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Biomedical subjects

N Rizk

Publications and source records attributed to N Rizk.

At least 37 records · Page 2Linked to original sources
PubMed1997

Retinoids augment the bystander effect in vitro and in vivo in herpes simplex virus thymidine kinase/ganciclovir-mediated gene therapy.

Metabolic cooperation via gap junctional intercellular communication (GJIC) is an important mechanism of the bystander effect in gene therapy using the herpes simplex virus thymidine kinase/ganciclovir (HSVtk/GCV) 'prodrug' system. Since retinoids have been reported to increase GJIC by induction of connexin expression, we hypothesized that these compounds could be used to augment the HSVtk/GCV bystander effect. Addition of all-trans retinoic acid increased GJIC in tumor cell lines, augmented expression of connexin 43, and was associated with more efficient GCV-induced in vitro bystander killing in cells transduced with HSVtk via either retrovirus or adenovirus vectors. This augmentation of bystander effect could also be seen in vivo. HSVtk-transduced tumors in mice treated with the combination of GCV and retinoids were significantly smaller than those treated with GCV or retinoids alone. These results provide evidence that retinoids can augment the efficiency of cell killing with the HSVtk/GCV system by enhancing bystander effects and may thus be a promising new approach to improve responses in gene therapy utilizing the HSVtk/GCV system to treat tumors or vascular restenosis.

Animals↗
PubMed1997

[Peroperative investigation of the common bile duct during laparoscopic cholecystectomy. Laparoscopic ultrasonography versus cholangiography. A prospective study of 150 cases].

From November 1994 to March 1996, 150 patients treated by laparoscopic cholecystectomy were included in a prospective study, in order to compare intraoperative cholangiography and laparoscopic ultrasound. The biliary tree was successively explored by the two methods in the systematic detection of common bile duct stones. The feasibility of laparoscopic ultrasound was 100 per cent. Cholangiography was performed in only 125 cases (83 per cent). The duration of the laparoscopic ultrasound exam was significantly shorter (11.6 vs 17.6 minutes, p = 0.0001). In this study, common bile duct stones were found in 14 cases (9 per cent). The detection rates with laparoscopic ultrasound and intraoperative cholangiography were similar. For laparoscopic ultrasound, sensitivity was 80 per cent and specificity was 99 per cent, versus 78 per cent and 97 per cent for cholangiography, respectively. The combination of the 2 examinations had a 100 per cent sensitivity and specificity. Laparoscopic ultrasound failed to recognize the intrapancreatic part of the bile duct (25 cases: 17 per cent), did not show anatomical abnormalities detected by cholangiography, but detected unsuspected digestive lesions. Laparoscopic ultrasound is safe repeatable, and non invasive, but a learning curve is necessary to increase this efficacy. Comparison of cost must be evaluated.

Adult↗
PubMed1997

[Laparoscopic correction of recurrent gastro-esophageal reflux following laparoscopic fundoplication (4 cases)].

A series of 98 laparoscopic fundoplications, included 7 cases (7.1%) of recurrent gastro-oesophageal reflux. Six of these cases occurred within 12 months of surgery. Four were successfully treated by a second laparoscopic procedure. The mean interval between the initial and corrective operations was 10 months. Factors related to failure were: technical errors, operative inexperience, obesity and the size of the hiatus hernia (when crural closure was not performed). Laparoscopic re-operation to was relatively easy and without mortality but had an increased risk of pleural effusions. The mean length of hospital stay for re-operations was identical to that of initial operations (4 days). No further recurrences were noted after a mean follow-up of one year (280-475 days). We conclude that early failures following laparoscopic fundoplication can be effectively dealt with laparoscopic surgery.

Adult↗
PubMed1997

[Laparoscopic resection of a bladder diverticulum].

The authors report a case of laparoscopic resection of a bladder diverticulum performed at the same time as endoscopic treatment of its presumed cause. Dissection of the diverticulum, particularly its neck, and dissection of diverticula of the ureter and vas deferens are facilitated by magnification of the video image. This approach is only indicated in particular anatomical sites (posterior). The results of this technique must be compared with those of conventional treatments.

Adult↗
PubMed1997

Inguinal hernia repair: totally preperitoneal laparoscopic approach versus Stoppa operation: randomized trial of 100 cases.

In a prospective randomized trial comparing the totally preperitoneal (TPP) laparoscopic approach and the Stoppa procedure (open), 100 patients with inguinal hernias (Nyhus IIIA, IIIB, IV) were followed over a 3-year period. Both groups were epidemiologically comparable. In the laparoscopic group, operating time was significantly longer (p = 0.01), but hospital stay (3.2 vs. 7.3 days) and delay in return to work (17 vs. 35 days) were significantly reduced (p = 0.01). Postoperative comfort (less pain) was better (p = 0.001) after laparoscopy. In this group, morbidity was also reduced (4 vs. 20%; p = 0.02). The mean follow-up was 605 days, and 93% of the patients were reviewed at 3 years. There were three (6%) recurrences after TPP, especially at the beginning of the surgeon's learning curve, versus one for the Stoppa procedure (NS). For bilateral hernias, the authors suggest the use of a large prosthesis rather than two small ones to minimize the likelihood of recurrence. In the conditions described, the laparoscopic (TPP) approach to inguinal hernia treatment appears to have the same long-term recurrence rate as the open (Stoppa) procedure but a real advantage in the early postoperative period.

Adult↗
PubMed1996

[Laparoscopic cholecystectomy in obese patients: 110 cases].

110 obese patients who underwent a laparoscopic cholecystectomy were compared with a group of controls, the operative time (108 mn), the conversion rate to laparotomy (4.5% vs 1.8%) and the incidence of drainage (26 vs 11%) were significantly raised in the obese patients. However there was no difference in the mortality (0), the feasibility of intraoperative cholangiography, the hospital stay, the morbidity or the time off work when compared with the controls. In particular the incidence of wound infections, thromboembolic or respiratory complications (frequent in conventional surgery on the obese) was not significantly different to the control group operated on laparoscopically. This study supports that laparoscopic approach is an elective procedure for obese patients.

Adolescent↗
PubMed1996

[What are abdominal painful syndromes of unexplained origin? Prospective study: 99 patients followed for three years].

99 patients, 67 of whom were female, with a mean age of 25.5 years, were admitted as emergencies between 1991 and 1992 for acute abdominal pain of unknown aetiology. The follow-up, carried out prospectively, was 100% at 1 month, 98% at 6 months, 95% at 1 year, 84% at 2 years. The patients were divided into 3 groups: group I: 42 patients only underwent investigations; group II: 31 underwent laparoscopy, and the appendix was left in place after being considered to be normal by the surgeon; group III: 26 underwent laparoscopic appendicectomy for a histologically normal appendix. For 90% of patients, the painful episode never returned. In the other cases the pain returned within one year, but there was no difference between the three groups (11.2%, 9.6%, 11.5%) (ns). The causes found at the second admission were largely genital, or rare diseases (Crohn, Spiegel hernia). 2 patients were operated for acute appendicitis, not recognized in Group I. In those who had a laparoscopy (Group II and III), the incidence of persistent pain was identical whether the appendix was considered to be normal by the operating surgeon or found to be normal histopathologically. This study suggests that: after admission for acute abdominal pain of unknown cause, the incidence of recurrence of pains is of the order of 10% within one year; the investigations carried out during the patient's admission, allowed the exclusion of serious diseases for three years; the risk of missing a true appendicitis is small (2.5%) and has no prognostic significance; the finding of a normal appendix during laparoscopy should not necessarily lead to its removal; one year follow-up is sufficient to assess the outcome of abdominal pain of unknown cause.

Abdominal Pain↗
PubMed1996

Gastroesophageal reflux: conventional surgical treatment versus laparoscopy. A prospective study of 61 cases.

Sixty-one patients with gastroesophageal reflux who did not respond to conventional medical treatment were treated in a prospective study, 29 by conventional surgery and 32 by laparoscopic methods. All underwent manometry and pH measurement preoperatively and at a follow-up of four months. There was no mortality, and the morbidity of the two groups was not significantly different at 3% and 5%. Hospital stay was significantly reduced (5.4 versus 8.9 days; p = 0.02) following laparoscopic treatment, and time off from work was 21.3 days versus 38.2 days (p = 0.02). The satisfaction index expressed by the patients was 65% at 1 month and 95% at 3 months. Dysphagia was observed in 30% of the patients at 1 month and in 3% at 4 months in both groups. The results of manometry and pH measurements at 4 months are comparable between open surgery and laparoscopy. There was one failure (3%) in the laparoscopic group caused by disruption of the valve. The mean pressure in the esophageal segment (expressed in mm Hg) changed in the two groups from 3.6 to 18.1 (p = 0.001). The results of this series show laparoscopic management of gastroesophageal reflux to be justified.

Adult↗
PubMed1996

[Laparoscopic colectomy. Techniques and indications].

Standard techniques for laparoscopic colectomy are currently well defined and are described here. Details are provided concerning facilities, equipment, and operative procedures for resection of the rectum, the left and right colons and total colectomy. Questions of indications are carefully addressed. Laparoscopic colectomy is an excellent indication for benign inflammatory as well as tumoral diseases. Inversely, there is some discussion concerning indications in colorectal cancer due to the risk of trocar tract metastasis. Based on data in the literature, the results of laparoscopic colectomy are analyzed together with the advantages of this technique in terms of mortality, morbidity, and hospitalization stay in comparison with conventional surgery.

Colectomy↗
PubMed1996

[Inguinal hernia. Pre-peritoneal laparoscopic surgery vs. the Stoppa procedure. A prospective randomized trial: 100 cases].

In a prospective randomized trial between totally pre peritoneal (TPP) laparoscopic surgery ant Stoppa procedure (open), 100 patients with groin hernia 'Nyhus IIIA, IIIB, IV) were included and followed during 3 years. Both groups were comparable. In the "laparoscopic" group, operating time was significatelly longer (p = 0.01) but hospital stay (3.2 vs 7.3 days) and delay to return to work (17 vs 35 days) were significantely reduced (p = 0.01 =. Post operative comfort (less pain) was better (p = 0.001) after laparoscopy. In this group, morbidity was also reduced (4% vs 20% p = 0.02). The mean follow up was 605 days and 93 per cent of the patients were reviewed at three years. There was 3 (6%) recurrence after TTP, specially in the beginning of the surgeon experience (learning curve) versus for the Stoppa (ns). In case of bilateral hernia, the authors suggest to use a large prosthesis than two little one to prevent recurrences. In these conditions, laparoscopics (TPP) approach of groin hernia treatment will have the same recurrence rate as open (Stoppa) procedure, but a real advantages in the early post operative period.

Adult↗
PubMed1996

[Can we recognize the pathological character of the appendix during laparoscopy? Prospective study: 81 cases].

In a prospective study of 81 patients, the appendix was photographed during a laparoscopy performed for pain in the right iliac fossa. An appendicectomy was performed in 65 patients, for the remaining 16, another cause for the pain was found and the appendix was left in place. The evaluation of the photographed appendix was formed afterwards by a group of 10 surgeons and compared with the histopathological results. In 20 cases (30%) the appendix was normal. In 7 (10%) minimal mucosal inflammation was found and in 38 (60%) acute appendicitis. All the surgeons correctly recognised acute appendicitis. The accuracy of recognition of a normal appendix was 70% overall, and the maximum risk of leaving an early form of appendicitis to evolve was 14%. We propose not removing an appendix judged to be normal during laparoscopy if no other cause for the pain is found. A short course of antibiotics would cover the low risk of allowing a very early appendicitis to develop.

Acute Disease↗
PubMed1996

[Contribution of laparoscopic echography in the staging of curative resection of cancer of the pancreatic head (26 cases)].

In a prospective study, 26 patients with pancreatic and peri-ampullary cancer were evaluated with ultrasound (US), computerized tomography (CT Scan), endoscopic ultra sonography (EUS) and laparoscopic ultrasound (LUS). Sensitivity of US and CT scan were comparable, although CT scan seems better to evaluate the size of the tumor and for lymph node detection. 50 per cent of patients had a criterion for noncurative resection. EUS (16 cases) had the best sensitivity (100 per cent) for the staging of small tumors (less than 20 millimeters), detection of adjacent nodes and the relation between tumor and mesenteric and portal veins. EUS was not able to detect peritoneal and/or liver micro-metastases (44 per cent of them would be missed by this examination alone). The criterion for noncurative resection was 56.6 per cent. LUS exactly assessed all tumors larger than 3 centimeters (100 per cent). The accuracy compared with endoscopic ultra-sonography was not as good for small tumors and adjacent nodes, was equal for the venous relations with tumors, but better concerning micro-peritoneal or hepatic metastasis. The criterion for noncurative resection was 80 per cent. These results suggest to use of US and CT as first-line procedures in the pre-operative staging and assessment of resectability of pancreatic cancers. When the patient does not appear to have disseminated lesions (50 per cent), endoscopic ultra-sonography gives a good estimation of the size of the tumor, node assessment and vascular relations. LES could be the first step for a curative surgical treatment LES revealed to discover 15 to 30 per cent of unknown micrometastases and avoided useless laparotomy in these patients.

Adult↗
PubMed1996

[Is there an age limit for laparoscopic cholecystectomy? Apropos of 61 patients over 85 years of age].

Bilary surgery in the elderly is associated with high morbidity and mortality. The aim of this prospective study was to determine benefits of laparoscopic cholecystectomy in patients over 85 years. From August 1990 to January 1996, 61 patients (50 women, 11 men) aged over 85 years had laparoscopic cholecystectomy. Thirty seven (60.6%) were at high surgical risk (ASA III). In more than 40% of cases complications were present (acute cholecystitis, gallbladder empyema). Nine patients (14.7%) had choledocholithiasis. Ten (16.3%) conversions were necessary, in 5 cases for choledocholithiasis. Overall morbidity was 9.8%: 2 bibary leaks, 1 pneumonia, 1 urinary injection and 1 lymphangitis. There was no mortality. With excellent pre-operative risk evaluation, laparoscopic cholecystectomy is better than laparotomy cholecystectomy. Laparoscopic cholecystectomy has a low morbidity in the elderly and it allows curative treatment of gallstones complicated or not.

Age Factors↗