[Acute carpal tunnel syndrome in a patient with Marfan syndrome]

Acute carpal tunnel syndrome (ACTS) is rare and is mostly the result of fractures of the distal radius or the carpal bones. This paper gives the first report of an ACTS following contusion of the wrist as the result of an extensive haematoma of the flexor tendon sheath, which did not appear until 50 hours after the injury was sustained but then developed rapidly. The patient suffers from Marfan syndrome. This disease is associated with pathologic changes to the major vessels, and especially the aorta, and of the smaller peripheral vessels. It is assumed that the haematoma arose from an aneurysm of such a small vessel. The treatment of choice in ACTS is emergency incision of the carpal tunnel.

[Dissection technique--is ultrasound the best method?]

Preventive hemostasis is extremely important in endoscopic surgery. Ultrasonic dissectors are used very often. We tested the occlusion safety of bipolar forceps and ultrasonic dissector for porcine vessels. Thermographic videos showed maximum temperature up to 200 degrees C when using one ultrasonic dissector. The lateral damage zone in vivo and in vitro measured between 2 and 6 mm.

Functional results after laparoscopic rectopexy for rectal prolapse

We investigated the functional results after laparoscopic rectopexy for rectal prolapse in 29 patients at least 12 months postoperatively. Twenty patients were evaluated completely pre- and postoperatively (median 22 months postoperatively, range 12 to 54 months). Six patients were interviewed by telephone, two patients were lost to follow-up, and one patient died of causes unrelated to rectal prolapse. Patients underwent a proctologic examination, anoscopy, rigid sigmoidoscopy, fluoroscopic defecography, and anorectal manometry pre- and postoperatively, and an additional standardized interview postoperatively. Anorectal manometry showed a significant increase in maximum anal resting and squeeze pressures postoperatively (resting pressure 72 +/- 8 vs. 95 +/- 13 mm Hg, pre- vs. postoperatively; P = 0.046; squeeze pressure 105 +/- 17 vs. 142 +/- 19 mm Hg, pre- vs. postoperatively; P = 0.035), and continence improved postoperatively (Wexner incontinence score 6.0 +/- 1.0 vs. 3.9 +/- 0.8 pre- vs. postoperatively, P = 0.02). Twenty (77%) of 26 patients were satisfied with the operative result, but functional morbidity was observed in four patients, with two patients complaining of severe evacuation problems. Rectal prolapse recurred in one patient 42 months postoperatively (recurrence rate 1 [3.8%] of 26 patients). Functional results were very similar to those obtained after open rectopexy, with symptoms of prolapse and incontinence improved in the great majority of patients.

[Differential achalasia therapy]

The early relief of esophageal outflow obstruction in patient with achalasia diminishes complaints and avoids deterioration as a result of this disease. The pneumatic myotomy of the lower esophageal sphincter is the initial therapeutic concept. After two unsuccessful dilations, the laparoscopic myotomy with semifundoplication shows the best long-term results in the treatment of achalasia with fewer complications.

[Achalasia: botulinus toxin, interventional balloon dilatation, myotomy?]

67 patients with achalasia were treated either medically, endoscopically or surgically from 1987 to 1997 in the Department of Surgery of the University of Tübingen. 27/67 (40%) of the patients, who were pneumatically dilatated, had a very successful therapy within the first year after dilatations. 12/67 (17%) of the patients had good results with a dysphagia score less than 1 after dilatations within the first year. The perforation rate of interventionally treated patients was 1.4% without any surgical procedure. Open myotomy according to Heller was performed in 28 of 67 patients (41%); after 1993 a laparoscopic procedure was performed in all patients. The average hospitalization for MIC was 5.4 days. The manometric control investigations showed a decrease of the basal LES pressure from preoperative values. When evaluated manometrically 87% showed good results in the follow up time of at least 24 months. 14% of those who underwent surgery had to be endoscopically dilatated after surgery.

Indications and results of local treatment of rectal cancer

BACKGROUND

Local therapy of early rectal carcinoma has become an alternative to the classical radical operation which has a higher morbidity and mortality rate.

METHODS

Rectal carcinoma was treated by transanal endoscopic microsurgery (TEM) in 113 patients. The indications for the procedure were pT1 low-risk tumour, advanced tumour in high-risk patients, and patients who refused more radical surgery based on oncological guidelines.

RESULTS

Sixty-four patients had pT1, 33 pT2 and 16 pT3 tumours. No patient died as a result of TEM. The rate of complications which needed operative intervention was 7 per cent. So far, two of the patients treated by local resection of pT1 low-risk tumours have had a recurrence. In both cases, a secondary procedure was possible with curative intent.

CONCLUSION

Patients with pT1 rectal tumours represent a suitable group for local treatment because of the acceptability of the procedure and the low recurrence rate.

Indications and results of local treatment of rectal cancer

BACKGROUND

Local therapy of early rectal carcinoma has become an alternative to the classical radical operation which has a higher morbidity and mortality rate.

METHODS

Rectal carcinoma was treated by transanal endoscopic microsurgery (TEM) in 113 patients. The indications for the procedure were pT1 low-risk tumour, advanced tumour in high-risk patients, and patients who refused more radical surgery based on oncological guidelines.

RESULTS

Sixty-four patients had pT1, 33 pT2 and 16 pT3 tumours. No patient died as a result of TEM. The rate of complications which needed operative intervention was 7 per cent. So far, two of the patients treated by local resection of pT1 low-risk tumours have had a recurrence. In both cases, a secondary procedure was possible with curative intent.

CONCLUSION

Patients with pT1 rectal tumours represent a suitable group for local treatment because of the acceptability of the procedure and the low recurrence rate.

Endoscopic microsurgical dissection of the esophagus (EMDE)

This paper presents endoscopic microsurgical dissection of the esophagus (EMDE), a surgical technique for the therapy of esophageal cancer which improves blunt esophageal dissection with the aim of reducing postoperative morbidity and mortality. A mediastinoscope with integrated operative instrument channel, fibre bundles, optic and rinsing channel has been developed whereby precise and atraumatic esophageal dissection is possible via a cervical access incision. Between 1989 and 1993, 37 patients were operated on using the EMDE technique and are compared with 48 patients operated on during the same period by the thoraco-abdominal route. The operative duration was reduced by the new technique, and although the number of severe complications was not significantly different between both groups, the rate of pulmonary and cardiac complications was reduced. The mortality rate was 10% for EMDE patients and 14% for the thoraco-abdominal procedure, and there was no difference in the long-term survival rate. As distinct from procedures requiring a thoracotomy for esophageal dissection, EMDE permits ventilation of both lungs throughout the entire operation and reduces the total operative trauma.

Functional results after transanal endoscopic microsurgery

PURPOSE

Compared with traditional operations, superior results after transanal endoscopic microsurgery (TEM) for rectal tumors have been demonstrated in terms of morbidity and mortality. However, no data were available on functional outcome after TEM. We, therefore, studied 42 patients who were undergoing TEM.

METHODS

Patients were examined by anorectal manometry and participated in a standardized interview preoperatively and three months and one year after surgery.

RESULTS

Anorectal function as assessed by manometry was impaired three months after surgery but improved again during the first postoperative year. In parallel, some patients complained of impaired continence or defecation disorders in the interview three months postoperatively. These functions improved during the first year after surgery, too.

CONCLUSIONS

Correct comparison of our results with functional outcome after anterior rectal resection is impossible. We feel, however, that functional results after TEM are likely to be superior to those after anterior resection for rectal tumors.

Local therapy of rectal tumors

PURPOSE

The aim of the study is to outline the rising importance of local treatment of rectal tumors and a changing strategy in therapy of early rectal cancer.

METHODS

As the surgical procedure, transanal endoscopic microsurgery was used. Indications for the local procedure were pT1 low-risk tumors and tumors of higher stages in patients with severe risk factors and of those who refused the operation according to oncologic guidelines.

RESULTS

A total of 236 rectal adenomas and 98 carcinomas were locally excised using the transanal endoscopic microsurgery technique. Mortality rate was 0.3 percent, and rate of complications requiring surgical reintervention was 5.5 percent in adenomas and 8 percent in carcinomas. Final histology of removed carcinomas revealed 56 pT1, 27 pT2, and 15 pT3 stages. After an average follow-up time of 24 months, two recurrences were observed in the group of patients with pT1 low-risk carcinomas who only underwent local therapy. In both cases, a second intervention for cure was undertaken but for tumors in a late stage.

CONCLUSIONS

In selected cases, local therapy of rectal carcinoma avoids high morbidity and mortality of the classical operation. Quality of life will be improved, especially if an artificial anus can be avoided. In case of recurrence, the chance of a secondary procedure for cure is not to be underestimated.

Sulbactam in combination with mezlocillin, piperacillin or cefotaxime: clinical and bacteriological findings in the treatment of serious bacterial infections

An open, multicentre study was performed in hospital in-patients at a total of 12 German hospitals to investigate the efficacy and tolerability of sulbactam combined with mezlocillin, piperacillin or cefotaxime in severe bacterial infections. A total of 155 patients were recruited into the study, of whom 48 were suffering from respiratory tract infections, 66 from intra-abdominal infections, 34 from skin/soft tissue infections including postoperative wound infections, and five from complicated urinary tract infections. Fifty-five patients intravenously received 4 g mezlocillin and 1 g sulbactam three times daily, 52 received 4 g piperacillin and 1 g sulbactam three times daily, and 48 received 2 g cefotaxime and 1 g sulbactam three times daily. The antibiotic and sulbactam combination was administered in all cases by rapid intravenous infusion of both components together, over 20 min. The mean duration of treatment was 20 days. The criteria used to define the outcome of treatment as successful were clinical cure (complete disappearance of the signs and symptoms of infection seen before the start of treatment) or improvement (appreciable diminution or partial resolution of the initial signs and symptoms, no further antibiotic therapy required) and the elimination of the organisms isolated before the start of the study. Of the 153 clinically evaluable patient, 141 (92%) were classed as responders (a cure was obtained in 98 cases and improvement in 43 cases). No response to the study medication was seen in 12 patients (7.8%). The response rates of the combined antibiotic-sulbactam preparations were 91% for mezlocillin/sulbactam, 92% for piperacillin/sulbactam, and 93% for cefotaxime/sulbactam. These response rates are almost identical. A total of 106 patients (68.4%) were bacteriologically evaluable; a total of 192 bacterial organisms were identified in these patients before the start of treatment. Mixed infection was present in 55 patients. The causative organism initially isolated was eliminated in 96 patients (90%), accounting for 180 of 192 strains (94%). Persistence of the causative organism (12 strains) was seen in eight patients (7.6%). Superinfection (four strains) was seen in two patients (1.9%). The study medication was well tolerated; adverse drug effects were seen in only five patients (3.3%). Treatment was discontinued in one patient because of the adverse effect (exanthema). The combination of the beta-lactamase inhibitor sulbactam and a ureidopenicillin or cefotaxime was highly effiacious in patients with severe bacterial infections investigated in this study. The availability of sulbactam as a single-agent preparation opens up new avenues for flexible and cost-effective antibiotic therapy and is a valuable contribution to the control of bacterial resistance.

[Local therapy of rectum carcinoma. A prospective follow-up study]

Local therapy of rectal carcinoma with the method of TEM was performed in 98 patients during the period from August 1, 1989 to January 31, 1994. 56 of the patients had pT1, 27 pT2, and 15 pT3 tumours. There was no lethality. The rate of complications, which required operative intervention, was 8%. No lymph node metastases were found in the specimens of the patients with pT1 tumours, who were re-resected, because the margin of the primary specimen were judged to be not free of tumour. In the specimens of the re-resected patients with pT2 carcinomas, lymph node involvement was more common than remnants of the primary tumour. Two of the patients with local therapy of pT1 low-risk carcinomas developed a recurrence so far. A secondary procedure for cure according to oncologic criteria could be performed in both cases. In selected cases the local therapy of rectal carcinoma avoids the high morbidity and mortality of the classical operation. Live quality will be improved, especially if an artificial anus can be avoided. In case of a recurrence the chance of a secondary procedure for cure is not to be underestimated.

[Follow-up results of laparoscopic cholecystectomy]

Following a laparoscopic cholecystectomy 400 patients have been interviewed with a questionnaire on the late results of the surgery (15 to 40 months postop.). The cholecystectomies had been performed within the time from March 7, 1990 to April 30, 1992 in Tübingen. After a mean of 16.8 days the patients returned to work, while they themselves felt reduced for an average of 10.6 days. 11.9% of the patients complained of slight wound healing problems and in 3.1% wound infections have been registered. Although 97% of the patients were satisfied with the results of surgery, 8.7% still complained of upper abdominal trouble. Slight persistent problems like light pain or flatulence have been reported by 19%.

TEM results of the Tuebingen group

From August 1st 1989 to May 1st 1993, 190 rectal adenomas and 75 carcinomas were locally excised with the TEM technique. The mortality was 0.4%, the rate of complications which required surgical re-intervention was 3% in adenomas and 8% in carcinomas. The final histology of the removed carcinomas revealed 44 pT1, 23 pT2 and eight pT3 stages. In two of the eight re-resected patients with pT1 low-risk tumours, residual primary tumour but no lymph node metastases were found. In contrast to this, three of the eleven re-resected patients with pT2 low-risk tumours had already developed lymph node metastases. After an average follow-up time of 14 months, two recurrences were observed in the group of the only locally treated patients with pT1 low-risk carcinomas. Both underwent a secondary procedure for cure but in late tumour stages. No recurrence was diagnosed so far among the re-resected patients.

Indications and technique for TEM (transanal endoscopic microsurgery)

Transanal Endoscopic Microsurgery (TEM) was introduced into clinical practice by the Buess group in 1983. Since then vast experience has been gained in removing tumours of the rectum by the operative rectoscope. Though the indication in benign lesions for TEM as a local resection therapy is undisputed, the indication for resection of T1 or advanced carcinomas has to be evaluated. By using a 40 mm operating rectoscope sealed with a gastight working insert to prevent pressure loss after creation of a pneumorectum and a stereoscopic optic with sixfold magnification, exact visualisation of a rectal tumour can be achieved. The insertion of endoscopic surgical instruments like the high frequency knife, forceps, scissors, and suction device allows precise excision of the lesion as well as suture closure of the wound. Recently a bipolar multifunctional combination instrument has been developed for more precise dissection, less blood loss and shorter operation times.

Technique of endoscopic mediastinal dissection of the oesophagus

Conventional transhiatal dissection of the oesophagus is usually performed without visual control. The attendant danger of this is that complications such as bleeding and tracheal lesions may be overlooked. This problem can be avoided by the use of an endoscopic operation system. This report describes a new technique of endoscopic microsurgical dissection of the oesophagus (EMDOE) and the results of the first 35 cases. Under visual control with a specially designed mediastinoscope the soft tissue surrounding the oesophagus is carefully dissected, and the oesophageal blood vessels can be safely exposed, coagulated and divided. The dissection begins cervically and proceeds along the oesophagus down to the oesophagocardiac junction. A simultaneously working abdominal team helps remove the oesophagus, which is then replaced by a stomach tube. Although the method is still under evaluation, results to date have been especially good for small distal tumors, especially adenocarcinomas.

Thoracoscopic oesophagectomy with intrathoracal stapled anastomosis

Techniques for intrathoracal stapler anastomosis under thoracoscopic control were studied and developed in an experimental program. Since this procedure is possible from two directions, both directions were evaluated. Two different techniques, a transoral and a transhiatal, resulted. For the transoral technique the stapler is inserted from above. The anvil, which is connected to a wire, is drawn into the abdomen together with the distal oesophagus. Retracting the wire pulls both the anvil and the stomach tube up into the thorax after the insertion of the anvil. The second technique requires a special attachment to introduce the anvil transhiatally into the thorax and into the oesophageal stump. The gastric tube is pushed into the thorax by the stapler gun, which is inserted into the stomach through an antrostomy. The insertion of the anvil into the oesophageal stump can also be achieved with the support of a flexible endoscope including a polyp snare.

Combined thoracoscopic and laparoscopic oesophagectomy and oesophagogastric reconstruction

Subtotal oesophagectomy and stapled oesophagogastric anastomosis is a favoured option for cure or palliation of oesophageal carcinoma. This approach currently involves a thoracotomy and laparotomy exposing the patient to the attendant pulmonary and intrathoracic complications. Alternative approaches to oesophagectomy without thoracotomy have failed to diminish the complication rate and may compromise the chance of cure. An endoscopic approach to the oesophagus is considered to be an evolving solution because it removes the need for thoracotomy and laparotomy but adheres to established oncologic principles. In order to assess the feasibility of complete endosurgical oesophagectomy and immediate reconstruction a non-survival study using 10 pigs was undertaken. Under general anaesthesia a 3-step operation was performed consisting of thoracoscopic oesophageal dissection, laparoscopic gastric mobilisation and thoracoscopic oesophagogastric anastomosis using a circular endoluminal stapler (Stealth-Ethicon). Conversion to open surgery was required only once during a gastric dissection, and all anastomoses were safely constructed thoracoscopically. In three animals small anastomotic tears were repaired with endoscopically-placed sutures. Three animals died intraoperatively, two from an anaesthetic complication prior to the introduction of intra-operative monitoring, and the other following haemorrhage from an hepatic vein traumatised by a liver retractor. This study has shown that endosurgical oesophagectomy is technically feasible and stapled oesophagogastric anastomosis can be performed in a comparable manner to the conventional procedure.

Laparoscopic treatment of common bile duct stones. Phantom experiments using electrohydraulic and pulsed dye laser lithotripsy

To evaluate the feasibility of laparoscopic transcystic lithotripsy of common bile duct stones, a phantom model comprising bovine liver and biliary tract tissue integrated within a laparoscopic trainer was built. A 9 French cholangioscope was introduced via the cystic duct into the common bile duct in which a human gall stone of known composition had been introduced. Lithotripsy was performed using either a laser or electrohydraulic probe passed through the working channel of the cholangioscope following which the stone fragments were manipulated into the duodenum through the papilla of Vater using the choledochoscope. A total of 20 lithotripsies with each energy form were performed. Lithotripsy was successful in breaking the stones into fragments smaller than 6 mm. The energy expenditure was comparable with a mean of 49 J for laser lithotripsy (range 9 to 159 J), and 53 J (range 16 to 160 J) for electrohydraulic wave lithotripsy. The lithotripsy time measured from introduction of the cholangioscope until its removal was a mean of 30 minutes for electrohydraulic wave lithotripsy and 41 minutes for dye laser lithotripsy. This difference was statistically significant. Macroscopic tissue damage to the common bile duct wall was not observed following any procedure. An additional experiment was performed to evaluate damage that could be caused to the wall of the common bile duct. Both electrohydraulic shock wave and pulsed dye laser lithotripsy without optical feedback regulation caused severe tissue defects when there was tissue contact or distance less than 2 mm. With optical feedback regulation however, no tissue damage was induced by laser lithotripsy.(ABSTRACT TRUNCATED AT 250 WORDS)

Transanal endoscopic microsurgery using a newly designed multifunctional bipolar cutting and monopolar coagulating instrument

In order to save time for changing instruments and minimize thermal damage in underlying tissue caused by monopolar high frequency in transanal endoscopic microsurgery (TEM), we have developed a new electrosurgical instrument, in which four functions are integrated: bipolar cutting, monopolar coagulation, suction and irrigation. The new device and the conventional monopolar knife were tested during both in vitro and in vivo experiments to compare the thermal alterations and effects on operating time. In vitro experiments demonstrated that the extent of thermal alterations created by bipolar cutting was less than in the case of monopolar cutting in the fresh porcine liver and bovine rectum. The mean severity scores for carbonization, coagulation and vacuolization in the resected mucosae obtained during in vivo animal operations by the bipolar procedure were 2.09, 2.27 and 1.36, respectively, whereas those obtained using the monopolar technique were 2.64, 2.82 and 2.36, respectively. The new device required an average operation time of 673.5 seconds, whereas the conventional setup required 701.9 seconds to resect the same diameter of rectal mucosa. Reduced operation time with the new device was mainly attributable to the reduced time needed for changing the instruments for hemostasis. The decreased thermal damage to the underlying bowel wall produced by the bipolar procedure should reduce the incidence of such operative complications in TEM (Transanal Endoscopic Microsurgery, developed in 1983 by Buess, Theis and Hutterer) as perforation, dehiscence in the suture line or post-polypectomy coagulation syndrome. By quickly switching between the multiple functions of this new device a clear operative field can always be achieved, thus decreasing operation time and bleeding.(ABSTRACT TRUNCATED AT 250 WORDS)

LaparoLith. A new instrument for stone fragmentation in laparoscopic cholecystectomy

Laparoscopic cholecystectomy can be performed with incisions of a maximum diameter of 10 mm. The removal of a stone-filled gallbladder at the end of an operation via the 10-mm port needs often-extensive tissue-consuming manipulations for stone removal or minilaparotomy. Stone fragmentation can be achieved by mechanical crushing and by ultrasound-, electrohydraulic-, and tunable dye laser lithotripsy. The clinical employment of the LaparoLith (Baxter Healthcare Corporation), an instrument which allows mechanical fragmentation of stones inside the gallbladder, is presented here. We have used the LaparoLith in nine patients and have been successful in stone fragmentation in seven of these. The LaparoLith seems to be helpful in laparoscopic cholecystectomy, preventing extension of the subnavel incision.

[Laparoscopic cholecystectomy]

Laparoscopic cholecystectomy has been accepted clinically in a very short time. Following an intensive training-course for manual dexterity clinical experience should be achieved in carefully selected cases. After a certain number of cholecystectomies the majority of cholecystectomies can be performed laparoscopically. The complication rate of laparoscopic cholecystectomy in the hand of a well trained surgeon seams to be comparable or even smaller than in conventional procedure. The patients have significantly less pain and bodily activity starts early. The postoperative time in hospital in our clinic is two to three days. The rehabilitation-time could be shortened.

Technique and results of transanal endoscopic microsurgery in early rectal cancer

The anatomy of the pelvis makes it difficult to perform local excisions in the rectum when the tumor is some distance from the anal verge. We have, therefore, developed a new minimally invasive technique for tumor resection. A rectoscope with a 40-mm diameter permits tumor resection under stereoscopic control in the gas-dilated rectal cavity. Excisions in full-thickness technique up to segmental resections with end-to-end anastomosis can be performed. In selected cases, local excision of a small rectal cancer can be regarded as appropriate treatment. However, most local resections of carcinomas are performed when removal of an adenoma is planned, and the postoperative histology shows a carcinoma. Since 1983, we have operated on 326 patients, 274 who have been enrolled in a prospective clinical trial. Definitive histologic examination proved that 74 of these tumors were carcinomas. The rate of severe complications in patients with carcinomas was 9%, and the mortality rate was 0%. The advantages of this new technique are: The stereoscopic magnified view in the gas-dilated rectum allows precise surgery in an operative field that is otherwise difficult to reach. During the postoperative period, minimal discomfort and pain result in a short hospitalization.

[Sulbactam in combination with mezlocillin, piperacillin or cefotaxime. Clinical and bacteriological results in the treatment of severe bacterial infections]

An open multicenter study on inpatients of 12 german hospitals was performed to investigate efficacy and safety of sulbactam in combination with mezlocillin, piperacillin or cefotaxim in severe bacterial infections. In total 155 patients were enrolled. The following infections were diagnosed: 48 lower respiratory tract infections, 66 intraabdominal infections, 34 skin/soft tissue infections including post operative wound infections and 5 complicated urinary tract infections. 55 patients received 3 daily doses of 4 g mezlocillin + 1 g sulbactam, 52 patients received 3 daily doses of 4 g piperacillin + 1 g sulbactam and 48 patients received 3 daily doses of 2 g cefotaxim + 1 g sulbactam. Antibiotics and sulbactam were administered concomitantly via intravenous short infusion. Mean duration of therapy was 8 days. Endpoints for assessment of therapeutic efficacy were cure (complete resolution of pretreatment signs and symptoms of the infection) or improvement (marked reduction or partial disappearance or pretreatment signs and symptoms, no further antibiotic therapy required) as well as eradication of pretreatment pathogens. 141 (92%) of 153 evaluable patients were successfully treated (98 cures and 43 improvements), therapy failed in 12 patients (7.8%). Success rates of the 3 sulbactam combinations were almost identical: 91% for mezlocillin/sulbactam, 92% for piperacillin/sulbactam and 93% for cefotaxim/sulbactam. 106 patients (68.4%) were also bacteriologically evaluable. In these patients 192 bacterial pathogens were isolated prior to study therapy, 55 patients had mixed infections. In 96 patients (90%) pretreatment pathogens were eradicated (180 strains = 94%).(ABSTRACT TRUNCATED AT 250 WORDS)

[Massive hemorrhage from an "esophageal tumor": thoracic aortic aneurysm rupturing into the esophagus]

We report on an arteriosclerotic aneurysm of the descending aorta penetrating into the esophagus. On endoscopy it mimicked a bleeding esophageal tumour. The typical clinical course of aortoesophageal fistulas (AEF) exhibits Chiari's triad of midthoracic pain, sentinel arterial hemorrhage, usually hematomesis, and final exsanguination after a symptom-free interval. The various causes of AEF are discussed together with the respective diagnostic and therapeutic problems.

[Uses and advantages of a computer-assisted microbiologic diagnosis and database system for antibiotic therapy in surgery]

To demonstrate the value of a computer assisted microbiological diagnosis and database system for clinical use, epidemiological aspects of three important infections were investigated: urinary tract, respiratory tract and wound infections. The first two examples presented revealed significant differences in incidence of pathogens between a single patient group and the overall statistic. The third example demonstrates that even within a department susceptibility patterns of staphylococcus epidermidis were changing in dependence of the ward investigated. In the last example the evaluation of susceptibility testing revealed changing patterns of some pathogens during the observation periods. By means of a computer assisted diagnosis and database on file at the moment of diagnosis thus allowing statistical evaluations at every time within a few hours. The clinician provided with actual data concerning his ward or department may administer an empiric therapy according to the real situation. Besides this, automated susceptibility testing may shorten the time required for diagnosis up to 24 h, thus further contributing to a more rational antimicrobial therapy. In conclusion computer assisted diagnosis and automated instruments support the clinician by means of actual epidemiological data and rapid reporting in choosing and controlling antimicrobial therapy.

Benefit and advantage to clinicians of a computer-assisted microbiological diagnosis and database system

Computer-assisted diagnostic systems may accelerate transmission of microbiological reports and facilitate evaluation of the epidemiological situation and thus improve the collaboration between microbiologists and clinicians. This possible benefit is demonstrated by four examples. It became evident that incidences of pathogens in urinary tract and respiratory tract infections varied within a great range, depending on patient groups and clinical departments involved. Even within a department, different incidences of penicillin G and oxacillin-resistant coagulase-negative staphylococci were demonstrated. An apparent homogeneity of distribution of pathogenic bacteria in a hospital tends to be the result of a nondiscriminating overall evaluation, thus necessarily misleading the clinician especially in empirical chemotherapy. In the last example the evaluation of susceptibility testing revealed changing patterns of some pathogens during the observation period. By rapid exchange of data between the laboratories and the clinical departments supplying the clinicians with information relevant for actual therapeutical decisions, an empiric therapy may change into a so-called calculated therapy based upon data directly related to the site of infection, department and susceptibility patterns.

[Experimental and clinical studies of the efficacy of an antimicrobial incision drape]

The antibacterial activity of an antimicrobial incise drape containing povidone-iodine was compared to a normal drape by experimental and clinical investigations. In vitro, no difference in the survival rate of six bacterial species depending on the kind of the drape, could be demonstrated. Clinical studies by contact cultures, postoperatively taken from the skin after removal of the drape, yielded no significant difference in the recolonisation of the skin during the operations. The importance of the preoperative, antimicrobial preparations of the skin is discussed.

[Comparative investigations on the organotropic carcinogenic effect of different N-nitroso compounds with rat after single and chronic treatment (author's transl)]

After the gavage of 200 mg N-nitrosodiethylamine per kg body weight only kidney tumors developed while long-term administration of 10 ppm N-nitrosodiethylamine induced esophageal tumors and hepatocellular carcinomas in female rats (SIV 50). This change of the organ-specific carcinogenic effect is not observed in experiments with N-methyl-N-nitrosobenzylamines substituted with a methyl group at the phenyl moiety. Both chronic treatment and single doses induced tumors of the esophagus and the pharynx.

[Change of toxicity and carcinogenicity of n-methyl-n-nitrosobenzylamine in rats by methylsubstitution at the c-atoms adjacent to nitrogen (author's transl)]

Substitution with a methyl group at the C-atoms adjacent to nitrogen of N-nitroso-N-methylbenzylamine (NMBA) results in a considerable reduction LD 50: N-nitroso-N-methylbenzylamine : 18 mg/kg (Druckrey et al., 1967) N-nitroso-N-methyl-(1-phenyl)-ethylamine (I) : 600 mg/kg N-nitroso-N-methyl-2-(2-phenyl)-propylamine (II) : 2100 mg/kg N-nitroso-N-ethyl-benzylamine (III) : 250 mg/kg Substitution with a methyl group at the methylene of the moiety of NMBA (NMPEA I) reduces also the carcinogenic activity, but it produces in all animals carcinomas of the oesophagus and the pharynx; the replacement of both H-atoms by methyl groups (NMPPA, II) causes under the condition chosen no development of tumors, because for the activation step no proton is available. The exchange of N-methyl by N-ethyl of NMBA (NEBA, III) however produces no change in the carcinogenicity.