Annals of Surgical Innovation and Research - Latest Articles

Internal gallbladder drainage prevents development of acute cholecystitis in a pig model: a randomized study.

Daniel Kjaer — 2010-05-26T00:00:00Z

Background: Acute cholecystitis can be the result of retention of bile in the gallbladder with possible secondary infection and ischaemia. The aim of the present study was to investigate whether internal drainage of the gallbladder could protect against the development of acute cholecystitis in a pig model.Materials and methodsTwenty pigs were randomized to either internal drainage (drained) or not (undrained). Day 0 acute cholecystitis was induced by ligation of the cystic artery and duct together with inoculation of bacteria. Four days later the pigs were killed and the gallbladders were removed and histologically scored for the presence of cholecystitis. Bile and blood samples were collected for bacterial culturing and biochemical analyses. Results: The histological examination demonstrated statistical significant differences in acute cholecystitis development between groups, the degree of inflammation being highest in undrained pigs. There were no differences in bacterial cultures between the two groups. Conclusion: Internal drainage of the gallbladder protected against the development of acute cholecystitis in the present pig model. These findings support the theory that gallstone impaction of the cystic duct plays a crucial role as a pathogenetic mechanism in the development of acute cholecystitis and suggest that internal drainage may be a way to prevent and treat acute cholecystitis.

Robotics versus laparoscopy - an experimental study of the transfer effect in maiden users

Magnus Anderberg — 2010-04-06T00:00:00Z

Background: Robot-assisted laparoscopy (RL) is used in a wide range of operative interventions, but the advantage of this technique over conventional laparoscopy (CL) remains unclear. Studies comparing RL and CL are scarce. The present study was performed to test the hypothesis that maiden users master surgical tasks quicker with the robot-assisted laparoscopy technique than with the conventional laparoscopy technique. Methods: 20 subjects, with no prior surgical experience, performed three different surgical tasks in a standardized experimental setting, repeated four times with each of the RL and CL techniques. Speed and accuracy were measured. A cross-over technique was used to eliminate gender bias and the experience gained by carrying out the first part of the study. Results: The task "tie a knot" was performed faster with the RL technique than with CL. Furthermore, shorter operating times were observed when changing from CL to RL. There were no time differences for the tasks of grabbing the needle and continuous suturing between the two operating techniques. Gender did not influence the results. Conclusion: The more advanced task of tying a knot was performed faster using the RL technique than with CL. Simpler surgical interventions were performed equally fast with either technique. Technical skills acquired during the use of CL were transferred to the RL technique. The lack of tactile feedback in RL seemed to matter. There were no differences between males and females.

Vascular clamping in liver surgery: physiology, indications and techniques

Elie Chouillard — 2010-03-26T00:00:00Z

This article reviews the historical evolution of hepatic vascular clamping and their indications. The anatomic basis for partial and complete vascular clamping will be discussed, as will the rationales of continuous and intermittent vascular clamping.Specific techniques discussed and described include inflow clamping (Pringle maneuver, extra-hepatic selective clamping and intraglissonian clamping) and outflow clamping (total vascular exclusion, hepatic vascular exclusion with preservation of caval flow). The fundamental role of a low Central Venous Pressure during open and laparoscopic hepatectomy is described, as is the difference in their intra-operative measurements. The biological basis for ischemic preconditioning will be elucidated. Although the potential dangers of vascular clamping and the development of modern coagulation devices question the need for systemic clamping; the pre-operative factors and unforseen intra-operative events that mandate the use of hepatic vascular clamping will be highlighted.

A comparison of perioperative outcomes of Video-Assisted Thoracic Surgical (VATS) Lobectomy with open thoracotomy and lobectomy: Results of an analysis using propensity score based weighting

Walter Scott — 2010-03-22T00:00:00Z

Background: Randomized trials comparing VATS lobectomy to open lobectomy are of small size. We analyzed a case-control series using propensity score-weighting to adjust for important covariates in order to compare the clinical outcomes of the two techniques. Methods: We compared patients undergoing lobectomy for clinical stage I lung cancer (NSCLC) by either VATS or open (THOR) methods. Inverse probability of treatment weighted estimators, with weights derived from propensity scores, were used to adjust cohorts for determinants of perioperative morbidity and mortality including age, gender, preop FEV1, ASA class, and Charlson Comorbidity Index (CCI). Bootstrap methods provided standard errors. Endpoints were postoperative stay (LOS), chest tube duration, complications, and lymph node retrieval. Results: We analyzed 136 consecutive lobectomy patients. Operative mortality was 1/62 (1.6%) for THOR and 1/74 (1.4%) for VATS, P = 1.00. 5/74 (6.7%) VATS were converted to open procedures. Adjusted median LOS was 7 days (THOR) versus 4 days (VATS), P < 0.0001, HR = 0.33. Adjusted median chest tube duration (days) was 5 (THOR) versus 3 (VATS), P < 0.0001, HR = 0.42. Complication rates were 39% (THOR) versus 34% (VATS), P = 0.61. Adjusted mean number of lymph nodes dissected per patient was 18.1 (THOR) versus 14.8 (VATS), p = 0.17. Conclusions: After balancing covariates that affect morbidity, mortality and LOS in this case-control series using propensity-weighting, the results confirm that VATS lobectomy is associated with a statistically significant shorter LOS, similar mortality and complication rates and similar rates of lymph node removal in patients with clinical stage I NSCLC.

Microdialysis assessment of peripheral metabolism in critical limb ischemia after endovascular revascularization

Matteo Tozzi — 2009-12-31T00:00:00Z

Background: Critical limb ischemia is a chronic pathologic condition defined by the lack of blood flow in peripheral circulation. Microdialysis is a well-known and sensitive method for the early detection of tissue ischemia. The aim of the present study was to use microdialysis in order to analyse cellular metabolism changes after peripheral endovascular revascularization. Methods: Ten patients diagnosed with critical limb ischemia was enrolled. CMA 60 (CMA® - Solna, Sweden) catheter with a 20 kDa cut-off was placed subcutaneously on the anterior aspect of the foot of both limbs. Samples were collected starting 12-hours before surgery and throughout the following 72-hours, using a CMA 600 (CMA® - Solna, Sweden) microdialysis analyser. Results: Technical revascularization was successful in all cases. The cannulation was well tolerated in all patients. The site of catheter insertion healed easily in few days without infective complications in any case. Two patients underwent major amputation. After revascularization, glucose showed a strong increase (mean, 5.86 ± 1.52 mMol/L, p = .008). No restoration of the circadian rhythm was noted in patients who underwent major amputation. Glycerol concentration curves were not deductibles in both the ischemic and the control limbs (mean, 148.43 ± 42.13 mMol/L vs 178.44 ± 75.93 mMol/L, p = .348). Within the first 24-hours after revascularization, lactate concentration raised strongly (6.58 ± 1.56 mMol/L, p = .002): thereafter, it immediately decreased to a concentration similar to the control level (1.71 ± 1.69 mMol/L). In both patients who underwent major amputation, lactate did not show the typical peak of the successful revascularization. The trend of the lactate/pyruvate ratio after a brief initial decrease of the ratio increased again in both the patients who finally underwent amputation. Conclusions: Restoration of glucose and glycerol circadian rhythm, coupled with low lactate concentration and lactate/pyruvate ratio seemed to be linked to good surgical outcome.

Increased liver regeneration rate and decreased liver function after synchronous liver and colon resection in rats

Hideki Sasanuma — 2009-12-24T00:00:00Z

Background: The surgical strategy for the treatment of colorectal cancer and synchronous liver metastases remains controversial. The aim of the present study was to investigate the effects of colonic resection on liver function and regeneration in a rat model. Methods: Ninety-six Sprague-Dawley rats were block-randomized into six groups: Group I had a laparotomy performed. Group II had 1 cm colon resected and anastomosed. Group III and V had 40% or 70% of the liver resected, respectively. Additionally Group IV and VI had 1 cm colon resected and anastomosed, respectively. Body weight was recorded on postoperative day 0, 3, 5 and 7. Rats were sacrificed on postoperative day 7 by rapid collection of blood from the inferior vena cava, and endotoxin levels were measured. Remnant liver function was evaluated by means of branched amino acids to tyrosine ratio. Liver regeneration was calculated by (liver weight per 100 g of the body weight at sacrifice/preoperative projected liver weight per 100 g of the body weight) × 100. Results: The total number of complications was significantly higher in Group VI than Group I, III, IV, and V. Body weight and branched amino acids to tyrosine ratio were both significantly lower in rats that had simultaneous colonic and liver resection performed. Hepatic regeneration rate was significantly higher in the simultaneous colectomy group. Systemic endotoxin levels were unaffected by simultaneous colectomy on postoperative day 7. Conclusions: In our model morbidity seems to be related to the extent of hepatic resection. In rats undergoing liver resection, simultaneous colectomy induced a higher degree of hepatic regeneration rate. Body weight changes and branched amino acids to tyrosine ratio were negatively affected by simultaneous colectomy.

Emergency treatment of complicated incisional hernias: a case study

Francesco La Mura — 2009-12-17T00:00:00Z

Background: The emergency treatment of incisional hernias is infrequent but it can be complicated with strangulation or obstruction and in some cases the surgical approach may also include an intestinal resection with the possibility of peritoneal contamination. Our study aims at reporting our experience in the emergency treatment of complicated incisional hernias. Methods: Since January 1999 till July 2008, 89 patients (55 males and 34 females) were treated for complicated incisional hernias in emergency. The patients were divided in two groups: Group I consisting of 33 patients that were treated with prosthesis apposition and Group II, consisting of 56 patients that were treated by performing a direct abdominal wall muscles suture. Results: All the patients underwent a 6-month follow up; we noticed 9 recurrences (9/56, 16%) in the patients treated with direct abdominal wall muscles suture and 1 recurrence (1/33, 3%) in the group of patients treated with the prosthesis apposition. Conclusions: According to our experience, the emergency treatment of complicated incisional hernias through prosthesis apposition is always feasible and ensures less post-operative complications (16% vs 21,2%) and recurrences (3% vs 16%) compared to the patients treated with direct muscular suture.

Topical recombinant thrombin at a concentration of 1000 IU/mL reliably shortens in vivo TTH and delivers durable hemostasis in the presence of heparin anticoagulation and clopidogrel platelet inhibition in a rabbit model of vascular bleeding

Steven Hughes — 2009-11-19T00:00:00Z

Background: This study was designed to evaluate the effect of recombinant human thrombin (rThrombin) concentration on time to hemostasis (TTH), clot durability, and clot strength in settings that replicate the heparinization and platelet inhibition often found in surgical populations. Methods: A modified, anticoagulated rabbit arteriovenous shunt preparation was selected to model vascular anastomotic bleeding. Rabbits were treated with heparin or heparin + clopidogrel and TTH was measured after applying a range of topical rThrombin concentrations or placebo, in combination with absorbable gelatin sponge, USP. Treatments (placebo, rThrombin) were randomly assigned and the investigator was blinded to treatment. TTH was evaluated with the Kaplan-Meier method. After hemostasis was achieved, clot burst assessment was performed for heparin + clopidogrel treated animals. Clot viscoelastic strength and kinetics were measured in ex-vivo samples using thromboelastography (TEG) methods. Results: TTH decreased with increasing concentrations of rThrombin in heparin-treated animals and was shorter after treatment with 1000 IU/mL rThrombin (73 seconds) than with 125 IU/mL rThrombin (78 seconds; p = 0.007). TTH also decreased with increasing concentrations of rThrombin in heparin + clopidogrel treated animals; again it was significantly shorter after treatment with 1000 IU/mL rThrombin (71 seconds) than with 125 IU/mL rThrombin (177 seconds; p < 0.001). Variability in TTH was significantly smaller after treatment with 1000 IU/mL rThrombin than after 125 IU/mL rThrombin, indicating greater reliability of clot formation (p < 0.001 for heparin or heparin + clopidogrel treatments). Clot durability was examined in heparin + clopidogrel treated animals. Clots formed in the presence of 1000 IU/mL rThrombin were significantly less likely to rupture during clot burst assessment than those formed in the presence of 125 IU/mL rThrombin (0% versus 79%, p < 0.001). In vitro clot strength and clot kinetics, as determined by TEG in heparin + clopidogrel samples, were positively associated with the amount of rThrombin activity added for clot initiation. Conclusion: In an animal model designed to replicate the anti-coagulation regimens encountered in clinical settings, topical rThrombin at 1000 IU/mL more reliably controlled the pharmacological effects of heparin or heparin + clopidogrel on hemostasis than rThrombin at 125 IU/mL. Results from in vitro assessments confirmed a positive relationship between the amount of rThrombin activity and both the rate of clot formation and clot strength.

Expression of TNF-related apoptosis-inducing ligand (TRAIL) in keratinocytes mediates apoptotic cell death in allogenic T cells

Kerstin Reimers — 2009-11-19T00:00:00Z

The objective of the present study was to evaluate the aptitude of TRAIL gene expression for inducing apoptosis in co-cultivated T-cells. This should allow preparing a strategy for the development of a durable, allogenic skin substitute based on the induction of an immune-privileged transplant. In order to counteract the significant potential of rejection in transplanted allogenic keratinocytes, we created a murine keratinocyte cell line which expressed TRAIL through stable gene transfer. The exogenic protein was localized on the cellular surface and was not found in soluble condition as sTRAIL. Contact to TRAIL expressing cells in co-culture induced cell death in sensitive Jurkat-cells, which was further intensified by lymphocyte activation. This cytotoxic effect is due to the induction of apoptosis. We therefore assume that the de-novo expression of TRAIL in keratinocytes can trigger apoptosis in activated lymphocytes and thus prevent the rejection of keratinocytes in allogenic, immune-privileged transplants.

Fibrin glue in the treatment of anal fistula: a systematic review

Roberto Cirocchi — 2009-11-14T00:00:00Z

Background: New sphincter-saving approaches have been applied in the treatment of perianal fistula in order to avoid the risk of fecal incontinence. Among them, the fibrin glue technique is popular because of its simplicity and repeatability. The aim of this review is to compare the fibrin glue application to surgery alone, considering the healing and complication rates. Methods: We performed a systematic review searching for published randomized and controlled clinical trials without any language restriction by using electronic databases. All these studies were assessed as to whether they compared conventional surgical treatment versus fibrin glue treatment in patients with anal fistulas, in order to establish both the efficacy and safety of each treatment. We used Review Manager 5 to conduct the review. Results: The healing rate is higher in those patients who underwent the conventional surgical treatment (P = 0,68), although the treatment with fibrin glue gives no evidence of anal incontinence (P = 0,08). Furthermore two subgroup analyses were performed: fibrin glue in combination with intra-adhesive antibiotics versus fibrin glue alone and anal fistula plug versus fibrin glue. In the first subgroup there were not differences in healing (P = 0,65). Whereas in the second subgroup analysis the healing rate is statistically significant for the patients who underwent the anal fistula plug treatment instead of the fibrin glue treatment (P = 0,02). Conclusion: In literature there are only two randomized controlled trials comparing the conventional surgical management versus the fibrin glue treatment in patients with anal fistulas. Although from our statistical analysis we cannot find any statistically significant result, the healing rate remains higher in patients who underwent the conventional surgical treatment (P = 0,68), and the anal incontinence rate is very low in the fibrin glue treatment group (P = 0,08). Anyway the limited collected data do not support the use of fibrin glue. Moreover, in our subgroup analysis the use of fibrin glue in combination with intra-adhesive antibiotics does not improve the healing rate (P = 0.65), whereas the anal fistula plug treatment compared to the fibrin glue treatment shows good results (P = 0,02), although the poor number of patients treated does not lead to any statistically evident conclusion. This systematic review underlines the need of new RCTs upon this issue.