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Biomedical subjects

G A Patterson

Publications and source records attributed to G A Patterson.

At least 235 records · Page 13Linked to original sources
PubMed1989

Use of silicone stents in the management of airway problems.

We report the use of a silicone rubber T tube for the management of complex airway problems in 47 patients during the past 15 years. The tube has been used for palliation in 11 patients with malignant obstruction of the airway, and as the sole treatment or as an adjunct to operation in 36 other patients. Based on the satisfactory results with the use of these tubes, we have utilized silicone stents in the bronchus and bifurcation prostheses at the carina. In the past, we have inserted the T tubes through a tracheostomy stoma. More recently, we have used a technique for endoscopic placement of the T tubes in which the horizontal limb is pulled out through the tracheostomy stoma. This technique facilitates introduction of the tube and maintains the airway during insertion. The use of silicone stents provides an important tool in the management of complicated airway problems, and we anticipate their increased use in the future.

Bronchi↗
PubMed1989

Single-lung transplantation: imaging features.

The imaging studies obtained after single-lung transplantation in 14 patients were reviewed. The reimplantation response occurred in 13 patients and was an early, transient process, which varied in its manifestations from a subtle perihilar haze to dense consolidation with air bronchograms. Nine episodes of acute rejection, an imprecise clinical diagnosis, occurred in eight of the patients. The associated chest radiographic changes were variable and included basal or diffuse reticular interstitial disease in three cases and basal and/or perihilar consolidation in three cases; no change was detected in three cases. On four occasions, the radiographic changes resolved within 24 hours of intravenous corticosteroid administration. The radiographic findings associated with the reimplantation response and rejection were nonspecific and could have been mistaken for those of fluid overload, atelectasis, mucous plugging, and pneumonia. Bronchial dehiscence was well demonstrated by the finding at computed tomography of extraluminal air adjacent to the bronchial anastomosis. One patient developed multiple pulmonary nodules due to cyclosporine-induced lymphoma.

Acute Disease↗
PubMed1989

Double-lung transplant for advanced chronic obstructive lung disease.

We have achieved repeated success with unilateral lung transplantation for pulmonary fibrosis and have developed an en bloc, double-lung transplant procedure for patients with advanced lung disease of an obstructive or infective nature. Six such procedures have now been performed for end-stage emphysema, and all recipients are alive and well 5 to 15 months later. A seventh transplant for primary pulmonary hypertension was unsuccessful. All recipients were judged to have a life expectancy of 12 to 18 months on the basis of the degree of disability and the documented rate of disease progression. We feel the double-lung procedure is more appropriate than the combined heart-lung transplant for patients requiring replacement of both lungs when right heart function is adequate or deemed recoverable. With this procedure, the recipient is able to retain his or her own heart, avoiding the liabilities associated with cardiac transplantation. Furthermore, the donor heart is available for a separate recipient, and this sharing of the heart and lungs greatly increases the supply of transplantable lungs for patients with end-stage lung disease. Ischemia of the donor airway has been a source of complication, including the one death to date, but this appears to be a surmountable problem.

Adult↗
PubMed1989

Chest radiographic findings after bilateral lung transplantation.

We reviewed the postoperative chest radiographic and CT findings in the first 13 patients who underwent bilateral lung transplantation at our institution. Portable chest radiography was performed daily for about 10 days, after which upright posteroanterior studies were performed daily for about 10 days, and then as clinically required. CT was performed when a complication was suspected. The reimplantation response (noncardiogenic pulmonary edema due to ischemia, trauma, denervation, and lymphatic interruption) occurred in 12 patients and usually consisted of bilateral perihilar and basal consolidation. Twelve episodes of acute rejection, an imprecise clinical diagnosis, occurred in 10 patients. Radiographic changes consisted of bibasal (n = 2), right mid and lower (n = 2), or left basal consolidation (n = 1); there were no changes in seven episodes. Radiographic resolution occurred in four cases after administration of IV steroids. The radiographic findings associated with the reimplantation response and rejection were nonspecific and were mimicked by fluid overload and infection. Bronchial dehiscence and/or stricture formation occurred in seven patients; generally chest radiography was inaccurate and CT was very accurate in the assessment of these complications. Chest radiography was helpful but not definitive in sorting out the problems occurring in the postoperative period after bilateral lung transplantation. CT was excellent for use in demonstrating airway problems.

Adolescent↗
PubMed1989

A method for safe twelve-hour pulmonary preservation.

The clinical application of lung transplantation is severely limited by the shortage of suitable donor organs. Current techniques of lung preservation allow a maximum of 4 to 6 hours of safe ischemic time. The function of canine left lung allografts stored for 12 hours after being cooled by pulmonary artery flush was studied. Two types of flush solution were used: group I; Euro-Collins solution; group II, low-potassium-dextran solution. Lung function was studied immediately and 3 days after transplantation. This protocol enables study of acute preservation-related lung injury and the delayed manifestations of ischemic and reperfusion injury after a 3-day period of recovery. Inflatable cuffs were placed around each pulmonary artery at operation and were attached to subcutaneous injection ports. Temporarily occluding either pulmonary artery allowed independent study of the native or transplanted lung. Using this model, we were able to demonstrate reliable and reproducible preservation of lungs for 12 hours. The low-potassium-dextran solution provided significantly better immediate function of the preserved lung than the Euro-Collins solution: arterial oxygen tension 509 +/- 15 mm Hg versus 111 +/- 16 mm Hg (p less than 0.0001). Function on the third day was excellent for both groups. Pulmonary artery pressure, pulmonary vascular resistance, and carbon dioxide tension were not significantly different between the groups immediately or on day 3.

Animals↗
PubMed1989

A prospective study of adjuvant surgical resection after chemotherapy for limited small cell lung cancer. A University of Toronto Lung Oncology Group study.

Seventy-two patients with limited small cell lung cancer were identified as candidates for adjuvant operation after chemotherapy. All patients received preoperative chemotherapy with cyclophosphamide, doxorubicin HCl (Adriamycin), and vincristine, or the epipodophyllotoxin derivative VP-16 and cisplatin. The rate of response to chemotherapy was 80% (complete response 38% and partial response 42%). After chemotherapy, 57 patients (79.1%) were candidates for adjuvant surgical resection, but only 38 underwent thoracotomy. Eight required a pneumonectomy, 25 a lobectomy, and five patients had no resection. Postoperative pathologic study revealed only small cell lung cancer for 29 patients, mixed and non-small cell lung cancer for two, non-small cell lung cancer for four, and no residual tumor in three patients. Pathologic staging revealed seven patients in stage I (N0), nine in stage II (N1), and 22 in stage III. The median survival time for the 38 surgical patients was 91 weeks and projected 5-year survival rate 36%. Patients with pathologic stage I disease had significantly longer survival times (median not reached) than did patients in stage II or stage III (median survival 69 and 52 weeks, respectively). Within the group not undergoing operation, 19 patients responded to therapy and were eligible for adjuvant surgical resection, but did not undergo thoracotomy (10 patients were randomized to radiation only, and nine patients refused operation). Their median survival of 51 weeks was inferior to that of the 38 surgical patients (p = 0.049). Adjuvant surgical resection after chemotherapy resulted in long-term survival and cure for a significant proportion of patients with pathologic stage I disease. A significant improvement in survival could not be documented for patients in stages II and III. Intensive pretreatment investigation including mediastinoscopy is essential to exclude patients who will not benefit from adjuvant surgical resection.

Adult↗
PubMed1989

Transhiatal esophagectomy with gastric transposition for pharyngolaryngeal malignant disease.

Between 1981 and 1988, 41 patients underwent pharyngolaryngoesophagectomy with transhiatal gastric transposition and primary pharyngogastrostomy for hypopharyngeal, laryngeal, and cervical esophageal carcinoma. All patients had squamous cell carcinoma. Twenty-one patients had been treated initially by high-dose radiotherapy, but the tumor had either persisted or recurred. Four patients had previously received high-dose local radiotherapy to the neck for unrelated diseases, and in 16 patients no preoperative radiotherapy was given. There was one operative death. Anastomotic leaks developed in nine previously irradiated patients and three required flap reconstructions. Thirty patients had satisfactory swallowing postoperatively and three swallowed poorly. Delayed gastric emptying was a serious problem in two patients, necessitating pyloric bag dilatation in one and pyloroplasty in another. The average postoperative stay was 31 days. Thirty-seven percent survived longer than 12 months and 15% longer than 24 months. The probability of survival after 2 years is 35%. All deaths from recurrent disease occurred within 412 days postoperatively. At present, pharyngolaryngoesophagectomy with gastric transposition and primary pharyngogastric anastomosis offers the best chance for cure or palliation with acceptable morbidity and function for selected patients with advanced hypopharyngeal and laryngeal tumors.

Adult↗
PubMed1988

Technique of successful clinical double-lung transplantation.

Lung transplantation has become a successful method in the therapy for end-stage pulmonary disease. While single-lung transplantation provides benefit to patients with pulmonary fibrosis, bilateral lung transplants are required for septic or emphysematous lung disease. We describe the technique employed in 6 patients to transplant en bloc both lungs with the recipient heart left in place. The lungs are connected by a left atrial cuff, main pulmonary artery, and trachea. The completed implantation has a tracheal anastomosis securely wrapped in omentum, a left atrial anastomosis posterior to the heart, and a pulmonary artery anastomosis anteriorly. Airway ischemia resulted in the death of 1 patient. This procedure allows complete excision of all diseased pulmonary tissue, retention of the recipient's own heart, and separate excision of the donor heart for use in another recipient, thereby markedly increasing the supply of donor lungs for transplantation.

Adolescent↗
PubMed1988

Separate extraction of cardiac and pulmonary grafts from a single organ donor.

The scarcity of multiple-organ donors for perfused organ transplantation requires cooperation between various transplanting teams to maximize organ retrieval. We have developed a technique for the extraction of a cardiac and separate pulmonary graft from the same donor. These grafts can then be successfully implanted into two separate recipients. Our experience with 9 successful extractions and implantations is recorded.

Anastomosis, Surgical↗
PubMed1988

Status of lung transplantation.

Selected patients with terminal lung disease have been managed effectively by lung transplantation. Strict selection criteria for donors and recipients, attention to technical detail, and avoidance of perioperative corticosteroids increase the likelihood of success. The underlying pulmonary disease determines the appropriate procedure. Single-lung transplantation is most appropriate for patients with pulmonary fibrosis. Patients with emphysema or septic pulmonary disease who have adequate or recoverable cardiac function can be well served by double-lung transplantation. However, such patients are still treated in some centers by combined heart-lung transplantation. Patients with right-heart failure secondary to vascular or parenchymal pulmonary disease are best managed by combined heart-lung transplantation. Donor availability, airway healing, and diagnosis of rejection remain significant problems and are the focus of experimental and clinical investigation in many centers.

Graft Rejection↗
PubMed1988

Adjuvant chemotherapy following surgical resection for small-cell carcinoma of the lung.

Surgery alone is inadequate therapy for limited small-cell lung cancer (SCLC), resulting in less than 5% long-term survival. Since 1976, we treated patients undergoing surgery for SCLC with adjuvant chemotherapy in an attempt to prolong survival and increase cure. Seventy-seven patients who underwent surgery as their primary treatment were identified, and of these 63 (46 male and 17 female) received chemotherapy. Fifteen patients had a pneumonectomy, 46 a lobectomy, and two had wedge resections. Six patients had positive microscopic resection margins. Pathologic staging showed tumor, node, metastasis (TNM) involvement as follows: T1N0, eight; T2N0, ten; T1N1, six; T2N1, 18; T1N2, five; T2N2, nine; T3N0, three; T3N1, one; and T3N2, three. All patients received cyclophosphamide, Adriamycin (doxorubicion; Adria Laboratories, Mississauga, Ontario), and vincristine; four also received etoposide (VP-16) and cisplatin, one VP-16, and four methotrexate, procarbazine, and lomustine (CCNU). Forty-nine patients received prophylactic cranial irradiation, and 35 received radiotherapy to the mediastinum and primary site. The overall median survival of the 63 patients is 83 weeks, and the projected 5-year survival is 31%. Patients with T1 or T2 tumors without nodal involvement had a median survival of 191 weeks, and projected 5-year survival of 48%. Stage II (T1N1, T2N1) and stage III (any T3 or T1-2N2) patients had median survivals of 72 weeks and 65 weeks, and projected 5-year survivals of 24.5% and 24%, respectively. Thirty-three patients have relapsed and died of disease. Only two patients had an isolated relapse at the primary site. Seven other patients have died without recurrent disease. Adjuvant chemotherapy after surgery results in prolonged survival and cure for a significant number of patients with stage I SCLC, although nodal involvement at any level is associated with shorter survival.

Adult↗
PubMed1988

A new model for assessment of lung preservation.

No completely satisfactory experimental model exists to compare different techniques of preservation currently used in the distant procurement of a lung allograft. A canine model of left lung transplantation is described in which an inflatable cuff is placed around each pulmonary artery. Each cuff is connected to a subcutaneous reservoir, which allows alternate occlusion of either pulmonary artery. Functional assessment of lung function is made during ventilation of both lungs and after a 10-minute period of perfusion to the native lung alone and then to the transplanted lung alone. Systemic and pulmonary artery pressures are recorded continuously, and measurement of arterial blood gases and oxygen uptake are made immediately after the operation and again at 3 days. The animal is then put to death and the lungs are excised and weighed. Five dogs underwent transplantation of the donor lung immediately after excision (mean ischemic time = 55 +/- 7 minutes). Similar values for oxygen tension and oxygen uptake were obtained postoperatively for the right lung (oxygen tension = 420 mm Hg, oxygen uptake = 101 ml/min) and the left lung (oxygen tension = 368 mm Hg, oxygen uptake = 108 ml/min). However, carbon dioxide tension was elevated (right lung = 41 mm Hg, left lung = 52 mm Hg). Mean pulmonary artery pressure increased during allograft perfusion (right lung = 14 mm Hg, left lung = 24 mm Hg), although systemic blood pressure was unchanged. Similar results were observed at 3 days. The mean weight of the native lung was 101 +/- 2 gm and that of the transplanted lung, 128 +/- 6 gm. This model achieves consistent survival and allows serial observations of the functional adequacy of an allograft compared with a normal contralateral lung.

Animals↗
PubMed1988

[Lung transplantation].

In this summary of his verbal communication, G.A. Patterson develops the reasons which have prompted the Toronto group to perform unilateral or bilateral lung transplantations. The author also briefly presents the results obtained by his group in these two types of lung transplantation and in heart-lung transplantation.

Heart Transplantation↗
PubMed1988

Experimental and clinical double lung transplantation.

We have previously demonstrated the technical feasibility of an en bloc double lung transplantation in acute canine experiments. We have now conducted survival experiments in cynomolgus monkeys. Profound hypothermia and circulatory arrest were used to avoid the need for cardiopulmonary bypass in these very small animals. Because of the complexities of this technique, few long-term survivals resulted, but these experiments did confirm excellent lung function and satisfactory tracheal healing. On the basis of these experiments, we have performed our first clinical double lung transplantation on a 42-year-old woman with end-stage emphysema caused by alpha 2-antitrypsin deficiency. The patient has returned to normal activities with excellent lung function.

Adult↗
PubMed1988

Esophagectomy for complex benign esophageal disease.

We evaluated the use of total thoracic esophagectomy and replacement with stomach in a group of 21 patients between 1976 and 1986 who had undergone multiple unsuccessful esophageal operations. All patients had between one and four unsuccessful operations for benign esophageal disorders. Sixteen patients had primary motor disorders: achalasia in nine and esophageal spasm in seven. Of these patients, 11 also had recurrent gastroesophageal reflux and peptic esophagitis. Complicated reflux disease characterized by severe esophagitis, stricture, and impaired peristalsis without primary motor disorder occurred in five patients. In one patient a functionally impaired long-segment colon interposition was removed and replaced with stomach. Total thoracic esophagectomy and cervical esophagogastric reconstruction was done in all patients. The transhiatal approach was chosen for resection in 16 patients and thoracotomy was used in the other five. There was one perioperative death (5%), from massive aspiration 4 days after transhiatal esophagectomy. Other complications included transient anastomotic leak (three patients), tracheoesophageal fistula (one), recurrent nerve palsy (one), and transient hoarseness (two). Follow-up is complete between 1 and 10 years and reveals the following functional results: 12 patients good to excellent, seven fair, one poor. In this patient group in which multiple prior procedures have failed to improve severe incapacitating symptoms, we believe further attempts at hiatal reconstruction are unlikely to succeed. For this circumstance, we recommend total thoracic esophagectomy with the use of stomach as the replacement organ of choice.

Adult↗
PubMed1987

Significance of metastatic disease in subaortic lymph nodes.

Thirty-five patients underwent resection of primary bronchogenic carcinoma of the left upper lobe or left main bronchus in the presence of metastatic disease in subaortic lymph nodes. No patient had metastatic disease in other mediastinal node stations. There was 1 postoperative death. Complete follow-up is available on 34 patients. Three-year and five-year actuarial survival for the entire group is 44% and 28%, respectively. For 23 patients undergoing complete resection, five-year actuarial survival is 42%. Resection of primary bronchogenic carcinoma in the presence of subaortic nodal metastases is associated with improved survival relative to reports of survival following resection of metastatic disease in other mediastinal node stations. Resection should be undertaken in these patients especially when it is judged that the resection is likely to be complete.

Adult↗