Endoscopic axillary exploration and sentinel lymphadenectomy.

BACKGROUND: Minimally invasive approaches have changed the practice of surgery in several specialties. The purpose of this study was to develop a reproducible endoscopic technique for the evaluation of the axilla in breast cancer patients. METHODS: A total of 23 patients with biopsy-proven breast carcinoma were enrolled. Patients were positioned in the supine position with the ipsilateral arm abducted at 90 degrees. A 1-cm skin incision was made at the superior aspect of the axilla. Dissection was carried bluntly to the lateral border of the pectoralis major. A balloon distention device was inserted into the tract and distended under endoscopic vision to create a working space. Insufflation was initiated up to a pressure of 8 mmHg. A 30 degrees laparoscope was introduced for visualization of axillary contents. One or two additional 5-mm cannulas were placed as needed under direct visualization. Manipulation of axillary contents was performed, and in 19 patients a sentinel node identification technique was applied. RESULTS: In all patients, using insufflation and minimal instrument dissection, the axillary vein, long thoracic, and thoracodorsal nerves were found in their usual anatomical locations. Utilizing blunt and sharp dissection, the axilla was thoroughly inspected, and individual lymph nodes were easily identified and extracted. In 11 of 19 patients, a sentinel node or blue dye was identified using isosulfan blue. There was a procedure concordance of 84%, and there were no complications. CONCLUSIONS: We describe a novel endoscopic technique for the evaluation of the axilla in breast cancer patients. This technique allows (a) creation of a minimally invasive working space within the axilla, (b) recognition of key axillary anatomic landmarks, and (c) instrument manipulation within the axilla to identify and extract lymph nodes, and apply the sentinel node technique. This is the first report of a minimally invasive approach to axillary exploration to employ sentinel lymph node mapping.

Comparison of acid reduction in antiulcer operations.

BACKGROUND: Three acid-reducing operations have recently been described for the laparoscopic treatment of peptic ulcer disease. These consist of a posterior truncal vagotomy combined with either (1) an anterior seromyotomy (SERO), (2) an anterior highly selective vagotomy (AHSV), or (3) a linear stapled lesser curvature excision (STAP). The purpose of this study was to investigate the physiologic effects of these procedures in terms of basal and maximal acid outputs. METHODS: Fifty New Zealand rabbits were prospectively randomized into five open laparotomy groups (n = 10): a control group without vagal manipulation (CON), a bilateral truncal vagotomy with pyloromyotomy group (VP), a SERO group, an AHSV group, and a STAP group. All animals underwent placement of a gastrostomy tube for subsequent gastric secretory analysis. On postoperative day 6, basal acid outputs (BAO) and maximal acid outputs (MAO) following IV pentagastrin stimulation (30 microg/kg/h) were measured. Results were compared statistically using the ANOVA method. RESULTS: Pentagastrin stimulation was associated with a significant increase in MAO in the CON group (p < 0.05 vs BAO); however, this response was effectively blunted in all the experimental groups. There were no differences in BAO or MAO between any of the vagotomized groups (SERO, HSV, STAP, VP). CONCLUSIONS: We conclude that the three acid-reducing procedures modified for laparoscopy are equally efficacious in reducing gastric acid secretion and that they compare favorably with VP. To our knowledge, this is the first report comparing basal and stimulated gastric acid secretion between these new acid-reducing techniques.

The protective effect of vein cuffed anastomoses is not mechanical in origin.

PURPOSE: Intimal hyperplasia (IH) is a proliferative process of vascular smooth muscle cells that occurs after an arterial injury, particularly at outflow anastomoses of prosthetic bypass grafts. IH causes stenosis that leads ultimately to graft flow reduction and thrombosis. We have demonstrated previously that vein cuff interposition between an expanded polytetrafluoroethylene (e-PTFE) graft and artery at distal anastomoses diminished IH formation in the arterial outflow as compared with noncuffed anastomoses. Improved long-term patency rates associated with the placement of an interposition vein cuff at the distal anastomosis of e-PTFE grafts to infrageniculate arteries have also been demonstrated clinically. This study examined the mechanical factors that may contribute to the protective effect of cuffed anastomoses. These factors include the expansibility of the vein cuff as compared with e-PTFE, as well as the angle of the cuffed anastomosis. METHODS: Compatible animals were selected by use of platelet aggregation studies. Nine dogs, group A, received a 4 mm e-PTFE graft plus a 1 cm long interposition vein cuff at the distal anastomosis in the left carotid artery. The same procedure was done on the right side, and in addition the vein cuff was encircled by an e-PTFE jacket incorporated into the anastomosis to prevent the expansion of the vein cuff with arterial pulsation. To study the effect of distal anastomotic angle and geometry on the formation of IH, five dogs, group B, received a 4 mm e-PTFE graft in both sides. On the left, the distal anastomosis was performed between the graft and the artery at an acute angle as it is commonly done when a bypass graft is placed. On the right side a 1 cm long, 6 mm diameter e-PTFE segment was interposed between the artery and the graft at a perpendicular angle. This geometry mimicked the right angle of a vein cuff-to-artery anastomosis. After 10 weeks the grafts were harvested, and the thickness of IH was measured with an ocular micrometer under light microscopy. RESULTS: In group A, one dog had bilateral graft thrombosis (12%), and these grafts were discarded. In the remaining eight dogs there was no statistically significant difference in the thickness of IH between the right (jacketed group) and the left side (nonjacketed/control group), showing that vein cuff expansibility did not play a role in protecting against the formation of IH. In group B, bilateral graft thrombosis occurred in four of five dogs (80%), suggesting that the perpendicular anastomotic angle was not protective. CONCLUSION: These results suggested that the protective effect of the vein cuff is not mechanical in origin.

Capsaicin-sensitive nerves mediate esophageal mucosal protection.

The esophageal mucosa is exposed to damaging agents both by ingestion and reflux. Using our in vivo rabbit model of esophagitis, we have observed that acute luminal exposure (within 1 to 5 minutes) to potentially harmful agents, such as acid, bile, or ethanol, induces a rapid increase in mucosal blood flow; whereas prolonged exposure (10 to 60 minutes) results in mucosal injury and ablation of blood flow. We have also shown that capsaicin-sensitive mucosal afferent nerves can modulate esophageal blood flow. These findings led us to hypothesize that the reactive increase in blood flow induced by luminal agents represents a mechanism of protection mediated by capsaicin-sensitive nerves. The objective of these experiments was to determine if luminal capsaicin, a specific probe for visceral afferent nerves, could both preserve mucosal blood flow and protect against ethanol injury. Rabbits were subjected to luminal instillation of 50% ethanol with or without 1% capsaicin. Blood flow was measured with microspheres at baseline and after 2 and 10 minutes. Rabbits exposed only to ethanol developed severe mucosal injury coincident with near ablation of mucosal blood flow. In contrast, rabbits exposed to ethanol with capsaicin showed protection of the epithelium with a sixfold increase in mucosal blood flow. We conclude that capsaicin-sensitive nerves in the esophagus are local effectors of mucosal protection by virtue of preserving blood flow.

Advantages of handsewn over stapled bowel anastomosis.

Bowel anastomoses are conventionally performed using a handsewn technique or a stapling device. Each has potential benefits and disadvantages. The most clinically significant complications of the bowel anastomosis are anastomotic leakage and stricture formation. The indices of healing and tissue cohesion were compared dynamically over time in 24 dogs randomized to undergo either a standard two-layer handsewn anastomosis or a stapled anastomosis with the Premium CEEA (United States Surgical Corporation, Norwalk, CT). Animals were sacrificed at 1, 4, 7, and 28 days postoperatively. Each anastomosis was evaluated for anastomotic index, burst pressure, collagen content, and histologic appearance. The anastomotic index was similar on postoperative day (POD) 1, 4, and 7; but on day 28 all handsewn anastomoses had larger diameters than the widest CEEA anastomosis. Burst pressure was higher in handsewn anastomoses at all intervals. Collagen content tended to be higher on POD 7 in the CEEA anastomoses. Histological evaluation showed more complete epithelialization and less inflammation in handsewn anastomoses on POD 28. The higher level of collagen in the CEEA anastomoses on POD 7 may be implicated in the tendency toward stricture formation found with this type of anastomosis. This study demonstrates that the greater speed and ease of the stapled anastomosis is offset by the greater strength, reduced tendency to stricture, and more complete healing of the handsewn anastomosis.