperatively (class I, II, or III maximal severity) are in pharmacologic remission (asymptomatic without regular medication), whereas 29% of patients with severe disease (class IV or V) are in remission (p = 0.0001)., Conclusions: Our programmatic approach to thymectomy through a sternotomy has shown minimal morbidity and mortality. It is beneficial to myasthenics at both ends of the age and severity spectrum.

Bone destruction as a manifestation of Wegener's granulomatosis has been reported, but these cases were limited to the head and face. We present a case in which a sternal abscess was the initial manifestation of Wegener's granulomatosis. We believe this is the first reported case of bone destruction due to Wegener's occurring in a location other than the head and face.

The transverse thoracosternotomy provides excellent exposure for repair of lesions involving the entire thoracic aorta. This approach has been made more feasible by other recent technical advances, such as retrograde perfusion of the brain during circulatory arrest, allowing single-stage replacement of the ascending and descending aorta and aortic arch. The two cases presented here illustrate the use of these advancements in the treatment of extensive aneurysms of the thoracic aorta.

Patients with cystic fibrosis (CF) are being considered in increasing numbers as candidates for lung transplantation, despite earlier concerns that their nutritional status and the infective nature of their lung disease would contribute to increased morbidity and mortality. We undertook a retrospective analysis of patients with CF referred for consideration of lung transplant to identify factors that helped to select suitable transplant candidates and to identify characteristics that predicted death while on the waiting list. Analysis of 95 referred patients with CF demonstrated a high rate of suitability (78%) by our criteria. The mean weight of listed patients with CF was 77% predicted, and the mean FEV1 was 20% predicted. Sixteen percent of listed patients with CF died awaiting transplant. The FEV1 of these patients was significantly lower than that of patients who survived to transplant. This study implies that patients with CF are being referred for transplant late in the course of their disease. Earlier referral may lead to an increase in the number of patients with CF undergoing successful lung transplantation.

Current United Network for Organ Sharing policy requires listing lung transplant recipients with an acceptable donor weight range, but lung size is a function of height, age, sex, and race. Frequently, lung transplant recipients are underweight, which results in a large discrepancy between donor and recipient weights. We reviewed our experience with size discrepancy between donors (D) and recipients (R) of 49 double-lung transplant (DLTX) procedures since July 1990. Pneumoreduction procedures were performed in 11 recipients of lungs judged to be too large at the time of DLTX (right middle lobectomy, 2; lingulectomy, 2; both, 6; right middle lobectomy and bilateral apical resections, 1). Predicted forced vital capacity (FVC) and total lung capacity (TLC) of donors and recipients were calculated. Donors were larger than recipients in general (D:R height = 1.02; D:R weight = 1.46), and, as a result, recipient-predicted lung volumes were smaller than donor-predicted lung volumes (D:R FVC = 1.1; D:R TLC = 1.1). Recipients undergoing pneumoreduction procedures had a significantly greater size discrepancy between donors and recipients; thus, both the ratio of D:R and the difference between D and R predicted FVC and TLC were significantly greater among recipients who underwent pneumoreduction, compared with nonreduced recipients. For recipients in the pneumoreduction group, predicted FVC and TLC were recalculated, with a proportionate amount subtracted based on the number of pulmonary segments removed. When the "corrected" FVC and TLC of the donors were compared with recipient-predicted FVC and TLC, there was no longer any significant difference between reduced and non-reduced groups, which implies that visual estimate of size mismatch at surgery is an accurate measure of size discrepancy. Post-DLTX spirometry showed identical improvement in FVC in patients who had pneumoreduction and those who did not, and survival at 6 months was identical in both groups. We conclude that pneumoreduction had no adverse effect on survival or post-DLTX spirometry, allowing safe use of larger donors in small recipients. Also, because lung size is more a function of height than weight, this study challenges the United Network for Organ Sharing practice of listing recipients with an acceptable donor weight range.

Patients with cystic fibrosis pose particular challenges for lung transplant surgeons. Earlier reports from North American centers suggested that patients with cystic fibrosis were at greater risk for heart-lung or isolated lung transplantation than other patients with end-stage pulmonary disease. During a 3 1/2 year period, 44 patients with end-stage lung disease resulting from cystic fibrosis underwent double lung transplantation at this institution. During the same interval, 18 patients with cystic fibrosis died while waiting for lung transplantation. The ages of the recipients ranged from 8 to 45 years, and mean forced expiratory volume in 1 second was 21% predicted. Seven patients had Pseudomonas cepacia bacteria before transplantation. Bilateral sequential implantation with omentopexy was used in all patients. There were no operative deaths, although two patients required urgent retransplantation because of graft failure. Cardiopulmonary bypass was necessary in six procedures in five patients and was associated with an increased blood transfusion requirement, longer postoperative ventilation, and longer hospital stay. Actuarial survival was 85% at 1 year and 67% at 2 years. Infection was the most common cause of death within 6 months of transplantation (Pseudomonas cepacia pneumonia was the cause of death in two patients), and bronchiolitis obliterans was the most common cause of death after 6 months. Actuarial freedom from development of clinically significant bronchiolitis obliterans was 59% at 2 years. Results of pulmonary function tests improved substantially in survivors, with forced expiratory volume in 1 second averaging 78% predicted 2 years after transplantation. Double lung transplantation can be accomplished with acceptable morbidity and mortality in patients with cystic fibrosis.

A 3-month-old infant with failure to thrive was found on bronchoscopy to have tracheal obstruction thought to be secondary to innominate artery compression. Subsequent diagnostic evaluation with magnetic resonance imaging revealed superior and posterior extension of the thymus with resultant compression of the innominate artery and trachea within the narrow confines of the thoracic inlet. Resection of the aberrantly positioned and enlarged thymus and aortopexy resulted in relief of tracheal compression.

Kearns-Sayre syndrome is the triad of progressive external ophthalmoplegia, pigmentary retinopathy, and complete AV block. The etiology is unknown, but is thought to be due to a mitochondrial DNA deletion. Reported electrocardiographic abnormalities include first-degree AV block, fascicular blocks, and complete heart block, as well as non-specific S-T segment changes and T wave abnormalities, but has not included sinus node dysfunction. We report a case with episodes of sinus arrest in an asymptomatic patient with Kearns-Sayre syndrome resulting in pauses lasting up to 6 seconds.

In our armamentarium of various thoracic incisions, we have incorporated a vertical skin incision with a muscle-sparing approach to gain access to the thorax. We find this incision gives excellent exposure, preserves function of the chest wall musculature, and leaves a cosmetically superior result.

As lung transplantation has become more successful, the selection criteria have broadened; however, some relative contraindications to lung transplantation are controversial. Some programs consider mechanical ventilation to be a major contraindication to lung transplantation because airway colonization with bacteria may lead to nosocomial infection and respiratory muscle deconditioning may necessitate prolonged postoperative ventilatory support. We report our experience of seven double lung transplant procedures on six patients requiring mechanical ventilation. Five patients with cystic fibrosis required preoperative mechanical ventilation for 7 to 19 days (mean, 10.7 days). One patient with acute lung injury required 115 days of preoperative mechanical ventilatory support. Only the latter patient required prolonged (27 days) postoperative mechanical ventilation because of respiratory muscle weakness; the others were extubated in 1 to 19 days (mean, 7.8 days). No early complications related to bacterial infection were seen. Two patients required temporary hemodialysis for transient kidney failure. Three patients had postoperative neurologic residua; one patient had a transient hemiparesis, and seizures developed in two patients. One patient died 3 months after transplantation from severe central nervous system complications with no evidence of pulmonary problems; and two patients died 17 months after transplantation, one of them receiving a second double lung transplant for obliterative bronchiolitis. Except for the patient who required prolonged preoperative ventilatory support, mechanical ventilation did not appear to play a role in the outcome of these patients. The posttransplantation hospital stay and hospital charges for patients requiring pretransplantation ventilatory support were not significantly different from those for other lung transplant recipients.(ABSTRACT TRUNCATED AT 250 WORDS)

An anomalous course of the left brachiocephalic vein beneath the aortic arch was identified in 7 patients undergoing surgical repair of congenital cardiac malformations. Six of these patients had the morphologic features of tetralogy of Fallot including severe obstruction to the right ventricular outflow tract and a right aortic arch. A review of the literature reveals this to be an uncommon anomaly. When it is present, however, it is frequently associated with a ventricular septal defect, obstruction of the right ventricular outflow, and aortic arch anomalies. This anomaly can be documented by echocardiography, at cardiac catheterization, or intraoperatively. The presence of a subaortic left brachiocephalic vein may have implications for the conduct of surgical procedures, especially in the setting of tetralogy of Fallot.

We present a method of pacemaker implantation in neonates using a subxyphoid epicardial lead and subrectus placement of the pulse generator. This method is simple and safe and carries minimal morbidity.

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)

Routine computed tomographic scan is advocated as the best noninvasive method of evaluating mediastinal nodes for cancer spread. Positive studies should be confirmed histologically. Large size, central location, unfavorable cell type, poor cellular differentiation of the primary cancer, and weight loss also correlate with increased likelihood of mediastinal involvement.

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.

An in vivo canine model was used to assess the ability of an oxygen free radical scavenger to decrease reperfusion injury in lung transplantation. In 12 dogs, the left lungs were transplanted after they had been preserved for 24 hours at 4 degrees C after pulmonary artery flushing with modified Eurocollins solution. In 6 dogs, dimethylthiourea, a potent oxygen free radical scavenger, was added to the flush solution and was also given to the recipients just before reperfusion. In all animals, the contralateral pulmonary artery and bronchus were ligated and lung function was assessed for 12 hours or until death. Three dogs died prematurely in the control group, whereas only 1 dog died prematurely in the dimethylthiourea group. This resulted in a statistically significant difference in the average length of survival (p less than 0.05). Pulmonary artery and right atrial pressures were significantly lower in the dimethylthiourea group during the first 6 hours (p less than 0.05). Treatment with dimethylthiourea resulted in a significantly higher arterial oxygen tension at 4 hours, and intrapulmonary shunt tended to be lower. Thus, it would appear that dimethylthiourea has a protective effect on lungs preserved for 24 hours before transplantation in dogs.