Biomedical subjects
Publications and source records attributed to W D Harrison.
Pneumoperitoneum results from perforation of the gastrointestinal tract in the majority of instances and the necessity of operative treatment is implied. In patients where peritonitis is not a problem, nonoperative treatment is successful. Surgical treatment is not required for those in whom the condition results from barotrauma. The decision to enjoin or withhold operative intervention in individual cases is judgmental.
Apudomas are a diffuse group of tumors that have interested surgeons for a long time. With recent developments in their radiological localization and pharmacological control, they are now treated in a truly multidisciplinary approach. In this chapter, recent developments in the radiological, surgical, and medical approaches to these tumors are reviewed. Emphasis is placed on how non-surgical developments have affected the surgical treatment of specific apudomas. Resulting changes in surgical philosophy are also reviewed.
Transient delayed gastric emptying is reported as a frequent complication following pancreas-preserving pancreaticoduodenectomy (PPW). We placed serosal electrodes on the stomach of a patient undergoing PPW. Myoelectric recordings were obtained postoperatively and correlated with simultaneous radionuclide liquid gastric emptying studies. The patient developed early postoperative gastric atony, associated with frequent gastric dysrhythmias. These dysrhythmias may have been exacerbated by a perihepatic abscess. The gastric dysrhythmias correlated with alterations in liquid gastric emptying. Gastric dysrhythmias may be a mechanism for gastric dysfunction in the early postoperative period.
The purpose of this study was to compare gastric emptying and Roux myoelectric activity in a canine model. Four dogs underwent truncal vagotomy, antrectomy, and 40 cm Roux-en-Y gastrojejunostomy, with placement of serosal electrodes. Following recovery, gastric emptying was determined scintigraphically with a radiolabeled solid meal, and fasting and fed small-bowel myoelectric activity was obtained. Gastric emptying was markedly slowed compared to control unoperated animals (202 +/- 91 versus 46 +/- 12 min; P less than 0.05). Slow wave frequency declined in the Roux limb compared to the duodenum (14.2 +/- 0.4 versus 18.0 +/- .06 counts per minute; P less than 0.01). No gradient in slow wave frequency was observed in the Roux limb, although one animal was noted to have reversed propagation of slow waves in the proximal Roux limb. Migrating myoelectric complexes (MMCs) were coordinated between the Roux limb and jejunum distal to the enteroenterostomy, but not with the duodenum. Periodicity of the MMCs was different in the Roux limb and duodenum (98.6 +/- 6.3 versus 138 +/- 17.5 min; P less than 0.05). None of the animals converted to the fed myoelectric pattern with a 272 kcal meal (MMC periodicity in the Roux limb = 99 +/- 10 min postprandially, P = N.S.). These quantitative and qualitative alterations in myoelectric activity may contribute to the observed delay in gastric emptying following Roux-en-Y gastrojejunostomy.
Braun enteroenterostomy with stapled occlusion of the afferent limb has been advocated to treat bile gastritis and to avoid the motility effects of Roux-en-Y gastrojejunostomy. However, the motility effects of stapled occlusion are unknown. Myoelectric activity and histologic features were studied after stapled occlusion of the small bowel in a canine model. A 35 cm "recirculating loop" was created with a side-to-side anastomosis, beginning 25 cm from the ligament of Treitz. Serosal electrodes were placed at 5 cm intervals on the loop; at a second operation in one dog and simultaneously in three dogs, the bowel was occluded midway between two electrodes with 4.8 mm staples. Fasting recordings were obtained at weekly intervals to 6 months after surgery and were analyzed for slow wave frequency proximal and distal to the staple line and for propagation time of phase 3 of the migrating myoelectric complex across the staple line. The side-to-side anastomosis did not alter myoelectric activity. However, after stapled occlusion of the small bowel, the slow wave frequency dropped from a mean of 18.2 +/- 0.4 cpm proximally to 15.4 +/- 1.0 cpm distally (p less than 0.05). This correlated with loss of myogenic continuity in three of four animals. Propagation of phase 3 slowed across the staple line (115 +/- 27 seconds versus 47 +/- 9 seconds) (p less than 0.02). The bowel lumen recannulated in all animals. Stapling across the small bowel alters myoelectric activity, and occlusion of the bowel lumen may not be permanent.
In 27 closed chest dogs left ventricular wall motion abnormalities assessed quantitatively with two dimensional echocardiography were used as a measure of myocardial infarct size, and the change in extent of segmental wall motion abnormalities due to drug intervention early after infarction was evaluated. The extent of wall motion abnormalities was measured with echocardiography before and at 20 and 40 minutes and 5 1/2 hours after coronary occlusion. Three subgroups of dogs received, respectively, an infusion of nitroglycerin, phenylephrine or saline solution. Infarct size was measured with technetium pyrophosphate scintigraphy of the excised left ventricle. The infarct size correlated well with the extent of wall motion abnormalities before death. Wall motion was initially similar among the three groups but was significantly improved after treatment with nitroglycerin (P less than 0.025), remained stable with continued saline infusion and worsened significantly (P less than 0.05) after treatment with phenylephrine. Two dimensional echocardiography can be used to quantify experimental canine myocardial infarction and assess the effect of nitroglycerin.