Effects of preceding endoscopic mucosal resection on the efficacy and safety of radiofrequency ablation for treatment of Barrett's esophagus: results from the United States Radiofrequency Ablation Registry

The effects of preceding endoscopic mucosal resection (EMR) on the efficacy and safety of radiofrequency ablation (RFA) for treatment of nodular Barrett's esophagus (BE) is poorly understood. Prior studies have been limited to case series from individual tertiary care centers. We report the results of a large, multicenter registry. We assessed the effects of preceding EMR on the efficacy and safety of RFA for nodular BE with advanced neoplasia (high-grade dysplasia or intramucosal carcinoma) using the US RFA Registry, a nationwide study of BE patients treated with RFA at 148 institutions. Safety outcomes included stricture, gastrointestinal bleeding, and hospitalization. Efficacy outcomes included complete eradication of intestinal metaplasia (CEIM), complete eradication of dysplasia (CED), and number of RFA treatments needed to achieve CEIM. Analyses comparing patients with EMR before RFA to patients undergoing RFA alone were performed with Student's t-test, Chi-square test, logistic regression, and Kaplan-Meier analysis. Four hundred six patients were treated with EMR before RFA for nodular BE, and 857 patients were treated with RFA only for non-nodular BE. The total complication rates were 8.4% in the EMR-before-RFA group and 7.2% in the RFA-only group (P = 0.48). Rates of stricture, bleeding, and hospitalization were not significantly different between patients treated with EMR before RFA and patients treated with RFA alone. CEIM was achieved in 84% of patients treated with EMR before RFA, and 84% of patients treated with RFA only (P = 0.96). CED was achieved in 94% and 92% of patients in EMR-before-RFA and RFA-only group, respectively (P = 0.17). Durability of eradication did not differ between the groups. EMR-before-RFA for nodular BE with advanced neoplasia is effective and safe. The preceding EMR neither diminished the efficacy nor increased complication rate of RFA treatment compared to patients with advanced neoplasia who had RFA with no preceding EMR. Preceding EMR is not associated with poorer outcomes in RFA.

Patterns of abnormal FDG uptake by various histological types of non-small cell lung cancer at initial staging by PET

The aim of this study was to identify useful patterns of abnormal fluorine-18 fluorodeoxyglucose (FDG) uptake by different types of non-small cell (NSC) lung cancer and to assess their clinical implications. One hundred and three sequential patients with newly diagnosed, pathology-proven NSC lung cancer were included. FDG positron emission tomography (PET) images were acquired using a dedicated PET scanner. There were 35 squamous cell carcinomas (SQC), 17 large cell cancers (LGC), 38 adenocarcinomas (ADC), 1 bronchioloalveolar carcinoma (BAC) and 12 non-classified NSC cancers. PET images were categorized into detectable patterns of necrotic center in the primary tumor, satellite lesions (T4), hilar lymph nodes (N1), and N2, N3, and M1 lesions by visual interpretation of PET images for SQC, LGC, and ADC (n=90; BAC and non-classified NSC cancers were excluded). The PET lesions were correlated with surgical pathology and with CT findings in inoperable cases. Necrosis was more commonly present in the primary tumors of LGC (53%) and SQC (43%) than in those of ADC (26%) (P<0.0001 and <0.01, respectively). The frequencies of nodal uptake in ADC, SQC and LGC were similar (71%, 60%, and 59%, respectively). However, M1 lesions were present significantly more often in LGC (41%) and ADC (34%) than in SQC (3%) (both P<0.0001). Significantly more surgically inoperable cases were found by PET (T4, N3, M1) in ADC (50%) and LGC (41%) than in SQC (26%) (P<0.001 and <0.02, respectively). Our results suggest a wide variation of PET findings for different types of NSC lung cancer. Identification of these patterns is useful in clinical PET interpretation, in that knowledge of the most probable association between the PET patterns and the histological types will facilitate initial staging and planning of management.

Incidence and significance of lobar atelectasis in thoracic surgical patients

Lobar atelectasis, defined by complete lobar collapse and mediastinal shift on chest roentgenogram, represents one extreme form of postoperative atelectasis. We have evaluated the incidence and clinical significance of lobar atelectasis in a thoracic surgical patient group. A retrospective review was done of patients who underwent pulmonary resection over a 2-year period to determine patient characteristics, contributing comorbidities, and associated perioperative care factors. Lung resections were performed for both benign and malignant disease through open or video-assisted techniques. One hundred eighty patients had pulmonary resection, 101 males and 79 females, and they were divided into three groups: I, no complications (112 patients, 62%); II, complications unrelated to lobar atelectasis (60 patients, 33%); and III, complications of lobar atelectasis (8 patients, 5%). There was one death in the series, in the lobar atelectasis group (III). Mean age for the entire group was 64.5 +/- 12.5 years; however, patients in Groups II (67.3 years) and III (69.6 years) were significantly older than in Group I (P < 0.02). Mean hospital length of stay in Group I was 6 +/- 3 days, whereas that in Group II was 13 +/- 12 days (P < 0.001), and in Group III it was 27 +/- 31 days (P < 0.001). In addition, patients who developed lobar atelectasis were more likely to be male (88% vs 48%, P = 0.034), had a longer ICU length of stay (P < 0.001), were more likely to have two or more comorbidities (P < 0.05), and had a lower forced expiratory volume in 1 second (2.34 +/- 0.90 vs 1.96 +/- 0.63). All patients in the lobar atelectasis group were operated on for malignancy, but this was not significantly different from the other groups. None of the 16 patients who had thoracoscopy developed lobar atelectasis, but this also was not a significant finding. We conclude that severe postoperative atelectasis occurs as lobar atelectasis in approximately 5 per cent of patients who undergo pulmonary resection and significantly adds to the intensive care unit and hospital length of stay. The etiology of lobar atelectasis appears to be multifactorial and warrants further study to define mechanisms of occurrence and their prevention.

Nonoperative management of gunshot wounds of the abdomen

Nonoperative management of stab wounds of the abdomen is currently practiced in many trauma centers; this report examines the role of expectant management of gunshot wounds to the abdomen in a select patient population. Patients presenting to a single trauma service from 5/91 to 1/94 at Detroit Receiving Hospital with a gunshot wound (GSW) to the abdomen fulfilling the following criteria were observed: 1) single GSW to the right upper quadrant, 2) stable vital signs, 3) reliable examination with minimal abdominal tenderness and available team/operating room, and 4) minimal or no abdominal tenderness. There were 12 patients fulfilling the study criteria; all were successfully observed. One nontherapeutic laparotomy was done due to abdominal tenderness. The role of expectant therapy of abdominal gunshot wounds is cautiously advanced. With appropriate criteria, this technique appears safe and efficacious.

Fibrin gel limits intra-abdominal adhesion formation

Autologous fibrin gel (FG) has recently been reported efficacious in hepatic injury; the effects of fibrin compounds on intra-abdominal adhesion formation is controversial. This study evaluated intra-abdominal adhesion formation in a rabbit devascularization model. Seventeen New Zealand rabbits were anesthetized and laparotomy was done. The uterine horns were abraded to punctate bleeding followed by bilateral uterine devascularization. Treatment consisted of 10 cc saline control (c) or FG applied to the uterine horns. Peritoneal lavage was done at 15 minutes for red blood cell (RBC) analysis. Autopsy was performed at 1 week. Adhesions were graded from grade 0 (no adhesions) to grade III (dense adhesions). Adhesion grading revealed no difference in average adhesion grade between FG and C with small bowel (1.0 +/- 1.3 vs 0.5 +/- 1.0); bladder (2.1 +/- 1.1 vs 2.4 +/- 1.2); or uterus (1.2 +/- vs 2.0 +/- 1.2). Adhesion grade was significantly less in FG compared to C for the colon and the abdominal incision (0.4 +/- 0.5 vs 1.7 +/- 1.1 and 1.2 +/- 1.1 vs 3.0 +/- 1.2; P less than 0.05 by t-test). There were no differences in lavage RBC count between FG and C (13.1 x 106 +/- 4.1 x 10(6) vs 8.7 x 106 +/- 3.2 x 10(6)). Fibrin gel significantly decreased incisional and colonic adhesions and reduced other abdominal adhesion formation by a nonhemostatic dependent mechanism.

A comparative study on in vitro invasion rates by melanoma cells in the human amniotic basement membrane model versus in vivo tumor nodule formation in C57BL6 mice

Invasion by murine B16-F10 melanoma cells was studied using the human amniotic basement membrane (HABM) assay. B16-F10 cells were collected after a single passage through the amnion and grown to near confluency. The cycle of plating, passaging, collecting, and culturing B16-F10 cells was repeated five times. The invasion rate for B16-F10 cells remained relatively unchanged after six passages through the amnion. Injection of first-passage B16-F10 cells into C57BL6 mice resulted in 29 lung tumors per animal whereas sixth-passage cells resulted in 300+ lung tumors. While there exists no correlation of the number of cells penetrating the amnion with colonization number, lung colonization appears correlated with increased number of passages through the amnion.