Duration of knowledge in general thoracic surgery.

BACKGROUND: Medical knowledge changes rapidly, so current medical education approaches emphasize the development of life-long learning skills ("teaching the learner to learn") as opposed to the simple acquisition of contemporary medical knowledge. Because there are no data on the rapidity of change of general thoracic surgical knowledge, we do not know whether this trend in medical education is appropriate for thoracic surgical trainees. We undertook a study to assess the duration of knowledge in general thoracic surgery. METHODS: The first general thoracic surgery article from each issue of The Annals of Thoracic Surgery between 1965 and 1997 was abstracted into a summary statement. A form, made up of 360 summary statements in random order, was assessed by 6 general thoracic surgeons. They assessed statement validity on a 5-point scale (1 = statement false; 5 = statement true). Average statement validity scores for 30 time intervals were calculated. The relationship between time of publication and statement validity was analyzed. RESULTS: Average validity scores ranged from 2.24 (represents 1965 to 1966) to 4.32 (represents 1969 to 1970). Validity scores increased with time (y = 3.46 + 0.017x, where y is validity score and x is time), and this was significant (r = 0.40; p = 0.027). However, the absolute change in average validity scores over the 33-year study period was only 0.52 or 13.1% of the "modern" era scores. CONCLUSIONS: The assumption that medical knowledge changes quickly may not be true in general thoracic surgery. Although life-long learning skills are important, general thoracic surgery training programs should continue to emphasize fundamental knowledge in the specialty.

Bronchogenic carcinoma in patients age 30 and younger.

BACKGROUND: Lung cancer is rare in patients 30 years of age or younger. There is very little published data on lung cancer in this group of patients. METHODS: A retrospective review of patients 30 years of age and younger with bronchogenic carcinoma treated at Roswell Park Cancer Institute between 1973 and 1994 was done. RESULTS: There were 20 patients (11 female and 9 male). Mean age was 27 years (range, 19-30). The predominant histologic types were adenocarcinoma in 11 patients (55%), and undifferentiated large-cell carcinoma in 5 patients (25%). All patients presented with either stage III (8 patients) or IV disease (12 patients). Eight patients (40%) underwent surgical resection (2 lobectomies, 6 pneumonectomies). Other treatments included chemotherapy in 15 patients (75%) and radiation therapy in 7 (35%). Median survival was only 5.5 months, and there were no 5-year survivors. Univariate analysis identified stage (p = 0.05), resection (p = 0.0005), and treatment with chemotherapy (p = 0.001) as predictors of survival. On multivariate analysis, resection (p = 0.0001) and chemotherapy (p = 0.001) remained as independent predictors of survival. CONCLUSIONS: Young patients with lung cancer present with advanced-stage disease and their cancers appear to be biologically aggressive. Although curative treatment is rarely possible, aggressive multimodality therapy is warranted.

A 25-year thymoma treatment review.

Most thymomas are stage I or II at presentation, and they have a good prognosis with surgical treatment. Higher stage thymomas are less common and their treatment is more problematic. Our center tends to attract patients with higher stage thymomas for treatment. We reviewed our experience and contrasted it with other published series. A 25-year retrospective record review of thymomas was done. 38 patients were treated. Median age was 49 years. Four had myasthenia gravis. Masaoka staging was: stage I--9; stage II--6; stage III--15; stage IVa--4; stage IVb--4. Resection was done in 25 patients (21 had R0 resection), chemotherapy was given to 15 patients, and 27 patients received radiotherapy. Overall median survival was 55 months. Overall 5 and 10-year survivals were 30% and 18%. 5-year survival by stage was: stage I--75%; stage II--50%; stage III/IV--23%. Negative prognostic factors on univariate analysis included presence of symptoms at presentation (p = 0.02), unresectable tumor (p = 0.06), stage III/IV (p = 0.04), and disease recurrence after resection (p = 0.0001). On multivariate analysis, only stage (p = 0.04) and recurrence (p = 0.0001) were independent predictors of survival. All patients who recurred after resection eventually died of disease. Our overall treatment results are disappointing, but we had higher stage patients than reported by most other centers. Early stage thymomas are suitable for complete surgical resection, and the prognosis is favorable. However, higher stage thymomas (stage III and higher) pose problems for complete surgical resection and their prognosis is poor. Newer multimodality treatment approaches are indicated for higher stage thymomas.

Bronchogenic carcinoma in young patients.

BACKGROUND AND OBJECTIVES: Some investigators have suggested that lung cancer in young patients has a more aggressive course and poorer prognosis than lung cancer in older patients. METHODS: A retrospective review is presented of patients less than 40 years of age with bronchogenic carcinoma treated at Roswell Park Cancer Institute between 1984 and 1994, with comparison to a cohort of patients treated in the previous decade. RESULTS: There were 76 patients (41 male and 35 female). Mean age was 35 years (range, 26-39). Adenocarcinoma in 33 patients (43%) and undifferentiated large-cell carcinoma in 22 patients (29%) were the predominant histologic types. Stage IIIa or greater disease was present in 63 (83%) patients. Treatment consisted of chemotherapy (55 patients), radiation therapy (54 patients), and surgery (33 patients). Surgical procedures included pneumonectomy (14 patients), lobectomy (11 patients), wedge resection (1 patient), and thoracotomy only for unresectable disease (7 patients). Operative mortality was 6% (two patients who had radical pneumonectomy for T4 cancer). Median survival for the entire group of patients was 10.4 months, and 5-year survival was 8%. Univariate analysis identified acute presentation (P = 0.02), no resection (P = 0.0001), and higher stage (P = 0.0001) as negative prognostic factors. On multivariate analysis, stage of disease was the only independent predictor of survival (P = 0.005). Resectability was slightly higher (34%, 26/76, vs. 21%, 19/89; P = 0.06) and survival was marginally better (median 10.4 vs. 7.5 months; P = 0.05) than that seen at our institution in the previous decade. CONCLUSIONS: Young patients with lung cancer often have advanced disease at the time of presentation. Nevertheless, they should be treated in accordance with standard stage-specific treatment guidelines.

Primary tumors of the mediastinum.

BACKGROUND AND OBJECTIVES: Diagnostic and therapeutic approaches to mediastinal tumors have changed over the past three decades. We reviewed our recent experience with these tumors and assessed the role of a multidisciplinary treatment approach. METHODS: A retrospective review of 124 patients with primary mediastinal tumors over a 25-year period. RESULTS: Median age was 35 years. Symptoms were present in 86 of 124 (69%) patients. One hundred and eleven of 124 (90%) tumors were malignant. Distant metastases were present at diagnosis in 14 of 124 (11%) patients. The most common tumor was thymoma (38/124, 31%), followed by germ-cell tumor (29/124, 23%), lymphoma (24/124, 19%), and neurogenic tumors (15/124, 12%). Seventy-four of 124 (60%) patients underwent resection, 88 (71%) received chemotherapy, and 97 (78%) received radiation therapy. Tumor recurrence occurred in 52% (47/91) of patients who initially had a complete resection or response to treatment. Median time to recurrence was 10 months. Overall median survival was 44 months. Metastatic disease at presentation (P = 0.02) and tumor recurrence (P = 0.00001) were the only significant independent predictors of survival on multivariate analysis. CONCLUSIONS: Malignant primary mediastinal tumors often require multimodality treatment. Despite improvements in survival with multimodality treatment, death from recurrent disease remains a problem.

Metachronous benign solitary fibrous tumours of the pleura (localized "mesotheliomas"): a case report.

Solitary fibrous tumours are uncommon pleural tumours that are not related to mesotheliomas. They are typically benign and pedunculated and may grow to massive sizes. Surgical resection is usually curative. Tumour recurrence and metachronous development of multiple tumours are unusual. In this report a patient was treated for 3 benign solitary fibrous tumours of the pleura over 23 years. The authors hypothesize that this represents multifocal tumorigenesis as opposed to local tumour recurrence. The importance of complete surgical excision and lifelong radiographic follow-up are stressed.

Operation and photodynamic therapy for pleural mesothelioma: 6-year follow-up.

BACKGROUND: Conventional therapy for pleural mesothelioma has met with disappointing results. METHODS: From 1991 to 1996, 40 patients with malignant pleural mesothelioma were treated with surgical resection followed by immediate intracavitary photodynamic therapy. RESULTS: The series included 9 women and 31 men with a mean age of 60 years. Morbidity and treatment-related mortality rates for the entire series, pleurectomy, and extrapleural pneumonectomy were 45% and 7.5%, 39% and 3.6%, and 71% and 28.6%, respectively. Median survival and the estimated 2-year survival rate for the entire series, stages I and II patients (n = 13), and stages III and IV patients (n = 24) were 15 months and 23%, 36 months and 61%, and 10 months and 0%, respectively. Multivariate analysis identified stage, length of hospital stay, photodynamic therapy dose, and nodal status as independent prognostic indicators for survival. CONCLUSIONS: Surgical intervention and photodynamic therapy offer good survival results in patients with stage I or II pleural mesothelioma. For patients in stage III or IV, better treatment modalities need to be developed. Improvements in early detection and preoperative staging are necessary for proper patient selection for treatment.

Prognostic implications of pulmonary satellite nodules: are the 1997 staging revisions appropriate?

In the 1992 AJCC and 1993 UICC staging systems, primary lobe satellite nodules increased the T designation of the primary by one level and ipsilateral non-primary lobe satellite nodules raised the T designation to T4. The recent 1997 UICC and AJCC staging revisions assign a T4 (IIIb) designation to satellite nodules in a primary lobe, and a M1 (IV) designation to satellites in ipsilateral non-primary lobes. There is abundant evidence showing that satellite nodules are negative prognostic factors, but their inclusion in stage IIIb and IV may not be appropriate. The English-language medical literature was searched for papers reporting survival after surgical resection of lung cancer with satellite nodules (primary and non-primary ipsilateral lobe locations). Eleven articles were retrieved and their data pooled for analysis. Of 568 resected patients with satellite nodules, actuarial 5-year survival was 20%. Five articles gave separate survival data for satellite nodules in primary versus ipsilateral non-primary lobes. All five articles showed better survival for satellite nodules in a primary lobe. Satellite nodules in a primary lobe have a better prognosis than those in ipsilateral non-primary lobes. Survival for resected lung cancer with satellite nodules in a primary lobe is better than that usually observed for T4 (IIIB) disease. The 1997 staging revisions may unduly upstage patients with satellite nodules in a primary cancer lobe. However, satellite nodules in ipsilateral non-primary lobes share metastatic mechanisms and have survival results consistent with M1 stage disease. Their 1997 MI designation may be appropriate.

Malignant pleural mesothelioma: a problematic review.

Malignant pleural mesothelioma is a rare tumor that has been difficult to study. Because of disappointing treatment results, malignant pleural mesothelioma has remained an area of active research and development. A clinicopathologic review is performed in light of several problematic issues involving diagnosis, staging, natural history, and treatment. Multimodality treatment with surgery followed by adjuvant local and systemic therapy remains the most optimal therapy. Many controversial issues still exist in the treatment of malignant pleural mesothelioma. In the ensuing years newer staging systems, better preoperative staging, newer experimental therapies, and the localization of patients at expert centers will undoubtedly have an impact on disease management.

The effect of ischemic conditioning on gastric wound healing in the rat: implications for esophageal replacement with stomach.

BACKGROUND: Esophagectomy, with gastric pull up replacement, is not uncommonly complicated by leakage from the esophagogastrostomy anastomosis. Occult ischemia of the mobilized gastric fundus is a major etiological factor for anastomotic leakage. Gastric tissue perfusion can be improved by ischemic conditioning ("delay" phenomenon). OBJECTIVE: To test the hypothesis that ischemic conditioning will improve gastric wound healing, and reduce the incidence of anastomotic dehiscence, in a rodent model of partial gastric devascularization. EXPERIMENTAL DESIGN: Laboratory study of gastric wound healing in rats. ANIMALS: Forty-five Sprague-Dawley rats (3 groups of 15 rats). INTERVENTIONS: All animals underwent laparotomy on day 0. Group 1 (control) and group 3 (acute ischemia) rats had sham laparotomies done. Group 2 (ischemic conditioning) rats underwent laparotomy and left gastric artery ligation. On postoperative day 14, all animals underwent repeat laparotomy; gastrotomy wounds were created and sutured. Group 1 (control) and group 2 (ischemic conditioning) rats had gastrotomy alone, while group 3 (acute ischemia) rats also underwent left gastric artery ligation. All rats were sacrificed 5 days after gastrotomy and wound healing was assessed. MEASURES: Gastrotomy wounds were assessed for dehiscence, bursting strength, and hydroxyproline concentration. RESULTS: Anastomotic dehiscence did not occur in group 1 (control) or group 2 (ischemic conditioning) rats. Four of 15 rats (27%) in group 3 (acute ischemia) suffered anastomotic dehiscence (p = 0.028). Wound bursting pressure in the three groups was not significantly different (group 1--96.3 +/- 8.3 mmHg, group 2--91.1 +/- 4.8 mmHg, group 3--70.9 +/- 12.7 mmHg, p = 0.13). Wound hydroxyproline concentration in the control group was significantly higher than in the other 2 groups (group 1--0.124 +/- 0.005 mumol/mg, group 2--0.113 +/- 0.007 mumol/mg, group 3--0.102 +/- 0.006 mumol/ mg, p = 0.04), but there was no difference between the acute ischemia and the ischemic conditioning groups (p = 0.24). CONCLUSIONS: In this rodent model of partial gastric devascularization, ischemic conditioning reduced the incidence of anastomotic dehiscence. Wound bursting strength and hydroxyproline concentration were not affected by ischemic conditioning. Therefore, the harmful effect of ischemia, and the beneficial effect of ischemic conditioning, are probably not primarily related to synthesis of wound collagen. Ischemic conditioning of the stomach is a concept that may prove clinically useful in reducing the incidence of leakage from esophagogastrostomy anastomoses.

Gastric distention exacerbates ischemia in a rodent model of partial gastric devascularization.

Occult ischemia of the mobilized gastric fundus is an important etiologic factor for esophagogastric anastomotic leaks after esophagectomy. Postoperative gastric distention is another possible predisposing factor for anastomotic leakage. We hypothesized that gastric distention could worsen gastric ischemia. To test this hypothesis, gastric tissue perfusion was studied in 20 Sprague-Dawley rats. Baseline serosal gastric tissue perfusion was measured by laser-Doppler flowmetry at a point 10 mm distal to the gastroesophageal junction. Perfusion was measured after left gastric artery occlusion, gastric distention to 20 cm water pressure, and combined left gastric artery occlusion and gastric distention. Gastric tissue perfusion (in tissue perfusion units, TPU) was 64.2 +/- 9.1 TPU at baseline measurement, 18.6 +/- 4.3 TPU after left gastric artery occlusion, 22.0 +/- 4.1 TPU after gastric distention, and 7.8 +/- 1.8 TPU after combined left gastric artery occlusion and gastric distention. Distention (P < 0.0001) and arterial occlusion (P < 0.0001) both reduced gastric tissue perfusion; of the two, arterial occlusion produced the greatest reduction in perfusion (P < 0.021). The combination of distention and arterial occlusion caused greater reduction in gastric perfusion than either factor alone (P < 0.0001). In this model, gastric distention exacerbated the ischemia produced by partial gastric devascularization. In clinical esophageal surgery, postoperative gastric distention may similarly potentiate the ischemic effects of gastric transposition for esophageal reconstruction.

Necrotizing soft tissue infections of the chest wall.

BACKGROUND: Necrotizing soft tissue infections of the chest wall are uncommon, and they have received little discussion in the medical literature. METHODS: We performed a collective review of the literature to summarize information on etiology, prevention, treatment, complications, and outcome of chest wall necrotizing soft tissue infections. Manual, Medline, and Current Contents searches of the English-language medical literature were done. RESULTS: There were 9 reported cases of necrotizing soft tissue infection of the chest wall. Eight were complications of invasive procedures and operations. Tube thoracostomy for empyema (4 patients) was the most common antecedent procedure. Excessive soft tissue dissection during chest tube insertion was implicated in the genesis of these infections. Necrotizing infections complicated esophageal operations in 2 patients. Overall mortality was 89%. Only 3 of the 9 patients underwent early and adequate debridement. Chest wall stability and wound reconstruction were problematic in patients who survived the initial septic illness. CONCLUSIONS: Necrotizing soft tissue infections of the chest wall are highly lethal infections that require urgent and aggressive debridement. Diagnostic delay and inadequate debridement are common reasons for treatment failure. Repetitive surgical debridement is often needed to control sepsis. Wound closure is challenging in patients who survive the initial septic phase of their illness.

Ischemic conditioning (delay phenomenon) improves esophagogastric anastomotic wound healing in the rat.

BACKGROUND AND OBJECTIVES: Esophagogastric anastomotic leaks are a major source of morbidity after esophagectomy. Occult ischemia of the mobilized gastric fundus is an important etiological factor for this failure of healing. To test the hypothesis that ischemic conditioning (delay phenomenon) could improve esophagogastric anastomotic healing, anastomotic healing was studied in a rodent model of partial gastric devascularization. METHODS: Thirty-four Sprague-Dawley rats (two groups of 17 rats) underwent partial gastric devascularization and creation of esophagogastric anastomoses. In the acute ischemia group, devascularization and anastomosis were done at the same laparotomy. In the ischemic conditioned group, devascularization was done 3 weeks before anastomosis. Gastric tissue perfusion was assessed by laser-Doppler flowmetry before and after devascularization in both groups, and 3 weeks after devascularization in the ischemic conditioned group. All rats were killed 4 days after anastomosis, and the wounds assessed for dehiscence, breaking strength, and hydroxyproline concentration. RESULTS: Gastric tissue perfusion, measured in tissue perfusion units (TPU) decreased immediately after devascularization (before: 73.6 +/- 12.1 TPU; after: 25.0 +/- 6.5 TPU; P < 0.001). After 3 weeks, gastric tissue perfusion returned to baseline values in the ischemic conditioned rats (before: 72.3 +/- 11.0 TPU; 3 weeks, 71.1 +/- 15.1 TPU; P < 0.80). Ischemic conditioned rats had fewer anastomotic leaks (2 vs. 9, P < 0.023) and higher anastomotic wound breaking strengths (2.35 +/- 1.05 N vs. 1.56 +/- .76 N, P < 0.02) than the acute ischemic rats. Anastomotic would hydroxy-proline concentration was not significantly different in the two groups (acute ischemic--0.111 +/- .033 mumol/mg, ischemic conditions--0.097 +/- .026 mumol/mg, P < 0.20). CONCLUSIONS: In this rodent model of partial gastric devascularization, ischemic conditioning (delay phenomenon) ameliorated the harmful effect of ischemic on esophagogastric anastomotic wound healing.

Long-term outcome after pneumonectomy for nonsmall cell lung cancer.

Long-term survivors (5 or more years) of pneumonectomy for nonsmall cell lung cancer are at risk for late death from cancer recurrence, second primary malignancies, and cardiopulmonary insufficiency related to the adverse physiological effects of pneumonectomy. A retrospective study of pneumonectomy patients was done to quantify the risks of late death from these causes. Of 246 patients treated for nonsmall cell lung cancer by pneumonectomy, medical records of 49 who survived 5 or more years were reviewed. Follow-up for the 49 long-term survivors ranged from 60 to 240 months, with a mean of 113 months. Twenty-five (51%) of the long-term survivors were alive at the time of the study. Twenty-four (49%) had died. Causes of death included late lung cancer recurrence (6 patients), second primary malignancies (7 patients), cardiopulmonary insufficiency (4 patients), and miscellaneous causes unrelated to cancer and its treatment (7 patients). Long-term survival after pneumonectomy for nonsmall cell lung cancer occurs in 20% of patients. Late lung cancer recurrence and second primary malignancies are important causes of death in these patients. Late cardiopulmonary insufficiency related to adverse physiological consequences of pneumonectomy is uncommon. Long-term follow-up is recommended after pneumonectomy for nonsmall cell lung cancer.

Herpes simplex viral pneumonia in the postthoracotomy patient.

Over a 6-month period, 6 of 54 postthoracotomy patients developed pneumonia and respiratory failure. Pneumonia was secondary to herpes simplex virus type 1 in 3 of the 6 patients. Diagnostic efforts including bronchoscopy with bronchial washing, viral cultures, and cytologic examination permitted early diagnosis and successful treatment with acyclovir. A high index of suspicion for herpes simplex pneumonia must be maintained in critically ill patients with undiagnosed pneumonia.

Operation and intracavitary photodynamic therapy for malignant pleural mesothelioma: a phase II study.

From April 1991 to May 1993, 23 patients entered a phase II clinical study of surgical resection and adjuvant intracavitary photodynamic therapy for malignant pleural mesothelioma. Two days preoperatively, patients received an intravenous injection of 2 mg/kg of the photosensitizer Photofrin. Six patients underwent a pleuro-pneumonectomy, and 15 patients a pleurectomy, after which intracavitary photodynamic therapy was administered. A total light energy dose of 20 to 25 J/cm2 was given. In 2 patients the tumor was unresectable due to intrapericardial invasion. Postoperative complications were noted in more than 50 percent of patients; 2 patients died of postoperative complications. Postoperative survival was analyzed according to intraoperative staging proposed by the American Joint Committee for Cancer Staging, published in 1992. The overall estimated median survival is 12 months; that of stage III and IV patients is 7 months. Five patients with stage I and II diseases (who had grossly complete resection by pleurectomy) are alive, disease-free, for 11, 17, 18, 21, and 33 postoperative months. Intraoperative staging is important in carrying out further clinical studies of malignant pleural mesothelioma.

Neurilemmoma of the diaphragm.

Diaphragmatic neurilemmomas are rare tumors. We report here such a case and also review five cases from the English-language medical literature. Neurilemmomas of the diaphragm are benign tumors that display slow, progressive growth. They remain encapsulated and do not invade adjacent structures. Surgical resection is both diagnostic and therapeutic. Thoracotomy is the operative approach of choice.