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E Christopher Ellison

Publications and source records attributed to E Christopher Ellison.

26 records · Page 2Linked to original sources
PubMed2003

Laparoscopic parastomal hernia repair.

Parastomal hernia is a common complication of ostomy construction. The morbidity and recurrence rates associated with repair can be quite high. Among the various approaches to repair, the lowest recurrence rates are associated with the use of mesh. We report a case in which a parastomal hernia was repaired laparoscopically. By employing this minimally invasive approach, our patient avoided the morbidity associated with laparotomy for intraperitoneal mesh placement.

Aged↗
PubMed2002

Oxidant-induced vascular endothelial growth factor expression in human keratinocytes and cutaneous wound healing.

Neutrophils and macrophages, recruited to the wound site, release reactive oxygen species by respiratory burst. It is commonly understood that oxidants serve mainly to kill bacteria and prevent wound infection. We tested the hypothesis that oxidants generated at the wound site promote dermal wound repair. We observed that H(2)O(2) potently induces vascular endothelial growth factor (VEGF) expression in human keratinocytes. Deletion mutant studies with a VEGF promoter construct revealed that a GC-rich sequence from bp -194 to -50 of the VEGF promoter is responsible for the H(2)O(2) response. It was established that at microm concentrations oxidant induces VEGF expression and that oxidant-induced VEGF expression is independent of hypoxia-inducible factor (HIF)-1 and dependent on Sp1 activation. To test the effect of NADPH oxidase-generated reactive oxygen species on wound healing in vivo, Rac1 gene transfer was performed to dermal excisional wounds left to heal by secondary intention. Rac1 gene transfer accelerated wound contraction and closure. Rac1 overexpression was associated with higher VEGF expression both in vivo as well in human keratinocytes. Interestingly, Rac1 gene therapy was associated with a more well defined hyperproliferative epithelial region, higher cell density, enhanced deposition of connective tissue, and improved histological architecture. Overall, the histological data indicated that Rac1 might be an important stimulator of various aspects of the repair process, eventually enhancing the wound-healing process as a whole. Taken together, the results of this study indicate that wound healing is subject to redox control.

Animals↗
PubMed2002

Evolution of minimally invasive bariatric surgery.

BACKGROUND: Minimally invasive Roux-en-Y gastric bypass is a procedure that is being performed with increasing frequency. It is an advanced laparoscopic procedure with a steep learning curve. With experience, it can be performed in a reasonable amount of time with minimal morbidity. METHODS: We first performed minimally invasive gastric bypass with the hand-assisted laparoscopic surgery (HALS) technique. After significant experience with HALS, we changed our approach to completely laparoscopic (LS). Our technique for all cases involves a circular stapled gastrojejunostomy with a 25-mm anvil passed transgastrically. RESULTS: From June 1998 to January 2002, 304 patients underwent minimally invasive gastric bypass. Our first 81 cases were with HALS, and the rest were LS. The incidence of early major and minor perioperative complications for the entire series was 5.6% and 7.9%, respectively. Early reoperation (less than 30 days) was required in 4.6% of all patients. There was 1 leak (1.2%) in the HALS group and 4 anastomotic leaks (1.8%) in the LS group. Other measured outcomes were similar in each group with the exception of wound hernia (16% HALS vs 0.9% LS). Weight loss after 1 year was 44% for HALS and 56% for LS. We have not had any deaths in our series. CONCLUSIONS: HALS may have certain advantages in selected patients and early in a surgeon's experience with minimally invasive gastric bypass. With experience, good results are possible with either approach.

Adult↗
PubMed2002

Copper-induced vascular endothelial growth factor expression and wound healing.

Angiogenesis plays a central role in wound healing. Among many known growth factors, vascular endothelial growth factor (VEGF) is believed to be the most prevalent, efficacious, and long-term signal that is known to stimulate angiogenesis in wounds. Whereas a direct role of copper to facilitate angiogenesis has been evident two decades ago, the specific targets of copper action remained unclear. This report presents first evidence showing that inducible VEGF expression is sensitive to copper and that the angiogenic potential of copper may be harnessed to accelerate dermal wound contraction and closure. At physiologically relevant concentrations, copper sulfate induced VEGF expression in primary as well as transformed human keratinocytes. Copper shared some of the pathways utilized by hypoxia to regulate VEGF expression. Topical copper sulfate accelerated closure of excisional murine dermal wound allowed to heal by secondary intention. Copper-sensitive pathways regulate key mediators of wound healing such as angiogenesis and extracellular matrix remodeling. Copper-based therapeutics represents a feasible approach to promote dermal wound healing.

Animals↗
PubMed2002

Frozen section diagnosis of pancreatic lesions.

BACKGROUND: The clinical and radiologic diagnosis of pancreatic cancer and the safety of pancreatic resections have improved. These improvements, together with the indication for resection in some cases of complicated chronic pancreatitis, have reduced the necessity for confirmed preoperative tissue diagnosis. We investigated the clinical use and accuracy of frozen section diagnosis for pancreatic lesions. DESIGN: We searched archival files for the years 1989-2000 for patients with pancreatic lesions who had received a diagnosis based on frozen section results. We compared the diagnosis of all frozen section slides with that of the permanent sections and reviewed the clinical follow-up notes. We evaluated histologic features useful in differentiating between malignant and benign pancreatic lesions. RESULTS: A total of 538 patients underwent surgical biopsy and/or resection for suspected pancreatic lesions. Frozen section was requested in 131 cases (284 frozen sections). Ninety cases had frozen section of the pancreatic lesions, 70 cases had frozen section of metastatic sites, and 29 cases had frozen section of surgical margins. Of the 90 cases in which frozen section of the pancreatic lesions was requested, malignancy was diagnosed in 44, a benign lesion was diagnosed in 37, and the diagnosis was atypical and deferred in 9. In total, 3 false-negative frozen sections and 1 false-positive frozen section were identified for respective rates of 1.2% and 0.3%. In all cases in which the frozen section diagnosis was deferred or was inconsistent with the operative impression, and the surgeon acted on his/her impression, the operative diagnoses were subsequently confirmed by additional permanent sections and/or clinical follow-up. The most useful histologic features for the diagnosis of pancreatic adenocarcinoma in frozen sections were variation in nuclear size of at least 4:1, disorganized duct distribution, incomplete duct lumen, and infiltrating single cells. CONCLUSIONS: Frozen sections are useful in conjunction with the impression at surgery for the management of patients with pancreatic lesions. Frozen sections of resection margins were 100% accurate; frozen sections of pancreatic lesions or metastatic sites were accurate in 98.3% of cases. We found an acceptable rate of deferred frozen section (6.6%). The experienced surgeon's impression of malignancy is reliable in cases in which frozen section is deferred or has negative findings.

Adenocarcinoma↗
PubMedDate not supplied

Computer-enhanced vs. standard laparoscopic antireflux surgery.

Computer-assisted telesurgical devices have recently been approved in the United States for general surgery. To determine the safety and efficacy of these procedures, we performed a prospective trial of computer-enhanced "robotic" fundoplication compared to standard laparoscopic control procedures. Consecutive patients undergoing surgical treatment for gastroesophageal reflux were included. The operating surgeon worked at a console using a three-dimensional image and manipulated hand controls. Operative times, complications, and length of hospital stay were recorded. A standardized questionnaire was administered to evaluate symptoms. Twenty patients were entered into each group. There were no differences in age, preoperative weight, or sex. Operative times were significantly longer in the robot group (97 vs. 141 minutes). There were no complications and most patients went home the first postoperative day. At follow-up, symptoms were similar in both groups; however, there was a significant difference in the number of patients taking antisecretory medication--none in the robotic group but six in the laparoscopic group reported regular use. Computer-assisted laparoscopic antireflux surgery is safe. However, operative times are longer, with little difference in outcomes. At the current level of technology and experience, robotic antireflux surgery appears to offer little advantage over standard laparoscopic approaches.

Adult↗