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Biomedical subjects

A Darzi

Publications and source records attributed to A Darzi.

At least 127 records · Page 7Linked to original sources
PubMed1998

Validation of virtual reality to teach and assess psychomotor skills in laparoscopic surgery: results from randomised controlled studies using the MIST VR laparoscopic simulator.

Objective assessment of surgical technique is currently impossible. A virtual reality simulator for laparoscopic surgery (MIST VR) models the movements needed to perform minimally invasive surgery and can generate a score for various aspects of psychomotor skill. Two studies were performed using the simulator: first to assess surgeons of different surgical experience to validate the scoring system; second to assess in a randomised controlled way, the effect of a standard laparoscopic surgery training course. Experienced surgeons (> 100 laparoscopic cholecystectomies) were significantly more efficient, made less correctional submovements and completed the virtual reality tasks faster than trainee surgeons or non-surgeons. The training course caused an improvement in efficiency and a reduction in errors, without a significant increase in speed when compared with the control group. The MIST VR simulator can objectively assess a number of desirable qualities in laparoscopic surgery, and can distinguish between experienced and novice surgeons. We have also quantified the beneficial effect of a structured training course on psychomotor skill acquisition.

Cholecystectomy↗
PubMed1998

Transient reduction in gastric acid secretion following gastric mucosal laser irradiation.

This study assessed a novel approach using defocused carbon dioxide (CO2) laser irradiation on the gastric mucosal surface to reduce gastric acid output. Ninety-six Sprague-Dawley rats were randomised to three groups: control, surgical highly selective vagotomy (surgical-HSV), and gastric mucosal irradiation (laser-M). Cysteamine-induced peptic ulceration was studied, including ulcer index (product of the total number of ulcers by the sum of the ulcer length), at 4 weeks and 20 weeks. The mean ulcer index in the surgical-HSV group was significantly reduced compared with controls at 4 weeks and at 20 weeks. The mean ulcer index in the laser-M group was significantly reduced compared with controls at 4 weeks but not at 20 weeks. Histologic analysis did not reveal any mucosal changes in parietal cell mass at 4 weeks and at 20 weeks. The results show a transient antiulcer effect produced by the gastric mucosal irradiation seen at 4 weeks and abolished by 20 weeks. This data supports the feasibility of endoscopic management of peptic ulcer disease.

Animals↗
PubMed1997

Thromboembolism prophylaxis during laparoscopic cholecystectomy.

BACKGROUND: The aim of this study was to determine current UK practice with regard to thromboembolism prophylaxis during laparoscopic cholecystectomy. METHODS: Postal questionnaires were sent to 800 members of the Association of Surgeons; replies were received from 551 surgeons (69 per cent) of whom 417 practised laparoscopic cholecystectomy. RESULTS: Heparin was prescribed to all patients by 74 per cent, and selectively by 20 per cent, of respondents. Surgeons who performed fewer than ten laparoscopic cholecystectomies per annum were significantly less likely to use heparin (P < 0.001) and more likely to believe that heparin produces significant adverse bleeding (P < 0.01). Thirty per cent of respondents used low molecular weight heparin. Stocking to deter thromboembolism were used by 74 per cent, and pneumatic compression by 37 per cent. Indications for heparin varied considerably and were not influenced by Thromboembolic Risk Factors (THRIFT) guidelines. Only 20 per cent of respondents considered that thromboembolism was a problem; 91 per cent reported that they had never experienced a thromboembolic complication following laparoscopic cholecystectomy. CONCLUSION: The rate of thromboembolism after laparoscopic cholecystectomy is unknown but most surgeons believe the risk is very low. Surgeons' attitudes towards thromboembolism prophylaxis are variable, but most experienced surgeons use low-dose heparin.

Adult↗
PubMed1997

Initial experience with an absorbable laparoscopic ligation clip.

BACKGROUND: Laparoscopic surgery requires secure and safe methods of ligation and haemostasis. This study evaluated the efficacy of an absorbable ligation clip with a novel compression closure mechanism. METHODS: A new compression-closure absorbable clip was compared with currently available absorbable and non-absorbable clips used in a variety of laparoscopic procedures in 12 centres worldwide. RESULTS: At follow-up to 3 months after the procedure, no complications specific to the use of the compression-closure clip were detected. Operator satisfaction with the clip was high, with criticism directed at its relatively large size. CONCLUSION: This new clip is as safe and effective as presently available metal and absorbable clips in providing haemostasis and securing tubular structures.

Adolescent↗
PubMed1997

Endoscopically guided percutaneous repair of inguinal hernia through a 2-cm incision. Minihernia repair.

BACKGROUND: The laparoscopic repair of inguinal hernia is still controversial. Transabdominal preperitoneal repair violates the peritoneal cavity and may result in visceral injuries or intestinal obstruction. The laparoscopic extraperitoneal approach has the disadvantage of being technically demanding and requires extensive extraperitoneal mobilization. The Lichtenstein repair gives good long-term results, is easy to learn, can be performed under local anesthesia, but requires a larger incision. METHODS: We describe a novel percutaneous tension-free prosthetic mesh repair performed through a 2-cm groin incision. The inguinal canal is traversed with the aid of a 5-mm video-endoscope and the canal is widened using specially designed balloons. Spermatic cord mobilization, identification and excision of the indirect sac, and posterior wall repair are carried out under endoscopic guidance. RESULTS: Between October 1993 and July 1995, 85 primary inguinal hernia repairs (48 indirect and 33 direct) were performed on 81 patients (80 men, one woman) by the author (A.D.). The mean age was 41 years (range 17-83 years). Six repairs were performed under local anesthetic. Mean operative time was 42 min (range 25-74). Mean hospital stay was 1.2 days (0-3 days). The mean return to normal activity was 8 days (2-10 days). Eight complications have occurred: a serous wound discharge, two scrotal hematomas, a scrotal swelling that resolved spontaneously, wound pain lasting 2 weeks, an episode of urinary retention, and two recurrences early in the series (follow-up 1-22 months). CONCLUSION: The endoscopically guided percutaneous hernia repair avoids the disadvantages of laparoscopy (i.e., lack of stereoscopic vision, reduced tactile feedback, unfamiliar anatomical approach, risk of visceral injury), yet the use of endoscopic instrumentation allows operation through a 2-cm incision. The minihernia repair thus combines the virtues of an open tension-free repair with minimal access trauma.

Adolescent↗
PubMed1997

A solitary benign lymphoid polyp of the rectum in a 51 year old woman.

A 51 year old woman presented with rectal bleeding from a mass lying just above the dentate line. Multiple biopsies were taken before the diagnosis of a benign lymphoid polyp was made. This is a rare condition that more commonly presents in children and poses a diagnostic challenge.

Diagnosis, Differential↗
PubMed1997

The interventional magnetic resonance unit--the minimal access operating theatre of the future?

Interventional magnetic resonance units give the surgeon the potential to use intraoperative imaging to guide the surgical procedure. The advantages of magnetic resonance (MR) over other intraoperative imaging modalities include excellent soft tissue resolution, lack of ionizing radiation and the ability to reconstruct images in any desired plane. Postulated advantages include the ability to confirm adequate tumour resection, reduction in procedure magnitude and complication rate, shortened inpatient stay and the development of novel minimally invasive techniques including the use of thermal energy to destroy lesions. Fully MR compatible anaesthetic and patient monitoring equipment is available. However, before the MR-guided minimally invasive surgery can become a reality, much work is required in the assessment and development of MR compatible surgical instrumentation and equipment. This review describes the testing and development of instruments and equipment for MR image-guided surgery that we have undertaken. We describe the techniques we employ for open and minimal access surgery within this unique environment. The difficulties of operating within such an environment and the safety issues that this engenders are discussed. The current applications of intraoperative MR in the main surgical specialities are reviewed, and possible future areas of development for MR-guided minimally invasive surgery described.

Endoscopy↗
PubMed1995

Laparoscopic colonic surgery.

Laparoscopic surgical techniques have recently entered the field of colorectal surgery. Because the laparoscopic approach has revolutionized biliary surgery, it is hoped that similar advances will be possible in the more elderly population with colorectal disease. Early experience suggests that such advances have not been achieved and there is concern about developing minimal access surgical techniques in the face of potentially curable cancer. This article reviews the current state of knowledge based on published series; however, the current lack of controlled data in patients with extended follow-up makes this area highly controversial. Suggestions regarding the future of laparoscopic surgery are made and include the establishment of a national register and the development of controlled randomized trials.

Colon↗
PubMed1995

Endoscopically guided surface repair of inguinal hernia.

A novel tension-free prosthetic mesh repair for an inguinal hernia is described. This is performed through a 2-cm groin incision and the inguinal canal is traversed with the aid of a 5-mm videoendoscope. Spermatic cord mobilization, identification and excision of the indirect sac, and posterior wall repair are carried out under endoscopic guidance. Between October 1993 and January 1994, 22 primary unilateral hernia, and two bilateral repairs were undertaken. The mean (range) age was 47 (35-64) years in 23 men and one woman. The mean (range) operative time was 42 (35-58) min. All patients left hospital on the day after surgery. One patient developed a scrotal swelling that required a scrotal support.

Adult↗
PubMed1995

Laparoscopic abdominoperineal excision of the rectum.

In laparoscopic abdominoperineal resection of the rectum (LAP-AP) an abdominal incision is completely avoided as the tumor is delivered through the perineal incision. It is our belief that the view provided in the pelvis by laparoscopy is significantly better than at laparotomy and allows excellent anatomical definition and meticulous dissection. In this study we compared the adequacy of excision of the first 12 patients undergoing LAP-AP to the last 16 patients undergoing open abdominoperineal resection (OP-AP). In all patients the procedure was carried with curative intent for adenocarcinoma and the Dukes staging and Jass score's were similar in both groups. [table: see text] The data demonstrate similar nodal harvest in both groups as well as extent of radial excision. However, two patients in the open group had microscopic radial margin involvement despite being microscopically clear at surgery. We conclude that although long-term follow-up is required to address the issue of local cancer recurrence, laparoscopic rectal dissection appears as good as open surgery and may allow a more precise assessment of excision margins.

Adult↗