Empyema following percutaneous catheter drainage of upper abdominal abscess.

Percutaneous catheter drainage is a standard therapy for management of selected intra-abdominal abscesses. We describe three patients in whom this technique caused complicated thoracic empyemas. All patients required thoracotomy for decortication despite initial thoracostomy tube drainage. In each case, the percutaneously placed drainage catheter was found traversing the costophrenic angle, leading to direct communication between the pleural space and the abscess cavity. Review of the anatomic relationships of the inferior pleural margin to the lower ribs may help prevent this technical error.

The thoracic vent. Clinical experience with a new device for treating simple pneumothorax.

We report recent experience with a new device, the thoracic vent, in the management of simple pneumothorax. There were 16 patients aged 19 to 73 years who suffered pneumothorax due to spontaneous (4), traumatic (3), or iatrogenic (9) causes. Ease of insertion, patient tolerance, and the presence of a unique signal diaphragm all contributed to patient and physician acceptance of the device. Average time to pneumothorax resolution was 2.5 days, and time to thoracic vent removal averaged 3.2 days. There were no immediate recurrences or significant complications. We conclude that the thoracic vent is an effective device for initial and definitive therapy of simple pneumothorax.

The interaction of retrovirus and chemical carcinogen in experimental colon carcinogenesis.

The isolation and characterization of oncogenes from human colon cancer and the recognition of their homology with the ras gene of the Harvey and Kirsten strain of murine sarcoma virus (MSV) led us to investigate the effect of exogenous MSV on 1,2 dimethylhydrazine (DMH)-induced colon carcinoma in rats. DMH, 20 mg base/kg, was injected weekly for 10 weeks into Sprague-Dawley rats. The Moloney murine sarcoma virus (MSV-M) was injected (200 focus-forming units) intraperitoneally into 15 rats 48 hours after the last DMH injection or in 12 rats before the first DMH injection. Controls consisted of 12 rats receiving 10 injections of DMH only, nine rats receiving MSV-M alone, and 10 untreated rats. All tumors induced were adenocarcinomas of the gastrointestinal tract, characteristically induced by DMH and not by MSV-M. In the late virus group there was an augmentation of colon tumor induction (mean, 2.2 versus 1.1 colon tumors/rat, p less than 0.05), and in the MSV pretreated group, there was also significant augmentation of colon tumor induction (mean, 2.4 versus 1.1 colon tumors/rat, p less than 0.005) when compared with rats treated with DMH alone. Rats treated with MSV-M alone and untreated rats had no tumors. This is the first study to suggest the importance of exogenous viral infection in chemically induced colonic carcinogenesis.

Management of perforated appendicitis in children--revisited.

Of 522 children with acute appendicitis treated from 1978 to 1985, 170 had appendiceal perforation with peritonitis. The protocol for perforation included aggressive fluid resuscitation, preoperative triple antibiotic therapy, copious peritoneal lavage, avoidance of transperitoneal drains except those used for well-localized abscesses, delayed wound closure, and postoperative antibiotic therapy for seven to ten days. The minor complication rate was 22%; this included pleural effusion, wound infection, atelectasis, and prolonged ileus. The major complication rate was 3%; this included intra-abdominal abscess, gastrointestinal bleeding, wound dehiscence, pneumonia, and intestinal obstruction. Only four postoperative intra-abdominal abscesses occurred, in three patients. The mortality rate was zero. A comparison of this series with a similar group of 24 patients who underwent drainage showed the relative rate of abdominal abscess formation to be 1.8% (undrained) vs 12.5% (drained). We achieved our lowest rate of serious complications following surgery for pediatric perforated appendix with the use of aggressive fluid resuscitation, broad-spectrum antibiotic therapy, copious peritoneal irrigation, and delayed wound closure and without drainage.

Inability of the mutagen-blocking agent oleic acid to protect against colon carcinogenesis in the rat.

Oleic acid has been found in cooked beef and human feces. It has also been found to protect against mutagenesis as measured by the Salmonella microsomal assay test. Addition of oleic acid to the diet of rats treated with 1,2-dimethylhydrazine, a colon carcinogen, failed to protect the rats against the induction of colon cancer.

Protective role of faecal pH in experimental colon carcinogenesis.

There is epidemiological evidence that populations with alkaline stool pH are at greater risk for colon cancer than populations with acid stool pH. This association was investigated in the laboratory using the rat-dimethylhydrazine colon carcinogenesis model. Rats with acid stool pH, produced by consumption of lactulose or sodium sulphate or both, had significantly fewer colon tumours after injections of dimethylhydrazine (DMH) than rats treated with DMH alone. The results confirm the hypothesis that acidification of the stool can protect against the induction of colon cancer.

Neither dietary ethanol nor beer augments experimental colon carcinogenesis in rats.

There is an epidemiologic association between beer consumption and rectal cancer. Beer and ethanol were tested in the rat-dimethylhydrazine (DMH) experimental carcinogenesis model in order to verify this observation. Ethanol was found not to affect the number of colonic tumors induced by DMH (86 vs. 77 controls, P = 0.764). In rats fed beer and treated with DMH, there was a decrease in gastrointestinal tumor induction (P = 0.043). This instance then becomes one of many in which conclusions drawn from epidemiologic studies have been contradicted when subjected to analysis in an experimental colon carcinogenesis model.

A new method of rapid fluid resuscitation during thoracotomy performed in the emergency room.

A new technique for inserting and securing large bore intravenous lines directly into the right atrium, to be used in patients requiring a thoracotomy in the emergency room, is described herein. A plastic clip is attached to the edge of the atrial appendage and holds a large catheter in place. We have used this new technique successfully at the Cook County Hospital Trauma Unit and have encountered no complications to date.

A new concept in the surgical treatment of gastroesophageal reflux.

Surgical treatment of gastroesophageal reflux has been thought to depend on the construction of a valve mechanism at the gastroesophageal junction (GEJ). Recently, a silicone prosthesis that does not construct a valve has been introduced, and in preliminary studies in the human, shown to be effective in the treatment of reflux. A precise mode of action has not been demonstrated for the prosthesis. This study was undertaken to investigate the mechanics of the prosthesis and determine its effectiveness in an animal model. Six canine gastroesophageal specimens were excised and the lower esophageal sphincter (LES) simulated by a rubber band placed around the GEJ at a tension calibrated to give 25 mmHg "sphincter" pressure. Circumferential silk ligatures of varying length were then placed on the stomach 3.0 cm distal to the GEJ. With no ligature, the LES opening pressure (LESOP) was 8.0 mmHg, varying to 17.0 mmHg with an 8.0 cm ligature. Further, 24 adult mongrel dogs were randomly divided into four equal groups: controls, circular myomectomy of the LES alone, myomectomy combined with fundoplication, and myomectomy combined with implantation of the silicone antireflux prosthesis. Evaluation included manometry, endoscopy, and histology. Although only the normal sphincter and fundoplication responded physiologically, the prosthesis was just as effective in preventing reflux, as evidenced by reducing acid exposure time of myomectomized dogs from 35.4% to 1.8%, and by preventing endoscopic esophagitis. It was concluded that the silicone antireflux prosthesis acts in the same fashion as the ligature in the model, by interrupting distraction of the LES by gastric wall tension. This concept is an effective method for raising LESOP, treating experimental gastroesophageal reflux, and eliminating the sequelae of reflux. Long-term evaluations of the prosthesis are required.