Biomedical subjects
Publications and source records attributed to N Rizk.
A technique for the etching of biological materials by accelerated nitrogen ions is described. Upon exposure to such a beam, tobacco mosaic virus becomes thinner in diameter and the head of T4 becomes smaller. Experiments on radioactively labeled T4 suggest that the particle's protein is more susceptible to removal by the incident ions, and that the residual material is predominantly nucleic acid.
AIM: Prospective evaluation of the results of laparoscopic ultrasound and cholangiography to investigate choledocholithiasis and detect variations in biliary anatomy during laparoscopic cholecystectomies. METHODS: The biliary trees of 600 patients who underwent laparoscopic cholecystectomy were routinely explored by laparoscopic ultrasound and cholangiography. RESULTS: Laparoscopic ultrasound was performed in all 600 cases. Cholangiography was performed in 498 (83%). Laparoscopic ultrasound required less time than cholangiography: 10.2 minutes versus 17.9 minutes (P=0.0001). Common bile duct stones were detected intraoperatively in 40 cases (7%). Both methods were equally effective. The sensitivity of laparoscopic ultrasound was 80% and its specificity 99%. For cholangiography these values were 75% and 98% respectively. For laparoscopic ultrasound, false positives and false negatives were noted in the first 45 cases of individual trainees. Nevertheless, cholangiography showed 30 anatomical anomalies and laparoscopic ultrasound only 15. CONCLUSION: Laparoscopic ultrasound can be performed rapidly and in all cases. Results are comparable to cholangiography in the detection of common duct stones. Individual training is necessary to optimize efficacy. Anatomical anomalies are often missed.
The laparoscopic treatment for gastroesophageal reflux disease (GERD) by partial (PF) or total (TF) fundoplication is the current surgical treatment of choice after failure of appropriate medical treatment. The overall results with fundoplication include the initial learning period during which the rate of complications, and failures are assumed to be greater. The aim of this study was to compare the results of laparoscopic treatment for GR in 3 groups of consecutive patients in order to determine the effect of the learning period and the experience on the technique and the outcome. One hundred and fifty patients (84 men and 66 women) with an average age of 52.2 years (18 to 78) were included. Surgery was indicated for failure or early relapse following the end of medical treatment. The preoperative work-up (endoscopy, barium meal or oesophageal pH monitoring) was governed by the clinical picture. The choice between TF and PF was based on the results of pH monitoring. Three groups of 50 patients around were chronologically defined. The parameters that were examined were: the operative technique; the conversion rate; the mortality and morbidity rate; the duration of surgery and hospitalization and the results at short and medium term follow-up. The three groups were comparable with respect to patient characteristics and the nature of their GERD. All patients had an endoscopy, 91% a barium meal, 77.5% underwent esophageal manometry and 67% pH monitoring. One hundred and thirty two patients had a TF and 18 had a PF. Rosetti's type TF became the reference procedure (80.3% in group III) and closure of the diaphragmatic crura was performed systematically in group III (100%). The duration of surgery was significantly reduced between group I and the two other groups (138, 100, 80 mn.). The rate of conversion, due to a variety of causes, decreased from 10.2% to 4% and then 0%. The average duration of hospitalization decreased from 5.8 to 4.2 days (p = 0.01). There was no mortality and the morbidity rate decreased from 14.3% to 4% and then 0%. There was 7 cases of relapse (4.6%), 5 in group 1 (10.2%) and 2 in group II (4%), with no cases in group III although the follow-up is shorter. There is an effect of the learning curve on the outcome of treatment for GR and this must be taken into account in the training of surgeons (training within experienced departments and "guidance" during their initial interventions) and also in publications in order to allow a more accurate comparison of the different treatments for GERD.
In a prospective controlled trial comparing postoperative course, laparoscopic hernia repair totally pre-peritoneal approach appears significatively painless and more comfortable than Shouldice operation. Three criterions were used: pain questionnaire, visual scale, and antalgic use, during three days. These results partially explain a shorter delay to return to work (12 vs 31 days) after "laparoscopic treatment".
61 patients with aggressive gastro-esophageal reflux have been prospectively treated, 29 by open surgery and 32 by laparoscopy. There is no mortality and the morbidity is not significantly different (3 per cent vs 5 per cent). Hospital stay is strongly reduced in the laparoscopic group (5.4 days vs 8.9 days p = 0.02). Either the period of no professional activity (21.3 days vs 38.2 days p = 0.02). In both group, dysphagia is noted in 30% of the patients at 1 month and 3% at 4 months. All patients have had pre-operatively a mano-Ph-metry evaluation. At 4 months, the follow-up rate is 100% and all patient have been controlled with a 24 hours mano-Ph-metry. There is no difference between open and laparoscopic surgery. The mean SIO pressure had increased in both group from 3.6 mmHg to 18.1 mmHg (p = 0.001). There is only one failure in the beginning of the learning curve (4th patients in the "laparoscopy group" (3.1%). These study suggest that laparoscopic treatment could be proposed in the majority of failures of medical treatment in gastro-oesophageal reflux.
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