The diaphragm.

This article discusses the diaphragm from a surgical perspective. Although it is a relatively simple organ compared with other structures, the diaphragm serves important anatomic and functional roles necessary for proper respiratory function. It is an organ of little irregularity or disease, and easily manipulated in the operating room by those who have a basic understanding of its anatomic details.

Video-assisted thoracic surgery (VATS) as a safe alternative for the resection of pulmonary metastases: a retrospective cohort study.

BACKGROUND: VATS has become a preferred method for benign surgical conditions, yet still remains controversial for malignancies. The purpose of this study was to review our results of pulmonary metastasectomies using both conventional open thoracotomy and VATS techniques. METHODS: This is a retrospective chart review of pulmonary metastasectomies performed from 1986 to 2006. The surgical approach used for the initial pulmonary metastasectomy was either open thoracotomy or VATS. Main outcomes were overall survival and recurrence free survival, evaluated using Kaplan Meier analysis. A non-inferiority margin was set at 0.2. RESULTS: A total of 280 surgical procedures were performed on 186 patients. From 171 eligible individuals, 135 patients were treated with thoracotomy (82 M, 53 F; median age 49 years), and 36 with VATS (18 M, 18 F; median age 58.5 years). Primary cancers were mainly: 81 sarcoma (47%), 26 colorectal adenocarcinoma (15%) and 22 renal cell carcinoma (13%). Median postoperative follow was 26.2 months. The conversion rate was 10.3% and there were no cases of pleural cavity seeding. The 5-year overall survival rates were 58.8% for thoracotomy and 69.6% for VATS, with median overall survival of 53.2 months and 30.1 months, respectively (p = 0.03). The estimated difference in 5-year overall survival was 10.8%. Second occurrences were noted in 59 thoracotomy and 10 VATS patients. The 5-year recurrence free survival rates were 51% in thoracotomy and 67% in VATS (p = 0.27), with median recurrence free survival of 24.8 months and 25.6 months, respectively. CONCLUSION: In cases of pulmonary metastases, VATS is an acceptable alternative that is both safe and efficacious. Non-inferiority analysis of 5-year overall survival demonstrates that VATS is equivalent to thoracotomy. VATS patients also have a longer recurrence free survival. Based on our experience, it is permissible to use VATS resection in these circumstances: small tumor, fewer nodules, single lesion, age < or = 53, unilateral, tumor size amenable to wedge resection, and non-recurrent disease.

Video-assisted thoracic surgery (VATS) for resection of metastatic adenocarcinoma as an acceptable alternative.

BACKGROUND: Adenocarcinomas commonly metastasize to the lungs and can be resected using open thoracotomy or video-assisted thoracic surgery (VATS). This study reviews metastatic resections in primary adenocarcinoma patients, using both thoracotomy and VATS. We aim to compare long-term prognoses to test the efficacy and viability of VATS. METHODS: A retrospective review of primary adenocarcinoma patients who underwent resection of pulmonary metastases from 1990 to 2006 was carried out. Information was obtained by chart review. Endpoints analyzed were disease-free interval (DFI), survival time, and recurrence-free survival (RFS). RESULTS: In a total of 42 (16 male, 26 female; median age 58.5 years) primary adenocarcinoma patients, 21 patients underwent first pulmonary metastatic resection using VATS (7 male, 14 female; median age 57 years) and 21 using thoracotomy (9 male, 12 female; median age 59 years). Primary adenocarcinomas were mainly 27 colorectal (64%) and 11 breast (26%). Two VATS (10%) and three open patients (14%) had local recurrences of the original cancer. Median postoperative follow was 13.3 months [interquartile range (IQR) 4.5-32.8 months] for VATS and 36.9 months (IQR 19.3-48.6 months) after thoracotomy. Median DFI-1 was 22.3 months (IQR 13.5-40.6 months) for VATS patients and 35.6 months (IQR 26.7-61.3 months) for open patients. Second thoracic occurrences were noted in six VATS patients (median DFI-2 9.2 months), and in seven open patients (median DFI-2 21.5 months). Third thoracic occurrences were noted in one VATS patient (DFI-3 18.7 months) and in one thoracotomy patient (DFI-3 21.8 months). Odds ratio of recurrence showed 12.5% less chance of developing recurrence in VATS patients. Five-year RFS was 53% in VATS and 57% in thoracotomy patients. CONCLUSIONS: VATS has become a viable alternative to open thoracotomy for resection of pulmonary metastases. In cases of primary adenocarcinoma, VATS showed no increase in number of thoracic recurrences, and comparable RFS. Short-term follow-up is encouraging; long-term follow-up will be needed to confirm these results.

Indications and technique of colon and jejunal interpositions for esophageal disease.

Esophageal replacement is a significant undertaking for both surgeon and patient. Because eating and drinking are some of life's great pleasures, the outcome of this undertaking has a direct impact on a patient's quality of life. The primary esophageal replacement organs are the stomach and colon, and each has advantages and disadvantages. As such, the choice of the graft should be tailored to the patient and the disease process in order to maximize the likelihood that the disease will be effectively treated, and that the patient's ability to enjoy a meal with family and friends will be restored.

Comparison of three myofibroblast cell sources for the tissue engineering of cardiac valves.

The objective of this study was to evaluate the capacity of three clinically useful tissue sources: tricuspid valve leaflet (TVL), carotid artery (CA), and jugular vein (JV), to generate myofibroblasts for potential use in a tissue-engineered cardiac valve replacement. Tissue biopsies of clinically appropriate sizes obtained from juvenile sheep were used for this work. Cells obtained from all three tissue sources exhibited a myofibroblast phenotype in vitro, as demonstrated by their immunoreactivity with antibodies directed against vimentin, alpha-smooth muscle actin, fibronectin, and chondroitin sulfate. Protein synthesis characteristics were defined for the key extracellular matrix components: collagen, glycosaminoglycans, and elastin. Among the three sources, JV generated the highest numbers of cells, and JV cells produced the largest amount of collagen per cell. These data suggest that venous tissue, with its relative ease of accessibility, may generate myofibroblasts potentially useful for the interstitial cellular component of a tissue-engineered cardiac valve.

Utility of PET, CT, and EUS to identify pathologic responders in esophageal cancer.

BACKGROUND: This study evaluates the utility of positron emission tomography (PET), endoscopic ultrasonography (EUS), and computed tomographic (CT) scans to predict pathologic response and survival following preoperative chemoradiation (CRT) in esophageal cancer. METHODS: One hundred three sequential patients with locoregionally advanced esophageal cancer, who were treated with CRT and esophageal resection between May 2001 and November 2003 at the University of Texas M.D. Anderson Cancer Center, were retrospectively reviewed. PET, EUS, and CT were performed before (pre) or after (post) CRT and before surgical resection. PET standardized uptake value (SUV) was defined as maximal uptake in primary tumor. RESULTS: Most patients were male (91 [88%]) with adenocarcinoma (90 [87%]). Pretreatment clinical stages were: IIA (42 [41%]), IIB (5 [5%]), III (50 [49%]), and IVA (6 [6%]). At the time of surgery, 58 patients (56%) had a pathologic response to CRT (< or =10% viable cells). Post-CRT measurements that correlated with pathologic response were: CT esophageal wall thickness (13.3 vs 15.3 mm, p = 0.04), EUS mass size (0.7 vs 1.7 cm, p = 0.01) and PET SUV (3.1 vs 5.8, p = 0.01). Post-CRT PET SUV equal to or greater than 4 had the highest accuracy for pathologic response (76%). Univariate and multivariate Cox regression analysis demonstrated that a post-CRT PET SUV equal to or greater than 4 was an independent predictor of survival (HR, 3.5, p = 0.04). CONCLUSIONS: The FDG-PET SUV is the most accurate noninvasive test to predict long-term survival after preoperative CRT and before surgical resection. Post-CRT FDG-PET cannot, however, rule out residual microscopic disease so esophagectomy should remain a therapeutic option even if the post-CRT imaging modalities are normal.

Endoscopic mucosal resection as a staging technique to determine the depth of invasion of esophageal adenocarcinoma.

BACKGROUND: Endoscopic ablation and vagal-sparing esophagectomy offer the potential for reduced morbidity in patients with high-grade dysplasia or early esophageal adenocarcinoma, but neither includes a lymphadenectomy. Although adequate for intramucosal tumors, both are potentially inadequate for patients with submucosal tumor invasion given the high prevalence of nodal metastases with these lesions. Currently there is no test including endoscopic ultrasound that can accurately determine whether a small tumor is confined to the mucosa or has penetrated into the submucosa. The aim of this study was to compare the pathologic depth of invasion by endoscopic mucosal resection with findings and outcome after surgical resection to assess the accuracy and reliability of endoscopic mucosal resection for staging early esophageal adenocarcinoma. METHODS: From 2001 to 2003, 7 patients presented with small, endoscopically visible adenocarcinomas. All underwent endoscopic mucosal resection followed by surgical resection. RESULTS: Analysis of the resected specimens confirmed that the endoscopic mucosal resection had accurately determined the depth of tumor invasion in all patients, and had completely excised the lesion in all but 1 patient (86%). Lymph node dissection was included as part of the resection in 2 patients with submucosal invasion by endoscopic mucosal resection, and a vagal-sparing esophagectomy was used in the 5 patients with only intramucosal tumors. All patients are alive and disease-free at a median follow-up of 7 months. CONCLUSIONS: Endoscopic mucosal resection accurately determines the depth of tumor invasion, and should be used as a staging procedure in patients with early esophageal cancer when therapies that do not include a lymphadenectomy are considered.

2-Fluoro-2-deoxy-D-glucose positron emission tomography imaging is predictive of pathologic response and survival after preoperative chemoradiation in patients with esophageal carcinoma.

BACKGROUND: The current study was performed to assess the value of 2-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) in predicting the pathologic response and survival of patients with esophageal carcinoma treated with preoperative chemoradiation (CRT) and tumor resection. Preliminary reports suggest that FDG-PET may be predictive of the response of esophageal carcinoma patients to preoperative CRT. METHODS: Eighty-three patients with resectable esophageal carcinoma who underwent preoperative CRT and FDG-PET and tumor resection were evaluated for pathologic response to CRT, percent residual tumor, and survival. RESULTS: The majority of patients in the current study were men (74 of 83 patients; 89%). Most tumors were adenocarcinomas (73 of 83 tumors; 88%) and clinical (EUS)T3/4 (69 tumors; 83%) or N1 (46 tumors; 55%). FDG-PET after preoperative CRT identified pathologic responders but failed to rule out microscopic residual tumor in 13 of 73 cases (18%). Pathologic response was found to correlate with the post-CRT FDG-PET standardized uptake value (SUV) (P = 0.03) and a post-CRT FDG-PET SUV of or 4 was found to be the only preoperative factor to correlate with decreased survival (2-year survival rate of 33% vs. 60%; P = 0.01). On univariate Cox regression analysis, only post-CRT FDG-PET was found to be correlated with post-CRT survival (P = 0.04). CONCLUSIONS: Post-CRT FDG-PET was found to be predictive of pathologic response and survival in patients with esophageal carcinoma who undergo preoperative CRT. Esophagectomy should still be considered even if the post-CRT FDG-PET scan is normal because microscopic residual disease cannot be ruled out.

Tricuspid valve biopsy: a potential source of cardiac myofibroblast cells for tissue-engineered cardiac valves.

BACKGROUND AND AIMS OF THE STUDY: As progress is made in the development of a tissue-engineered cardiac valve, the need for a reliable cell source is particularly important. A technique has been developed for the reliable biopsy of tricuspid valve leaflets. Expanding the harvested cells in culture is feasible and provides a source of leaflet cells that are structurally and functionally similar to the pulmonary and aortic valve leaflet cells that they may replace. METHODS: Thirteen sheep underwent tricuspid valve biopsy. Transthoracic echocardiography (TTE) was performed to evaluate function and guide the subsequent biopsy. Myofibroblasts were isolated from the biopsy samples, expanded in culture through 10 passages, and evaluated with immunocytochemistry for valve cell markers. Two animals were sacrificed acutely, two animals died during the immediate postoperative period, and nine animals survived for four weeks or more. RESULTS: All preoperative and pre-explantation echocardiograms were normal. Both animals sacrificed acutely showed that the tricuspid valve leaflet was indeed biopsied with this technique. Two perioperative deaths occurred; one animal died secondary to injury of the chorda tendinea with subsequent destruction of the posterior leaflet; another died from disruption of the superior vena cava that led to irreversible cardiac tamponade. At sacrifice (2 to 17 weeks), all other animals showed intact tricuspid valves with normal leaflet anatomy. All cultured biopsies generated myofibroblasts that were immunocytochemically positive for alpha smooth muscle actin, chondroitin sulfate, vimentin and fibronectin. CONCLUSION: Biopsy of the tricuspid valve to obtain recipient cardiac valve leaflet cells is possible, and the technique is simple and reliable. Biopsy of the leaflet does not compromise function. Interstitial cells can be harvested and expanded in culture. Cellular structure and function is preserved and is similar to that of other cardiac leaflet cells. Tricuspid valve leaflet biopsies are a potential source for harvesting cells to be used in the development of a tissue-engineered cardiac valve.