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Biomedical subjects

Richard I Whyte

Publications and source records attributed to Richard I Whyte.

11 recordsLinked to original sources

Are heart-lung transplant recipients protected from developing bronchiolitis obliterans syndrome?

BACKGROUND: Heart-lung transplant recipients, when compared with heart transplant recipients, are relatively spared from allograft coronary artery disease. This study was undertaken to investigate whether heart-lung transplant recipients are also spared from experiencing bronchiolitis obliterans syndrome (BOS) when compared with double-lung transplant recipients. In addition, the risk factors for developing BOS after lung transplantation were analyzed. METHODS: Heart-lung and bilateral sequential double-lung transplant recipients were reviewed retrospectively from 1990 to 2000 using the Stanford Transplant Database. The heart-lung transplant group consisted of 77 heart-lung transplant recipients and the double-lung transplant group consisted of 51 double-lung transplant recipients. The rates of BOS, survival, acute rejection, and cytomegalovirus infection at 1, 3, and 5 years were measured. RESULTS: There were no significant differences in patient demographics between the two groups. Rates of survival and acute rejection were similar in the two transplant groups. The incidence of cytomegalovirus infection was significantly higher in heart-lung transplant recipients. Freedom from BOS was similar in the two transplant groups. Risk factors for the development of BOS in the heart-lung and double-lung transplant recipients included male donor, younger recipient age, a diagnosis other than cystic fibrosis, nonuse of cardiopulmonary bypass, and the use of OKT3 induction therapy. CONCLUSIONS: Heart-lung transplant recipients exhibit BOS at a rate similar to double-lung transplant recipients. The immunoprotective effect the lung allograft presumably provides the heart is not reciprocated by the heart in preventing the development of BOS.

Acute Disease↗

Lung transplantation: a decade of experience.

BACKGROUND: Over the past 3 decades, the field of lung transplantation has been refined. However, many barriers exist that limit long-term success. The purpose of this study was to review a single institution's long-term experience with single and double lung transplantation and to assess the effect of different immunosuppressive therapies on outcomes. METHODS: Lung transplant recipients, both single and double, were reviewed, retrospectively. Patients were divided into five groups: group I, all lung transplants (n = 127); group II, single lung transplants (n = 73); group III, double lung transplants (n = 54); group IV, OKT3 induction therapy recipients (n = 27); and group V, RATG induction therapy recipients (n = 100). Rates of survival, rejection, bronchiolitis obliterans syndrome (BOS) and infection were analyzed at 1, 3, and 5 years. RESULTS: There were no significant differences in survival, acute rejection rate, freedom from BOS, nor infection between single and double lung transplant recipients. Induction therapy with RATG (group V) was associated with significantly improved survival and freedom from acute rejection, BOS, and infection when compared to OKT3 induction therapy (group IV). CONCLUSIONS: An earlier impression that RATG is superior to OKT3 induction therapy has borne true in terms of overall survival and incidence of BOS, acute rejection and infection rates. Lung transplantation, using RATG induction therapy, remains an important modality for end-stage pulmonary disease.

Adult↗

Boerhaave's syndrome: diagnosis and treatment.

Boerhaave's syndrome, or postemetic rupture of the esophagus,represents one of several etiologies of esophageal perforation. Early diagnosis, which requires both a high index of suspicion and contrast esophagography, is essential for optimal outcome. Primary repair is often possible, although other techniques, such as esophageal exclusion or diversion, may be appropriate in certain circumstances.

Esophageal Perforation↗

Preoperative patient education in thoracic surgery.

Preoperative patient teaching may take many forms and is offered to patients across many venues and formats. The goal of patient teaching is to improve patients' understanding of their disease process and the operation that they are about to experience with the goal of enlisting their active participation in the healing process. The additional goal of obtaining informed consent is not only codified in law, but also has become an ingrained component to the current physician-patient relationship. The preoperative teaching process is best approached as a team effort, and multiple modalities often must be used so that the patient becomes a knowledgeable and willing member of the team.

Humans↗

Stereotactic radiosurgery for lung tumors: preliminary report of a phase I trial.

BACKGROUND: Stereotactic radiosurgery is well established for the treatment of intracranial neoplasms but its use for lung tumors is novel. METHODS: Twenty-three patients with biopsy-proven lung tumors were recruited into a two-institution, dose-escalation, phase I clinical trial using a frameless stereotactic radiosurgery system (CyberKnife). Fifteen patients had primary lung tumors and 8 had metastatic tumors. The age range was 23 to 87 years (mean, 63 years). After undergoing computed tomography-guided percutaneous placement of two to four small metal fiducials directly into the tumor, patients received 1,500 cGY of radiation in a single fraction using a linear accelerator mounted on a computer-controlled robotic arm. Safety, feasibility, and efficacy were studied. RESULTS: Nine patients were treated with a breath-holding technique, and 14 with a respiratory-gating, automated, robotic technique. Tumor size ranged from 1 to 5 cm in maximal diameter. There were four complications related to fiducial placement: three pneumothoraces requiring chest tube insertion and one emphysema exacerbation. There were no grade 3 to 5 radiation-related complications. Follow-up ranged from 1 to 26 months (mean, 7.0 months). Radiographic response was scored as complete in 2 patients, partial in 15, stable in 4, and progressive in 2. Four patients died of non-treatment-related causes at 1, 5, 9, and 11 months after radiation. CONCLUSIONS: Single-fraction stereotactic radiosurgery is safe and feasible for the treatment of selected lung tumors. Additional studies are planned to investigate the optimal radiation dose, best motion-suppression technique, and overall treatment efficacy.

Adult↗

Absent secretion to vasoactive intestinal peptide in cystic fibrosis airway glands.

We are testing the hypothesis that the malfunctioning of airway gland serous cells is a component of cystic fibrosis (CF) airway disease. CF is caused by mutations that disrupt CF transmembrane conductance regulator, an anion channel essential for proper fluid secretion in some epithelia. Submucosal glands supply most of the mucus in upper airways, and gland serous cells are the primary site of CF transmembrane conductance regulator expression in airways. We have discovered a major defect in CF glands by in situ optical monitoring of secretions from single human airway glands. CF glands did not secrete to agents that elevated [cAMP](i) (0 responses/450 glands, 8 subjects), whereas glands were responsive in all donor tracheas (605/827 glands, 15 subjects) and in bronchi from subjects who were transplanted because of other lung diseases (148/166 glands, n = 10). CF glands secreted to cholinergic stimulation, and serous cells were abundant in glands from all CF subjects. The complete absence of secretion to agents that elevate [cAMP](i) suggests that altered secretion of gland mucus could contribute to CF lung disease.

Adult↗

Regulatory role of IL-10 in experimental obliterative bronchiolitis in rats.

Obliterative bronchiolitis (OB) affects over half of all chronic human survivors following lung or heart-lung transplantation. Respiratory epithelial cell injury, peribronchial inflammation, and proliferation of fibrovascular connective tissue causing airway occlusion characterize this lesion. Using a rat model of experimental OB, tracheas and mainstem bronchi from Brown-Norway or Lewis (LEW) rats were transplanted subcutaneously into LEW recipients. At 7 days, airway lumens of allografts showed minimal luminal obstruction but significant respiratory epithelial loss. By 14 days, allografts demonstrated marked peribronchial inflammation, nearly complete loss of respiratory epithelium, and extensive intraluminal proliferation of fibrovascular connective tissue, with a mean 58% reduction in airway cross-sectional diameter. However, isografts showed only limited peribronchial inflammation and no loss of airway lumen. When recipients of allotransplants were treated with anti-IL-10, OB developed more rapidly. As early as 7 days, there was marked histologic evidence of OB and a 43% reduction in mean cross-sectional area. Allograft animals that received 5 microg/day of recombinant IL-10 as a constant infusion on day 14 showed almost complete preservation of respiratory epithelium and only mild peribronchial inflammation with only a 15% reduction in airway cross-sectional area. These findings suggest that endogenous IL-10 plays a regulatory role in the development of experimental OB.

Animals↗

Lung and heart-lung transplantation in patients with end-stage cystic fibrosis: the Stanford experience.

BACKGROUND: Bilateral lung (BLTx) and heart-lung transplantation have gained wide acceptance as treatment of end-stage lung disease from cystic fibrosis. We reviewed our 13-year experience with thoracic transplantation for cystic fibrosis with an operative approach that favors use of cardiopulmonary bypass for BLTx. METHODS: Sixty-four patients with cystic fibrosis underwent heart-lung transplantation (n = 22, 34.4%) or BLTx (n = 42, 65.6%) between 1988 and 2000. Mean age and weight at transplantation were 29 +/- 8 years and 51 +/- 11 kg, respectively. Mean follow-up for survivors was 4.4 +/- 3.6 years. Immunosuppression regimen included cyclosporine, tapered corticosteroids, azathioprine, and induction therapy with OKT3 (murine monoclonal antibodies) or rabbit antithymocyte globulin. Cardiopulmonary bypass was used in all but 5 patients (7.8%). However, in 8 (19%) of the 42 patients having BLTx, only the grafting of the second lung was performed with cardiopulmonary bypass. RESULTS: The operative mortality rate was 1.6%. The actuarial survival rates at 1 year, 3 years, 5 years and 10 years were 93.2%, 77.7%, 61.8%, and 48.1%, respectively, with no significant difference between BLTx and heart-lung transplantation. The major hospital complications were pneumonia (n = 11, 17.2%) and bleeding (n = 8, 12.5%). Clinically significant reperfusion injury was observed in 6 patients, 3 of whom required reintubation. Freedom from acute lung rejection beyond 1 year was 47.7%. One patient underwent late retransplantation, and 4 required bronchial stenting. Obliterative bronchiolitis accounted for eight (50.0%) of 16 late deaths. CONCLUSIONS: Though postoperative bleeding and pneumonia are still of concern, satisfactory early and intermediate-term results can be expected in patients undergoing BLTx or heart-lung transplantation for cystic fibrosis. Cardiopulmonary bypass can be used for BLTx with no adverse impact on intermediate and long-term outcomes.

Adult↗

Role of video-assisted thoracoscopic surgery and classic thoracotomy in lung cancer management.

Lung cancer is the leading cause of cancer-related death worldwide. For patients diagnosed with early-stage lung cancer, complete surgical resection remains the best hope for cure. Limited resections are avoided when possible because of higher recurrence rates and potentially worse long-term survival. Traditionally, a posterolateral thoracotomy has been used to perform anatomic lung resections and mediastinal lymph node dissection for complete staging. More recently, the use of video-assisted thoracoscopic surgery has been introduced for the treatment of stage I lung cancers. Although thought minimally invasive and thus perceived as resulting in less postoperative pain and faster recovery, its acceptance has varied worldwide. Questions about training, cost containment, and oncologic principles prevail. In essence, the absolute indications and limitations of video-assisted thoracoscopic surgery for patients with lung cancer have yet to be defined.

Humans↗