Afshin Alijani

Mechanical properties of the human abdominal wall measured in vivo during insufflation for laparoscopic surgery

BackgroundCarbon dioxide insufflation of the peritoneal cavity for laparoscopic surgery offers a unique opportunity to measure some mechanical properties of the human abdominal wall that hitherto have been difficult to obtain.MethodsThe movement and change of the abdominal wall during insufflation to a pressure of 12 mmHg was studied in 18 patients undergoing laparoscopic surgery using a remote motion analysis system that does not compromise the sterility of the operative filed. These data together with the known abdominal wall thickness of each patient (measured by preoperative ultrasound scanning) enabled estimates of mechanical stiffness.ResultsThe findings showed that the abdominal wall changes from a cylinder to a dome during inflation, and that its area is increased by 15%. A volume, averaging 1.27 × 10−3m3, results from expansion, reshaping of the abdominal wall, and displacement of the diaphragm. The abdominal wall is stiffer in the transverse plane than in the sagittal plane (Young’s modulus, 42.5 ± 9.0 kPa vs 22.5 ± 2.6 kPa; p = 0.03; paired t-test).ConclusionsMeasurements of mechanical properties of the abdominal wall in patients undergoing laparoscopic surgery were obtained using a remote motion analysis system.

Clinical outcomes of a percutaneous cholecystostomy for acute cholecystitis: a multicentre analysis

BACKGROUND The aim of this study was to review a series of consecutive percutaneous cholecystostomies (PC) to analyse the clinical outcomes. METHODS All patients who underwent a PC between 2000 and 2010 were reviewed retrospectively for indications, complications, and short- and long-term outcomes. RESULTS Fifty-three patients underwent a PC with a median age was 74 years (range 14-93). 92.4% (n = 49) of patients were American Society of Anesthesiologists (ASA) III and IV. 82% (43/53) had ultrasound-guided drainage whereas 18% (10/53) had computed tomography (CT)-guided drainage. 71.6% (n = 38) of PCs employed a transhepatic route and 28.4% (n = 15) transabdominal route. 13% (7/53) of patients developed complications including bile leaks (n = 5), haemorrhage (n = 1) and a duodenal fistula (n = 1). All bile leaks were noted with transabdominal access (5 versus 0, P = 0.001). 18/53 of patients underwent a cholecystectomy of 4/18 was done on the index admission. 6/18 cholecystectomies (33%) underwent a laparoscopic cholecystectomy and the remaining required conversion to an open cholecystectomy (67%). 13/53 (22%) patients were readmitted with recurrent cholecystitis during follow-up of which 7 (54%) had a repeated PC. 12/53 patients died on the index admission. The overall 1-year mortality was 37.7% (20/53). CONCLUSIONS Only a small fraction of patients undergoing a PC proceed to a cholecystectomy with a high risk of conversion to an open procedure. A quarter of patients presented with recurrent cholecystitis during follow-up. The mortality rate is high during the index admission from sepsis and within the 1 year of follow-up from other causes.

Abdominal Wall Lift Versus Positive-pressure Capnoperitoneum for Laparoscopic Cholecystectomy: Randomized Controlled Trial

Objective:To compare intraoperative cardiac function, postoperative cognitive recovery, and surgical performance of laparoscopic cholecystectomy with abdominal wall lift (AWL) versus positive-pressure capnoperitoneum (PPCpn). Summary Background Data:AWL has been proposed as an alternative approach to PPCpn to avoid adverse cardio-respiratory changes. However, the workspace obtained with the AWL is less optimal than PPCpn and previous studies documenting delayed postoperative recovery of consciousness following PPCpn have not assessed mental alertness despite its importance. Methods:Forty operations were randomized into AWL and PPCpn. A standard anesthetic protocol was followed. Cardiac indices were measured with an esophageal Doppler machine. An auditory vigilance test was used to measure alertness level following extubation. All operations were videotaped and human reliability assessment techniques were used to identify surgical errors. Results:There was a significant reduction in cardiac output during the first 20 minutes following CO2 insufflation in the PPCpn group, whereas in the AWL group it did not exhibit any significant change. Patients in AWL arm had better vigilance scores at 90 and 180 minutes following extubation compared with the PPn group (P < 0.05). Significantly more surgical errors were observed during surgery with AWL than with PPCpn (7.1 ± 1.1; versus 2.9 ± 0.4; P = 0.001). Conclusions:The AWL approach avoids fall in cardiac output associated with PPCpn during laparoscopic surgery and is associated with a more rapid recovery of postoperative cognitive function compared with PPCpn. However, AWL increases the level of difficulty in the execution of the operation.

Abdominal wall lift systems in laparoscopic surgery: gasless and low-pressure systems.

Positive pressure pneumoperitoneum (12 mm Hg) is associated with adverse physiologic effects that can prove detrimental to certain high-risk patients with diminished cardiorespiratory reserve. Mechanical abdominal wall lift (AWL) has been proposed as an alternative method of exposure in laparoscopic surgery to obviate or minimize these adverse physiologic effects, the risk of CO2 embolism in trauma patients, and tumor dissemination in patients undergoing laparoscopic surgery for cancer. This article reviews the systems available for AWL, the clinical applications of the technique, and the findings of the randomized controlled trials that compare AWL with conventional pneumoperitoneum. AWL systems do appear to reduce the adverse cardiovascular and respiratory effects, but they do so at the expense of surgical exposure, which is less optimal than that provided by the positive-pressure pneumoperitoneum. This reduced exposure increases the execution difficulty of the operation and, hence, the operating times. This problem is overcome by combination of AWL with low-pressure (3 to 4 mm Hg) pneumoperitoneum. This combination provides good surgical exposure without adverse cardiovascular consequences. Copyright

Meta-analysis of Prolene Hernia System mesh versus Lichtenstein mesh in open inguinal hernia repair

BACKGROUND This study was designed to systematically analyse all published randomized clinical trials comparing the Prolene Hernia System (PHS) mesh and Lichtenstein mesh for open inguinal hernia repair. METHOD A literature search was performed using the Cochrane Colorectal Cancer Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials in the Cochrane Library, MEDLINE, Embase and Science Citation Index Expanded. Randomized trials comparing the Lichtenstein Mesh repair (LMR) with the Prolene Hernia System were included. Statistical analysis was performed using Review Manager Version 5.1 software. The primary outcome measures were hernia recurrence and chronic pain after operation. Secondary outcome measures included surgical time, peri-operative complications, time to return to work, early and long-term postoperative complications. RESULTS Six randomized clinical trials were identified as suitable, containing 1313 patients. There was no statistical difference between the two types of repair in operation time, time to return to work, incidence of chronic groin pain, hernia recurrence or long-term complications. The PHS group had a higher rate of peri-operative complications, compared to Lichtenstein mesh repair (risk ratio (RR) 0.71, 95% confidence interval 0.55-0.93, P=0.01). CONCLUSION The use of PHS mesh was associated with an increased risk of peri-operative complications compared to LMR. Both mesh repair techniques have comparable short- and long-term outcomes.

Systematic review and meta-analysis of the role of mental training in the acquisition of technical skills in surgery

BACKGROUND Mental training is rehearsal of mental imagery without physically performing the task. The aim of the study was to perform systematic review and meta-analysis on all the available data to evaluate the role of mental training in the acquisition of surgical technical skills. METHODS The following search databases were used: EMBASE, MEDLINE, Web of Science, Clinicaltrials.gov.uk, SIGN guidelines, NICE guidelines, and Cochrane review register. Meta-analysis was performed using Revman 5.2 statistical software. RESULTS There were a total of 9 randomized controlled trials with 474 participants, of which 189 participants received mental training. Five randomized controlled trials concluded positive impact of mental training. Mental training group did not show any significant improvement in overall performance of the task carried in each study (P = .06). CONCLUSION Mental training can be used as an important supplementary tool in learning surgical skills when run in parallel with physical training and applied to trainees with some experience of the skill.

Quality review of an adverse incident reporting system and root cause analysis of serious adverse surgical incidents in a teaching hospital of Scotland

BackgroundA significant proportion of surgical patients are unintentionally harmed during their hospital stay. Root Cause Analysis (RCA) aims to determine the aetiology of adverse incidents that lead to patient harm and produce a series of recommendations, which would minimise the risk of recurrence of similar events, if appropriately applied to clinical practice. A review of the quality of the adverse incident reporting system and the RCA of serious adverse incidents at the Department of Surgery of Ninewells hospital, in Dundee, United Kingdom was performed.MethodsThe Adverse Incident Management (AIM) database of the Department of Surgery of Ninewells Hospital was retrospectively reviewed. Details of all serious (red, sentinel) incidents recorded between May 2004 and December 2009, including the RCA reports and outcomes, where applicable, were reviewed. Additional related information was gathered by interviewing the involved members of staff.ResultsThe total number of reported surgical incidents was 3142, of which 81 (2.58%) cases had been reported as red or sentinel. 19 of the 81 incidents (23.4%) had been inappropriately reported as red. In 31 reports (38.2%) vital information with regards to the details of the adverse incidents had not been recorded. In 12 cases (14.8%) the description of incidents was of poor quality. RCA was performed for 47 cases (58%) and only 12 cases (15%) received recommendations aiming to improve clinical practice.ConclusionThe results of our study demonstrate the need for improvement in the quality of incident reporting. There are enormous benefits to be gained by this time and resource consuming process, however appropriate staff training on the use of this system is a pre-requisite. Furthermore, sufficient support and resources are required for the implementation of RCA recommendations in clinical practice.

Cardiovascular autonomic function in patients with hemodynamic instability at induction of capnoperitoneum: a case–control study

BackgroundThis study hypothesized that patients in whom bradycardia and hypotension develop with induction of positive-pressure capnoperitoneum have an underlying autonomic cardiovascular dysfunction.MethodsA case–control study was conducted to examine the baseline autonomic function of patients in whom bradycardia and hypotension develop with induction of positive-pressure capnoperitoneum. The control group consisted of patients who maintained normal cardiac rhythm and blood pressure during the same procedure. Two groups of tests were performed: bedside stress tests of cardiovascular autonomic function (response graded 1 (normal) to 4 (severely abnormal) and heart rate variability analysis (spectral and time domain components).ResultsThe study evaluated 6 patients in the bradycardia group and 10 in the control group. The group in whom bradycardia had developed scored significantly worse on the bedside stress tests than the control group (for grades I to IV: χ2 = 6.5, p = 0.022; for trend: χ2 = 5.6, p = 0.018). In contrast, both groups had similar baseline autonomic tone, as measured by heart rate variability.ConclusionsPatients in whom bradycardia and hypotension develop with induction of positive-pressure capnoperitoneum have cardiovascular autonomic dysfunction, which is identifiable by bedside stress tests of autonomic function.

Mesenteric lipoma causing small bowel perforation: a case report and review of literature

A lipoma of the small bowel mesentery is a rare pathological entity. It has been shown to rarely cause obstruction and volvulus of the small bowel. We report a case of a 72-year-old man who presented with lower abdominal pain and slightly raised inflammatory markers. Computerized tomography of the abdomen showed small bowel perforation and oedematous terminal ileum. At laparotomy the cause was found to be a mesenteric lipoma causing small bowel perforation. As far as the authors are aware, this presentation is not described in the English language literature.

The effect of a simple intraprocedural checklist on the task performance of laparoscopic novices

BACKGROUND Surgical checklists are used for error reduction. Checklists are infrequently applied during procedures and have been limited to lists of procedural steps as aid memoires. We aimed to study the effect of a self-administered checklist on the laparoscopic task performance of novices during a standardized task. METHODS Twenty novices were randomized into 2 equal groups, those receiving paper feedback (control group) and those receiving paper feedback and the checklist (checklist group). Subjects performed laparoscopic double knots, repeated over 5 separate stages. Human reliability assessment technique was used for error analysis. RESULTS 2,341 errors were detected during the 5 stages. During the first stage, the errors were not significantly different between the 2 groups. The checklist group committed significantly fewer errors as compared with the control group during all the later 4 stages (P < .01). CONCLUSIONS The simple intraprocedural checklist significantly improved the laparoscopic task performance and the learning curve of laparoscopic novices.