Postoperative adhesion formation after laparoscopic uterine horn resection in a porcine model: comparison of five instruments

PURPOSE: To evaluate the postoperative adhesion formation caused by instruments used in gynecologic laparoscopic surgery and to determine the optimal instruments to use to reduce adhesions. MATERIALS AND METHODS: Seventeen juvenile pigs underwent laparoscopic bilateral resection of the uterine horns under general anesthesia and pneumoperitoneum. The laparoscopic procedures were carried out using monopolar electrocautery (ME) (n = 8), an electrothermal bipolar vessel sealer (EBVS) (n = 6), an ultrasonically activated scalpel (UAS) (n = 6), a loop-type ligature (LTL) with a steel scalpel for severing the tissues (n = 6), and an automatic stapling device (ASD) (n = 8). Second- look laparotomy was performed 14 days postoperatively, and the degree of postoperative adhesions was scored from 0 to 6. RESULTS: The mean and range of adhesion scores were 0.00 with EBVS, 0.13 (range, 0-1) with ASD, 0.33 (range, 0-2) with LTL, 1.17 (range, 0-3) with UAS, and 3.13 (range, 2-6) with ME. We found a statistically significant difference in the extent of postoperative adhesion formation associated with these 5 instruments (P < 0.001, Kruskal-Wallis test). CONCLUSION: Adhesion formation increased in the order EBVS < ASD < LTL < UAS < ME. Our study strongly suggests that surgical instruments can be selected to reduce postoperative adhesion formation, a particular concern in women of reproductive age.     

Pure transvesical NOTES uterine horn resection in swine as an appendectomy model

Background

Because of size limitation, the lack of reliable instruments, and bladder closure methods, transvesical natural orifice translumenal endoscopic surgery (NOTES) is still in its infancy. The porcine uterine horn is similar to the human vermiform appendix. Therefore, the resection of the porcine uterine horn is an established animal model for the human appendectomy. In this study, we evaluated the feasibility of a pure transvesical NOTES approach to uterine horn resection in a porcine model.

Methods

We performed five operations on three female pigs (30?C35?kg) under general anesthesia in the Trendelenburg position. The laparoscope at the umbilicus was used only for the purpose of documentation. We used a rigid ureteroscope and a customized access system that prevented gas leakage and facilitated in-and-out passage of the instruments. A vesicostomy was created on the posterolateral bladder wall by using a needle knife through the channel of the ureteroscope. The uterine horn resection was performed by using an electric needle knife, hot forceps, and a polypectomy snare through the access system placed in vesicostomy. Bladder closure was performed with extracorporeal ties using metal clip tagged threads and a knot-pusher.

Results

We successfully performed the pure transvesical NOTES uterine horn resections. The mean total operative time was 141.8 (±58.7) min, and blood loss was minimal in all cases. No leakage was observed at the bladder repair sites after filling with normal saline. The removed uterine horns were approximately 6?C12-cm long and 0.6?C0.8?cm in diameter. On final inspection, the urethras were not damaged.

Conclusions

This study demonstrates the feasibility of a pure transvesical NOTES uterine horn resection in a porcine model. To the best of our knowledge, this is the world??s first report on a pure transvesical NOTES with a therapeutic purpose. This study shows the potential for adoption of the transvesical approach in NOTES procedures.     

腹腔镜与开腹胆总管切开取石术应激反应差异分析

目的比较两种手术术式应用于结石患者治疗时应激反应差异。方法选取胆总管结石患者80名,随机分为腹腔镜组和开腹组,每组40例,均接受胆囊切除术和胆总管切开取石术;应用SPSS 20.0软件包进行数据处理,术中出血量、手术时间、术后胃肠道功能恢复时间、术后住院时间、Cor、C-P、FT3水平等计量资料以(x珋±s)表示,采用t检验;不良反应发生率等计数资料采用χ2检验,P0.05为差异具有统计学意义。结果腹腔镜组患者术中出血量、肠道功能恢复时间和住院时间显著低于开腹组(t=12.019,t=6.757,t=10.343,P0.01)。腹腔镜组患者术后3 d内血清皮质醇(Cor)、C-肽(C-P)和游离三碘甲状腺原氨酸(FT3)水平显著优于开腹组(t=6.296,t=11.030,t=7.408,P0.01)。腹腔镜组患者术后并发症发生率显著低于开腹组(χ2=15.313,P0.01)。结论腹腔镜胆总管切开取石术术中损伤小、术后恢复快患者应激反应小并发症发生率低,具有临床应用价值。     

Systemic and cell-specific immune response to laparoscopic and open nephrectomy in porcine model

PURPOSE: To determine differences in the systemic and cell-specific immune response to open and laparoscopic nephrectomy in the porcine model. MATERIALS AND METHODS: Twenty male pigs (25-40 kg) were vaccinated with human adenovirus containing ovalbumin (Ova) and 3 weeks later underwent a sham procedure (N = 4), laparoscopic nephrectomy (LN)(N = 8), or open nephrectomy (ON) (N = 8). Blood was collected after anesthesia induction and immediately and 24 and 48 hours postoperatively and assayed for complete blood count (CBC), cortisol, and C-reactive protein (CRP). Natural killer (NK) cells were isolated and stimulated in vitro for 48 hours with polyinosinic:polycytidylic acid (Poly I:C) and interleukin (IL)-2 to determine cytotoxic activity. Peripheral blood mononuclear cells (PBMC) were isolated for flow cytometry staining with CD8, CD4, and CD25 markers. Additional PBMCs were stimulated in vitro with Ova and ConA for 48 hours to measure the production of IL-10 and interferon (IFN)-gamma and a thymidine-incorporation assay to determine T-cell proliferation. RESULTS: One animal in the ON group had signs of infection preoperatively and was removed from analysis. The LN took significantly longer than ON or sham nephrectomy (P = 0.002). Blood loss and animal weight were similar in the three groups. The CRP concentration increased more in the ON than the LN and sham-treatment groups in the first 48 hours (P = 0.01). No statistical differences were seen in the elevation of white blood cells or cortisol concentration. All groups demonstrated a decrease in the cytotoxic activity of NK cells postoperatively, with a significantly greater decrease in the sham-treated animals (P = 0.004). The LN group demonstrated greater T-cell activation than the ON and sham-treatment groups with both CD4(+) (P = 0.002) and CD8(+) (P = 0.028) cells increasing their expression of the activation marker CD25. The thymidine-incorporation assay demonstrated decreased T-cell proliferation in the ON group when stimulated with ConA (P = 0.014). Production of IL-10 decreased in the sham-treated and LN animals while increasing after ON. There was no difference in IFN-gamma among the groups. CONCLUSIONS: In a porcine model, ON produces higher CRP concentrations postoperatively, a larger decrease in T-cell proliferation ability, and more IL-10 activity than LN or sham treatment. Animals undergoing LN demonstrated greater T-cell activation postoperatively. White blood cell counts, serum cortisol concentration, and production of IFN-gamma were similar among the groups. These findings suggest ON causes greater immune suppression than LN in the porcine model.     

Evaluation of serum cytokine release in response to hand-assisted, laparoscopic, and open surgery in a porcine model

Background

Although the immunologic benefits of laparoscopic surgery have been established, effects from hand-assisted (HA) surgery have not been investigated thoroughly. We hypothesized that the HA approach maintains the immunologic advantage of laparoscopic surgery compared with the open (O) approach.

Methods

Six O, HA, and laparoscopic (L) transabdominal left nephrectomies were performed on pigs. Blood samples were taken preoperatively, perioperatively, and postoperatively, and serum interleukin-6 and C-reactive protein levels were measured.

Results

At 24 hours after surgery, interleukin-6 levels were significantly higher in the O group vs the HA and L groups (82.2 vs 37.5 and 29.9 pg/mL, respectively; P < .05). Similar trends were seen at all time periods for both IL-6 and C-reactive protein. No significant differences in postoperative cytokine levels were detected between the HA and L groups.

Conclusions

The HA approach mimics the immunologic effects of laparoscopic surgery. These data suggest that the HA technique resulted in a reduced systemic immune activation in the early perioperative period when compared with open surgery. In addition to clinical benefits of minimal access, the HA approach also may afford patients an immunologic advantage over laparotomy.     

Comparative evaluation of gastrointestinal transit and immune response between laparoscopic and open gastrectomy in a porcine model

Several reports have shown advantages of laparoscopic gastrointestinal (GI) procedures when compared with their open counterparts. The aim of this study was to assess the differences of GI transit and immune response between laparoscopic and open gastrectomy in a porcine model. Fourteen pigs were assigned to undergo partial gastrectomy, either by laparoscopy (lap group) or by laparotomy (open group). GI transit was assessed using 24 markers and measured until half of markers were evacuated. To assess immune response, we used delayed-type hypersensitivity skin antigen testing (DTH) with vaccine antigen. DTH was evaluated at 48 hours after the primary injection for induration. After 2 weeks, all animals underwent necropsy and were evaluated for adhesion formation using a scoring scale. Operation time was significantly longer in the lap group. The GI transit in the postoperative phase was significantly prolonged compared with the preoperative measured times. Postoperatively, the GI transit in the open group was significantly prolonged compared with the lap group. Immune response measured by DTH was better preserved in the lap group than in the open group. Adhesion formation was significantly less in the lap group. We concluded that laparoscopic gastrectomy resulted in faster bowel recovery and less immune suppression. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 15–18, 2005 (poster presentation).     

Controlled trial of laparoscopic-assisted vs open colon resection in a porcine model

Background: Several series of laparoscopic colon resection have been reported in the literature with varied results; however, no controlled series of laparoscopic vs open colon resection has been reported. The purpose of this study was to determine the relative safety and adequacy of laparoscopic colon resection in a controlled trial using a porcine model. Methods: Domestic pigs (n=23) were randomly divided into two groups. Animals underwent either an open or laparoscopic-assisted segmental resection of the sigmoid colon. The open resections were performed through a 20-cm midline incision and the laparoscopic technique utilized five 12-mm ports. Laparoscopic resection took twice as long to complete as open resection (P<0.001). Return of gastric function was significantly faster in the laparoscopic group than in the open group (P<0.032). Results: No significant differences were found in total length of resection, proximal or distal margins, number of lymph nodes recovered, length of mesenteric vessel resected, or time to return of bowel function. At vivisection, more adhesions to the abdominal wall were noted in the open group (P<0.002). One death occurred in the laparoscopic group 2 h postoperatively (8.3% mortality) while all open group pigs survived. However, there was no statistically significant difference in mortality rates by chi-square analysis (P>0.5). Conclusions: Despite longer operative time, laparoscopic intervention is technically feasible, safe, and may offer significant postoperative benefits due to fewer abdominal adhesions.     

Gut oxygenation and oxidative damage during and after laparoscopic and open left-sided colon resection: a prospective, randomized, controlled clinical trial

Background  

Pneumoperitoneum (PP), established for laparoscopic (LPS) operation, has been associated with potential detrimental effects, such as mesenteric ischemia–reperfusion injury. The objective of the trial was to measure intestinal tissue oxygen pressure (P_tiO₂) and oxidative damage during laparoscopic (LPS) and open colon surgery and during the postoperative course.     

Inflammatory response in children after laparoscopic vs open Nissen fundoplication: randomized controlled trial

We performed a randomized controlled trial to compare the inflammatory and immune responses to Nissen fundoplication in infants and children undergoing either open or laparoscopic surgery.

Methods

Forty children undergoing Nissen fundoplication were randomized to laparoscopy or open surgery using minimization with respect to age, neurologic status, and operating surgeon. Intraoperative and postoperative analgesias were standardized. Inflammatory markers (plasma malondialdehyde, nitrate plus nitrite level, and cytokines) and monocyte class II major histocompatibility complex expression were measured preoperatively, at end of surgery, 4, 24, and 48 hours postoperatively. Postoperative changes were compared between open and laparoscopic groups.

Results

There were no significant changes in circulating malondialdehyde, nitrates plus/ nitrite, interleukin-10, or tumor necrosis factor α in the postoperative period in either group. Interleukin-1 receptor antagonist (IL-1rA) and IL-6 were significantly increased in both groups, with a tendency for greater elevation of IL-1rA in the open group. Monocyte major histocompatibility complex expression fell significantly in both groups; however, this fall appeared to be slightly more marked in the open group.

Conclusions

The postoperative cytokine response is similar in children undergoing open and laparoscopic Nissen fundoplication. This trial indicates that laparoscopy may partly reduce postoperative immune suppression.     

Prospective randomized study of stress and immune response after laparoscopic vs conventional colonic resection

Methods: In order to evaluate the stress and immunological response to laparoscopic and conventional colon resection we operated on male Wistar rats (350–380 g), performing either laparoscopic (n= 15) or open colon resection (n= 15). A third group (n= 10) underwent anesthesia only. Immediately before and after surgery as well as 1 and 7 days postoperatively a 1 ml sample of blood was taken from the retrobulbar veinous plexus. Stress (corticosterone) and immune parameters (neopterin and interleukin [IL] 1-β) were measured. Furthermore, the body weight as a parameter of postoperative recovery was monitored. Results: The analysis of variance showed significant differences between the three groups over a period of 1 week (p < 0.0001 for corticosterone, p= 0.0854 for IL 1-β, p= 0.0045 for neopterin). Additionally in a t-test significant differences were found between the laparoscopic and conventional group with regard to corticosterone (p= 0.08), to neopterin (p= 0.045), and to IL 1-β (p= 0.0043) at the end of the operation. One week after the operation the stress and immune parameters were back to normal levels in each group except IL 1-β, but the recovery indicated by body weight was different according to the kind of the applied operative procedure: 7 days postoperatively the rats lost 5.99% of their body weight after open surgery and only 2.4% after laparoscopic surgery. After anesthesia only the body weight increased by about 4.8%. Conclusion: Laparoscopic colon resection alters the stress and immune system of healthy rats less than open colon resection. This observation is confirmed by the quicker recovery in laparoscopically operated rats.     

COLOR: a randomized clinical trial comparing laparoscopic and open resection for colon cancer

BACKGROUND: Laparoscopic surgery has proven to be safe and effective. However, the value of laparoscopic resection for malignancy in terms of cancer outcome can only be assessed by large prospective randomized clinical trials with sufficient follow-up. METHODS: COLOR (COlon carcinoma Laparoscopic or Open Resection) is a European multicenter randomized trial that began in 1997. In 27 hospitals in Sweden, The Netherlands, Germany, France, Italy, Spain, and the United Kingdom, 1200 patients will be included. The primary endpoint of the study is cancer-free survival after 3 years. RESULTS: In <3.5 YEARS, >850 patients have been randomized for right hemicolectomy (47%), left hemicolectomy (11%), and sigmoidectomy (42%). Fifty seven patients were excluded after randomization. Forty six months after the start of the trial, the overall recurrence rate is 6.8%. The distribution of stage of disease is as follows: stage I, 25%; stage II, 41%; stage III, 32%; stage IV, 2%. CONCLUSION: Although laparoscopic surgery appears to be of value in the treatment of colorectal cancer, the final, results of randomized trials need to be considered to determine its definitive role. Given the current accrual rate, the COLOR study will be completed in 2002.     

Systemic acute-phase response after laparoscopic and open cholecystectomy

BACKGROUND: Cytokines are the main mediators of inflammation and the response to trauma. The purpose of this study was to compare variations in cytokine levels following laparoscopic cholecystectomy (LC) and mini-laparotomy cholecystectomy (OC), since these two types of operations were considered to be a unique model for examining the role of local tissue injury in postoperative inflammatory reactions. METHODS: A total of 40 patients were studied. Eighteen of them underwent LC; the remaining 22 were operated on using the open technique. Systemic concentrations of interleukin-6 (IL-6), interleukin-1 (IL-1), tumor necrosis factor (TNF), and C-reactive protein (CRP) were measured before and after the operation. In addition, we compared pre- and postoperative white blood cell (WBC) counts, postoperative body temperature, and length of postoperative hospitalization. RESULTS: There was no difference between the two groups in IL-1 and TNF response. The rise in plasma IL-6 levels (18.86 +/- 9.61 vs 5.00 +/- 0.0 pg/ml, p < 0.0001) and CRP (8.40 +/- 5.81 vs 1.43 +/- 1.30 mg/dl, p < 0.001) were more marked after open cholecystectomy than after the laparoscopic procedure. There was no correlation between serum CRP concentrations and the other postoperative parameters. CONCLUSION: The magnitude of the acute-phase response was less pronounced following laparoscopic cholecystectomy, consistent with a reduction in tissue trauma.     

Systemic immune response after laparoscopic and open cholecystectomy

The laparoscopic approach is thought to reduce the postoperative immunologic and metabolic effects of an open operation. This study was designed with the aim of comparing the systemic immune response after laparoscopic and open cholecystectomy. Seventeen patients with gallbladder stones were assigned to undergo either a laparoscopic (n = 9) or open (n = 8) approach. The postoperative immune response was assessed by measuring the serum levels of soluble Fas (sFas), soluble L-selectin (sL-selectin), and transforming growth factor-beta1 (TGFbeta1) preoperatively and 2 hours, 1 day, and 2 days postoperatively. Both approaches resulted in a significant decrease in sFas levels 1 and 2 days postoperatively. The open approach evoked a transient increase in sL-selectin levels 2 hours postoperatively. Moreover, the open approach resulted in a persistent, significant increase in TGFbeta1 levels postoperatively. Comparison of open versus laparoscopic cholecystectomy has shown no significant difference in sFas level and a statistically significant increase of sL-selectin (within 2 hours) and TGFbeta levels after open surgery. Although both laparoscopic and open cholecystectomy evoked an alteration of the systemic immune response, our data showed that such immune response may be less after the laparoscopic approach.     

Coagulation modifications after laparoscopic and open cholecystectomy in a swine model

Background: The stress response to surgical trauma precipitates a state of transient hypercoagulation. Studies have demonstrated that laparoscopic surgery results in a diminished stress response compared to open surgery. The aim of this study was to determine the extent of postoperative hypercoagulability following laparoscopic cholecystectomy (LC) compared to open cholecystectomy (OC). Methods: Twenty-one pigs were randomly selected to undergo LC (N= 10) or OC (N= 11). Whole blood was collected preoperatively and on postoperative days (PODs) 1, 2, and 3 for determination of viscoelastic changes using a thromboelastography (TEG) coagulation analyzer. Four parameters were calculated from the TEG: R (reaction time), K (coagulation time), α (rate of clot formation), and MA (maximal amplitude). Antithrombin III (AT III) level was measured preoperatively and on POD 1. Results: After OC, three of four TEG parameters changed to reflect a state of hypercoagulation. Only MA values were significantly changed after LC. Comparison between OC and LC showed no difference in the TEG parameter. There was no significant change in AT III levels after LC or OC. Conclusions: OC results in postoperative hypercoagulation typically encountered in open abdominal surgery. Although there were no differences in TEG or AT III between the two groups, after the laparoscopic approach all but one TEG parameter remained unchanged, suggesting a diminished hypercoagulable state. By reducing postoperative hypercoagulation, laparoscopic surgery may reduce the risk of developing postoperative venous thrombosis.