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Biomedical subjects

R D Dowling

Publications and source records attributed to R D Dowling.

At least 37 records · Page 2Linked to original sources
PubMed1993

Postoperative pain-related morbidity: video-assisted thoracic surgery versus thoracotomy.

One hundred thirty-eight consecutive, nonrandomized patients, with equivalent demographic and preoperative physiologic parameters, underwent either a video-assisted thoracic surgical (VATS) approach (n = 81) or a limited lateral thoracotomy (LLT) approach (n = 57) to accomplish pulmonary resection for peripheral lung lesions (< or = 3 cm in diameter). Wedge resection was done in 74 VATS patients and 19 LLT patients. Seven patients underwent VATS lobectomy and 38 patients had lobectomy performed through an LLT. Pain was quantitated by postoperative narcotic requirements, the need for intercostal/epidural analgesia, and patient perception of pain index scoring. Shoulder and pulmonary function (forced expiratory volume in 1 second) were measured preoperatively, 3 days postoperatively, and at 3 weeks of follow-up. Patients undergoing VATS experienced significantly less postoperative pain. No patients undergoing VATS required intercostal block/epidural analgesia; 31 LLT patients (54%) required this treatment for breakthrough pain (p = 0.001). Narcotic requirements were less (p = 0.05) among VATS patients, which correlated with lower perception of pain index after operation for VATS patients. Shoulder girdle strength was equally impaired at day 3, but function was more improved in VATS patients at 3 weeks (p = 0.01). Patients undergoing wedge resection alone by LLT had greater impairment in early (day 3) pulmonary function (forced expiratory volume in 1 second) (p = 0.002); this difference from VATS was not sustained at 3 weeks. Video-assisted thoracic surgery is associated with reduced pain, shoulder dysfunction, and early pulmonary impairment compared with LLT for select patients requiring pulmonary resection.

Humans↗
PubMed1993

Strategic planning for video-assisted thoracic surgery.

As with any operative procedure, careful preoperative and intraoperative planning are vital to achieving a safe and effective video-assisted thoracic surgical intervention. We outline some of our basic strategies for enhancing the success of this approach in the management of thoracic surgical problems.

Humans↗
PubMed1993

VATS wedge resection of the lung using the neodymium:yttrium-aluminum garnet laser.

Many thoracic surgical procedures previously performed using open thoracotomy techniques can now be accomplished using video-assisted thoracic surgical approaches. This has primarily resulted from improvements in both the video and surgical instrumentation and the development of an effective endoscopic surgical stapling device. Laser technology that has been adapted for use in endoscopic surgery has been extended to video-assisted thoracic surgical applications for the resection of pulmonary nodules difficult to manage with the endoscopic stapler alone. We present our experience with the neodymium:yttrium-aluminum garnet laser as either a primary resective tool or as an adjunct to the endoscopic stapler in 67 consecutive patients who underwent video-assisted thoracic surgical wedge resection of the lung.

Female↗
PubMed1993

Video-assisted thoracoscopic resection of pulmonary metastases.

Pulmonary lesions in patients with malignancy often require resection to provide prognostic information and to dictate further therapy. Metastasectomy may also favorably influence survival in select patients with favorable tumor histologies. Seventy-two patients with a history of malignancy and new lung lesions identified by high resolution computed tomography underwent thoracoscopic resection. The operative approach was with standard techniques using two or three trocar sites. Preoperative needle localization was used in 13 patients with small lesions that were not immediately subpleural. All target lesions were identified at thoracoscopy. Exploratory thoracoscopy was followed by parenchymal sparing wedge resection with the endoscopic stapler, the neodymium:yttrium-aluminum garnet laser, or both. Histologic analysis revealed metastatic disease in 63 patients and benign disease in 9 patients. The mean diameter of the lesions was 1.6 cm. The mean duration of chest tube drainage and postoperative hospital stay were 2.1 and 4.1 days, respectively. Thoracoscopic resection appears to be a valid approach for diagnostic resection of presumed metastases. The role of thoracoscopy in therapeutic metastasectomy remains to be defined.

Chest Tubes↗
PubMed1993

Septal myectomy with a carbon dioxide laser for hypertrophic cardiomyopathy.

Septal myectomy with a noncontact carbon dioxide laser for hypertrophic cardiomyopathy is described. This technique results in improved visualization of the septum as the laser beam is held outside the heart and the resecting laser beam can always be clearly seen. We believe this approach provides an improved method of septal myectomy in hypertrophic cardiomyopathy.

Aged↗
PubMed1993

Clinical cardiopulmonary bypass without systemic anticoagulation.

Heparin-coated perfusion systems have been used to perform cardiopulmonary bypass with decreased systemic heparin dosages. We report the case of a 60-year-old man with end-stage liver disease and severe aortic stenosis who underwent an aortic valve replacement without systemic anticoagulation, employing a heparin-coated perfusion system. In patients with a contraindication to systemic anticoagulation, cardiopulmonary bypass with a heparin-coated system without systemic anticoagulation may be a viable alternative.

Aortic Valve↗
PubMed1993

Comparison of open versus thoracoscopic lung biopsy for diffuse infiltrative pulmonary disease.

BACKGROUND: Patients with diffuse pulmonary infiltrates often require biopsy for a diagnosis. Standard operative therapy, open wedge resection via thoracotomy, is associated with known morbidity. We hypothesized that closed thoracoscopic wedge resection may result in reduced morbidity and decreased duration of hospital stay. This retrospective study compares open resection with thoracoscopic wedge resection in patients with diffuse pulmonary infiltrates. METHODS: Seventy-five patients with diffuse pulmonary infiltrates underwent diagnostic lung biopsy. Patients requiring mechanical ventilation and high levels of pressure support before biopsy were excluded from the study. Between March 1987 and September 1991, a total of 28 patients underwent open wedge resection via lateral thoracotomy. Since April 1991, a total of 47 patients underwent thoracoscopic resection. RESULTS: There was no difference between the groups in age, sex, presence of immunosuppression, or final pathologic diagnosis. Adequate tissue was obtained for pathologic diagnosis in all patients of both groups. All surgeons believed that thoracoscopic biopsy provided better visualization of the entire lung than did a limited thoracotomy. Mean operative time was 69 minutes for open biopsies and 93 minutes for thoracoscopic biopsies [p = 0.038]. Mean duration of chest tube drainage was not significantly different between the two groups. Duration of hospital stay was significantly less for thoracoscopic biopsy (4.9 days) than for open biopsy (12.2 days) (p = 0.018). Fourteen of 28 open biopsies resulted in complications compared with 9 of 47 closed biopsies (p = 0.009). There were 6 deaths among patients having open biopsies and 3 deaths among those having closed biopsies (p = not significant). CONCLUSION: A significant decrease in hospital stay was noted with thoracoscopic biopsy when compared with lung biopsy via the standard open approaches. Thoracoscopy provided excellent visualization and allowed for wedge resection that provided adequate tissue for diagnosis in patients with diffuse pulmonary interstitial disease.

Adult↗
PubMed1993

Thoracoscopic mediastinal lymph node sampling: useful for mediastinal lymph node stations inaccessible by cervical mediastinoscopy.

Cervical mediastinoscopy is useful for the diagnosis of paratracheal lymph node metastasis from bronchogenic carcinoma. Access to adenopathy in the aorticopulmonary window, anterior mediastinal, periazygos, and subcarinal lymph nodes is difficult with this technique. Operative visibility in these locations through anterior mediastinotomy, the Chamberlain procedure, is limited. We have used thoracoscopic mediastinal exploration in 40 patients with computed tomographic scan evidence of enlarged aorticopulmonary window (n = 30) or enlarged right periazygos or subcarinal lymph nodes (n = 10). This procedure was used primarily as an adjunct to cervical mediastinoscopy in the staging of bronchogenic carcinoma. Adjunctive thoracoscopic nodal sampling was 100% sensitive and 100% specific in diagnosing the mediastinal adenopathy. It did not significantly delay thoracotomy in cases of benign adenopathy. Visibility of the ipsilateral pleural space and mediastinum was excellent. Thoracoscopic exploration with mediastinal nodal sampling is a valuable diagnostic adjunct for assessment of adenopathy inaccessible to cervical mediastinoscopy and can overcome many of the limitations of anterior mediastinotomy.

Adult↗
PubMed1992

Thoracoscopic neodymium: yttrium aluminum garnet laser resection of a pulmonary metastasis.

BACKGROUND: Patients with a history of malignant disease and new pulmonary lesions often are considered for resection to establish a diagnosis and, with certain histologic subtypes, to improve survival. Standard operative therapy consists of thoracotomy and wedge resection of the lesion. Early and late postoperative morbidity is substantial and related primarily to the thoracotomy incision. METHODS: Advances in endoscopic surgical techniques and laser technology allowed for successful thoracoscopic resection of an isolated pulmonary metastasis in a 59-year-old man with a history of a T3N0M0 renal cell carcinoma. RESULTS: The margins of the specimen were free of tumor. The postoperative course was uncomplicated, and the patient was discharged on the fourth postoperative day. The morbidity associated with a standard thoracotomy was avoided, and an adequate resection was obtained. CONCLUSION: Continued success with thoracoscopic resection may have a significant impact on the management of selected patients with a history of malignant disease and new pulmonary lesions.

Aluminum↗
PubMed1992

Thoracoscopic resection of 85 pulmonary lesions.

Advances in endoscopic surgical equipment and laser technology have expanded the role of thoracoscopy to include thoracoscopic pulmonary resection. Eighty-five thoracoscopic pulmonary resections were performed on 61 consecutive patients with small lesions (less than 3 cm) in the outer third of the lung. Patients with preoperative histologic evidence of bronchogenic carcinoma were excluded unless there was impairment of cardiopulmonary function, advanced age, or concomitant extrathoracic malignancy. These thoracoscopic pulmonary resections were accomplished with the neodymium:yttrium-aluminum garnet laser (31), endoscopic stapler (29), or both (25). The mean diameter of the lesions was 1.3 cm (range, 0.4 to 2.7 cm). There has been one late death (38th postoperative day) unrelated to the operation. Morbidity consisted of postoperative atelectasis (2), pneumonia (2), bleeding requiring transfusion (1), and bronchopleural fistula of greater than 7 days duration (3). There were no wound problems. The mean period of chest tube drainage was 3.3 +/- 3.0 days. Mean postoperative stay was 5.7 +/- 4.9 days. The pathologic diagnosis was benign disease in 28 patients (interstitial fibrosis/pneumonitis, 15; radiation fibrosis, 1; sclerosing hemangioma, 1; rheumatoid nodules, 1; granuloma, 2; nocardia, 1; infarct, 1; hamartoma, 4; scar, 1; cytomegalovirus pneumonia, 1), metastatic malignancy in 20 patients, and bronchogenic carcinoma in 13 patients. Five patients found at thoracoscopic pulmonary resection to have bronchogenic cancer had adequate pulmonary function and therefore underwent formal segmentectomy (3) or lobectomy (2). Thoracoscopic pulmonary resection was the only operation performed on patients with benign disease, patients with metastatic lesions, and selected patients with limited stage bronchogenic carcinoma at increased risk for thoracotomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1992

Video-assisted thoracic surgery: basic technical concepts and intercostal approach strategies.

Video-assisted thoracic surgery is emerging as a viable approach to a number of intrathoracic disorders. Technical difficulties related to improper instrument selection and suboptimal intercostal operative access can reduce the utility of, and the enthusiasm for, the video-assisted thoracic surgical approach. This report describes the intercostal access strategy and the instrument positioning that we now prescribe for many video-assisted thoracic surgical procedures. These approaches have become refined during the course of our experience with 467 patients undergoing video-assisted thoracic operations over the last 18 months.

Endoscopes↗
PubMed1992

Thoracoscopic resection of an anterior mediastinal tumor.

The therapeutic role of thoracoscopy has expanded with advances in endoscopic surgical instrumentation and laser technology. We report a complete thoracoscopic resection of an encapsulated (stage I) thymoma with lymphocytic predominance in an elderly woman without myasthenia gravis. The patient had an uncomplicated postoperative course and was discharged on the third postoperative day. Median sternotomy with its attendant morbidity was avoided. Thoracoscopic resection of thymic neoplasms may be a useful approach in carefully selected patients.

Aged↗
PubMed1992

Improved immunosuppression with aerosolized cyclosporine in experimental pulmonary transplantation.

Rejection remains a major obstacle to long-term success of pulmonary transplantation. Direct delivery of cyclosporine to lung allografts may produce better control of rejection by generating high intragraft concentrations of drug with decreased systemic delivery and toxicity. The efficacy of inhaled cyclosporine in preventing allograft rejection was compared with systemic delivery by intramuscular injections in a rat model of lung transplantation (Brown-Norway to Lewis). Group 1 animals were given no immunosuppression. Group 2 received a single i.m. injection of 25 mg/kg CsA on the day of operation while group 3 received daily doses on postoperative days 0-3. Groups 4-7 received aerosolized CsA daily for seven days. The aerosol generator produced an airborne concentration of CsA of 180 mg/m3 with a mean particle size of 0.7 mu and estimated pulmonary depositions of CsA of 0.98-3.6 mg/kg/day. Animals were killed on POD 7, and the transplanted lungs graded histologically in a blinded fashion. All control animals showed destructive grade 4 changes by POD 7. Animals receiving high-dose aerosolized CsA (groups 6 and 7) showed minimal changes with a mean rejection grade of 1.3. A single i.m. dose of CsA (group 2) failed to prevent rejection; the mean grade was 2.2. Animals given four i.m. doses of CsA had a mean grade of 1.8. Aerosolized CsA provided significantly better control of rejection than did systemic CsA (groups 6 and 7 vs. groups 2 and 3; P less than 0.0002 and less than 0.0054, respectively). Local delivery of CsA by aerosol inhalation is effective in limiting acute rejection of the rat lung allograft.

Aerosols↗
PubMed1992

Thoracoscopic resection of a posterior mediastinal neurogenic tumor.

Advances in endoscopic instrumentation and a growing enthusiasm for minimally invasive surgical techniques have sparked renewed interest in therapeutic thoracoscopy. We report the successful thoracoscopic resection of a posterior mediastinal nerve sheath tumor. A 35-year-old asymptomatic woman was found to have a posterior mediastinal mass on chest roentgenogram. Computed tomography and magnetic resonance imaging confirmed the presence of the lesion and showed no evidence of intraspinal extension. Exploratory thoracoscopy revealed a localized lesion without intraspinal extension. Thoracoscopic resection of the lesion was then performed. The patient's postoperative course was uncomplicated and she was discharged on the fifth postoperative day. The therapeutic potential of thoracoscopy continues to be realized as experience with the technique grows.

Adult↗
PubMed1992

Thoracoscopic resection of pulmonary metastases.

OBJECTIVE: To describe the use of thoracoscopic techniques to achieve parenchymal sparing wedge resection of peripheral lung lesions in patients with a history of malignancy, and to describe the morbidity, mortality, and hospital course associated with this approach. DESIGN: Case series. SETTING: University hospital. PARTICIPANTS: Patients with a history of malignancy and lesions on computerized tomography in the outer one third of the lung parenchyma. MAIN OUTCOME MEASUREMENTS: Histologic analysis of resected lung lesions, operative findings, operative time, duration of chest tube drainage and hospital stay, operative morbidity, and mortality. RESULTS: Twenty-one thoracoscopic resections of pulmonary parenchymal lesions were performed on 15 patients. All peripheral lesions identified by computerized tomography were found at thoracoscopy and successfully resected with the Nd:YAG laser (n = 7), an endoscopic stapler (n = 10), or both (n = 4). The mean diameter of the lesions was 0.8 cm (range 0.2 to 1.5 cm). Histologic analysis revealed metastatic disease in 13 patients and benign disease in 2 patients. All resection margins were free of tumor. The mean duration of chest tube drainage and postoperative hospital stay were 1.8 +/- 0.1 and 3.3 +/- 0.1 days, respectively. Mean operative time was 111 min (range 45 to 155 min). One patient who underwent a right thoracoscopic resection developed a transient left vocal cord paresis. There were no other complications and no deaths. CONCLUSION: Thoracoscopy was successful in identifying peripheral lung lesions and allowed for parenchymal sparing resection identical in extent to that performed with open approaches. For select patients with peripheral lung nodules felt to be metastases, thoracoscopic resection may result in reduced morbidity, cost, hospital stay and allow for more rapid institution of therapy for the primary disease.

Adult↗
PubMed1992

Thoracoscopic Nd:YAG laser resection of a solitary pulmonary nodule.

Advances in endoscopic surgical techniques and laser technology have expanded the role of thoracoscopy. We report a thoracoscopic resection of a benign pulmonary lesion. A 44-year-old man underwent a successful Nd:YAG laser-assisted thoracoscopic resection of a peripheral lung hamartoma. The patient's postoperative course was uncomplicated. Thoracotomy with its attendant morbidity was avoided. Continued success with thoracoscopic resection will have a significant impact on the management of select patients with peripheral, solitary pulmonary nodules.

Adult↗
PubMed1992

Donor-transmitted pneumonia in experimental lung allografts. Successful prevention with donor antibiotic therapy.

Bacterial pneumonia is the most common cause of early morbidity and mortality (less than 2 weeks) after heart-lung transplantation. The majority (76%) of cultures taken from human donor tracheas at the time of explant grew bacteria. The abnormal immune response of the lung allograft and the common finding of bacterial contamination of lung donors led us to hypothesize that clinically silent bacterial contamination of the donor lung progresses to pneumonia in the recipient and that antibiotic treatment of donors will prevent the development of pneumonia in the recipient. Inocula of Streptococcus pneumoniae were instilled into the left middle lobe of normal and donor dogs to identify the number of bacteria that would result in pneumonia in a normal animal and the amount that, when given to a donor, would result in pneumonia in the recipient. Initial studies established that inocula of 10(4) colony-forming units of S. pneumoniae did not result in pneumonia in normal or immunosuppressed animals. When 10(4) colony-forming units or as few as 10(2) were instilled into the left middle lobe of donors 24 hours before explantation and use of the lung for transplantation, severe acute bronchopneumonia developed in all 18 recipients. Treatment of donors with aerosol and intravenous antibiotics, but not with either alone, prevented pneumonia in the recipients. We conclude that bacterial contamination of the donor lung leads to pneumonia in recipients. Intravenous and aerosol antibiotic treatment of donors with bacterial contamination prevents pneumonia in canine lung recipients. Treatment of human donors with this antibiotic regimen may decrease the prevalence of early bacterial pneumonia.

Administration, Inhalation↗