Comparison of bipolar electrosurgical devices with ligatures and endoclips in the rat appendicitis model

Effectiveness of nonsurgical antibiotic treatment in the experimental appendicitis model in rats

Background

In this study, we aimed to demonstrate efficacy and laboratory follow-up criteria of nonsurgical antibiotic treatment in uncomplicated acute appendicitis. We established an experimental appendicitis model in rats, and antibiotic treatment was evaluated by biochemical and immunohistochemical changes.

Materials and method

In the study, 28 rats were divided into 4 groups. Group 1 constituted the group of sham; group 2 was the control group that appendicitis model was created and did not receive any treatment. Group 3 was created as an appendicitis model and was given regular antibiotic treatment. In group 4, appendicitis model was created, and appendectomy was performed on the 2nd day. Blood samples were taken from the rats on the 0, 2nd, and 7th days in all groups. Rats in groups 1, 2, and 3 underwent appendectomy with laparotomy under anesthesia on the 7th day. Serum C-reactive protein (CRP), procalcitonin, and leukocyte levels were measured for biochemical analysis. In immunohistochemical evaluation, inflammation severity of the tissue samples taken from appendices was evaluated. Also, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) levels of tissue samples were evaluated.

Results

A statistically significant difference in CRP values was observed between groups 1 and 2 on the 7th day (p = 0.046), between groups 1 and 4 on 0 and 2nd days (p = 0.004, p = 0.004), between groups 2 and 3 on 0, 2nd, and 7th days (p = 0.018, 0.013, 0.025), between groups 2 and 4 on 0, 2nd, and 7th days (p = 0.002, p = 0.002, p = 0.009), and between groups 3 and 4 on 0 and 2nd days (p = 0.013, p = 0.025). There was a significant difference in procalcitonin values between groups 1 and 3 on the 7th day (p = 0.032) and between groups 1 and 4 on day 0 (p = 0.019). A significant difference was also observed in TNF-α and IL-6 inflammation between groups 2 and 3 (p = 0.031, p = 0.018) and between groups 2 and 4 (p = 0.031, p = 0.01).

Conclusion

Acute uncomplicated and early appendicitis may be treated with antibiotics. According to our results, CRP levels are useful as follow-up criterion in experimental appendicitis model. Clinical studies on the assessment of CRP levels in the course of nonsurgical treatment in the patients with acute appendicitis will reveal out the effectiveness of this marker.

Potential therapeutic effects of ethyl pyruvate in an experimental rat appendicitis model

BACKGROUND

Pathophysiology of appendicitis is associated with the underlying inflammatory processes. Ethyl pyruvate (EP) has potent antioxidant and anti inflammatory properties. In this study, we aimed to investigate the effects of EP on the treatment of appendicitis and to examine whether adding EP to the antibiotic treatment could increases the effectiveness of the treatment in a rat appendicitis model.

METHOD

Thirty two Wistar rats, which had previously created appendicitis, were randomly divided into 4 groups: Group 1 (0.1 ml saline solution), Group 2 (15 mg/kg ceftriaxone), Group 3 (50 mg/kg EP), Group 4 (EP 50 mg/kg + ceftriaxone 15 mg/kg). In all groups, saline solution, ceftriaxone and EP were administered intraperitoneally and the same procedure was repeated twice a day for the following five days. On day 6, the rats underwent relaparotomy and then intraabdominal findings were recorded. Histopathological examination and interleukin 6 (IL 6) level were performed on appendiceal specimens.

RESULTS

Intra abdominal adhesion score was significantly lower in Group 4 than in Group 1. Total inflammation score was significantly lower in Group 2 than in Group 1 and was significantly lower in Group 4 than in Group 3 and 1. IL 6 level was significantly lower in Group 4 than in Group 3 and 1.

CONCLUSION

We found that adding EP to the antibiotic therapy increased the efficacy of the treatment in the rat appendicitis model. Further studies are required to apply our findings to the clinical setting.

Ex-Vivo Evaluation of "First Tip Closing" Radiofrequency Vessel Sealing Devices for Swine Small Intestinal Transection

This study compared burst pressure (BP), number of activations, and histological assessment of ex vivo swine small intestine loops transected by stapler, a single fulcrum radiofrequency vessel sealing (RFVS) device, and the newly-developed jaws RFVS. Fifty (n = 50) 20 cm long jejunal loops were randomly assigned to be transected with RFVS devices and linear stapler (Caiman5, Caiman Maryland, Caiman12, Ligasure Atlas, and Stapler group as control respectively). Caiman5, Caiman12 and stapler required only one activation to complete the sealing. The mean BP in Caiman5 and Caiman Maryland groups were significantly lower (p < 0.05) than the S group as control and the other RFVS devices studied. RFVS Caiman12 and Ligasure Atlas produced mean BP values that were close to the Control and did not differ between them. The lumen was totally closed in the Caiman12 and Ligasure Atlas groups. The findings of this investigation were promising; we discovered that Caiman12 and Ligasure Atlas produce comparable mechanical capabilities as well as stapled intestinal closure, however Caiman12 need a single activation to complete the transection.

Swine Small Intestine Sealing Performed by Different Vessel Sealing Devices: Ex-Vivo Test

This study aimed to evaluate the sealing quality of swine small intestine using different laparoscopic radiofrequency vessel sealing devices (two 5 mm: RFVS-1 and -2; one 10 mm: RFVS-3) and a harmonic scalpel (HS) compared to golden standard closure technique. The study was divided into two arms. In study arm 1: n = 50 swine intestinal loops (10 per group) were transected with each instrument and the loops in which the devices provided complete sealing, at the gross inspection, were tested for maximum burst pressure (BP) and histological evaluation and compared to an automatic linear stapler. After the BP tests, the devices that achieved significantly lower BP values were excluded from the second arm. The RFVS-1 and -3 provided statistically significant results and were used in study arm 2, to obtain full-thickness biopsies along the antimesenteric border of the loop and were compared with hand-sewn intestinal closure (n = 30; 10 per group). The biopsies were histologically evaluated for thermal injury and diagnostic features, and intestinal loops tested for BP. RFVS-3 achieved comparable results (69.78 ± 4.23 mmHg, interquartile range (IQR) 5.8) to stapler closing technique (71.09 ± 4.22 mmHg, IQR 4.38; p > 0.05), while the RFVS-1 resulted in significantly (p < 0.05) lower BP (45.28 ± 15.23 mmHg, IQR 24.95) but over the physiological range, conversely to RFVS-2 (20.16 ± 7.19 mmHg, IQR 12.02) and HS (not measurable). RFVS-3 resulted not significantly different (p > 0.05) (45.09 ± 8.75 mmHg, IQR 10.48) than Suture (35.71 ± 17.51 mmHg, IQR 23.77); RFVS-1 resulted significantly lower values (23.96 ± 10.63 mmHg, IQR 9.62; p < 0.05). All biopsies were judged diagnostic. Data confirmed that RFVS-1 and -3 devices provided suitable intestinal sealing, with BP pressures over the physiological range. Conversely, the HS and RFVS-2 should not be considered for intestinal sealing. RFVS devices could be employed to obtain small intestine stump closure or full-thickness biopsies. However, further studies should be performed in live animals to assess the role of the healing process.

Cecal Resection with Bipolar Sealing Devices in a Rat Model

Background: Bipolar sealing devices are routinely used to seal blood vessels. The aim of the study is to evaluate the feasibility and safety of colonic sealing with the use of the bipolar energy devices in rats as model for experimental appendectomy. Methods: Seventy-five male Wistar rats underwent a cecal resection with four different bipolar sealing devices or a linear stapler. The harvesting procedure was performed immediately or at postoperative day (POD) 7. The sealing front bursting pressure (BP) was measured in both groups. At POD7, the resection line was clinically examined and the hydroxyproline (HDP) levels were determined. Hematoxylin and Eosin (H&E) staining was used for histopathological evaluation of the sealing front as well. Results: There was no mortality and no insufficiency. The BPs between the bipolar sealing devices showed no statistical differences. The early phase of the seal (POD 0) provides a low BP with an 30.8% increase until POD 7. The BPs in the stapler group showed significant better values. The hydroxyproline levels did not differ statistically between the groups. Histopathologically, there were more signs of ischemic necrosis in the stapler group than in the sealing devices groups. Conclusion: The resection and sealing of the cecum as an experimental appendectomy model with the use of bipolar energy devices proved feasible and safe in rats. The different energy devices in this study produce comparable results. To justify clinical practice in humans, several studies on the underlying mechanisms of early stage wound healing are needed.

The feasibility of bipolar tissue sealer for appendix stump closure

BACKGROUND

Appendiceal stump closure is a highly important step in laparoscopic appendectomy, especially for post-operative complications. The aim of this study is to compare the effects of suture ligation and bipolar tissue sealer techniques on burst pressure using flesh appendectomy specimens.

MATERIAL AND METHODS

Appendectomy specimens of 32 patients with grade I-II disease were included in the study. Perforated or necrotic appendices and specimens ineligible for pressure measurement were excluded from the study. Appendiceal stumps of 16 patients in group 1 were double-ligated with 2/0 polyglactin sutures, then appendectomy was performed between these sutures. In group 2, the management of the stump was performed through single ligation with polyglactin suture, followed by appendectomy using a bipolar tissue sealing device. Burst pressures were recorded for all specimens.

RESULTS

There were no differences between groups in terms of age and sex. There was no significant difference between the two groups in terms of burst pressure (p = 0.92). Also, no significant difference was found between groups in terms of localization of the perforation (p > 0.05).

CONCLUSION

Bipolar tissue sealer achieves safe stump closure with satisfactory burst pressure values. Based on this, using bipolar tissue sealer for appendiceal stump closure in appendicitis may be safe and reliable.

Comparison and efficacy of LigaSure and rubber band ligature in closing the inflamed cecal stump in a rat model of acute appendicitis

Safety of either LigaSure or rubber band in closing inflamed appendiceal stump in acute appendicitis has been less investigated. In this study, cecal ligation followed by resecting inflamed cecum was performed to mimic appendectomy in a rat model of acute appendicitis. Rats were sacrificed immediately (Group A) and 7 days (Group B) after cecal resection, respectively. The cecal stumps were closed by silk ligature (S), 5 mm LigaSure (L), or rubber band (R). Seven days after cecal resection, the LigaSure (BL) and silk subgroups (BS) had significantly less intra-abdominal adhesion and better laparotomy wound healing than rubber band subgroup (BR). The initial bursting pressure at cecal stump was comparable among the three methods; along with tissue healing process, both BL and BS provided a higher bursting pressure than BR 7 days after appendectomy. BL subgroup had more abundant hydroxyproline deposition than BS and BR subgroup. Furthermore, serum TNF-α in BR group kept persistently increasing along with time after cecal resection. Thus, the finding that LigaSure but not rubber band is safe in sealing off the inflamed cecal stump in rat model of acute appendicitis suggests the possibility of applying LigaSure for appendectomy via single port procedure or natural orifice transluminal endoscopic surgery (NOTES).

Development of a standardized laparoscopic caecum resection model to simulate laparoscopic appendectomy in rats

Background

Laparoscopic appendectomy (LA) has become one of the most common surgical procedures to date. To improve and standardize this technique further, cost-effective and reliable animal models are needed.

Methods

In a pilot study, 30 Wistar rats underwent laparoscopic caecum resection (as rats do not have an appendix vermiformis), to optimize the instrumental and surgical parameters. A subsequent test study was performed in another 30 rats to compare three different techniques for caecum resection and bowel closure.

Results

Bipolar coagulation led to an insufficiency of caecal stump closure in all operated rats (Group 1, n = 10). Endoloop ligation followed by bipolar coagulation and resection (Group 2, n = 10) or resection with a LigaSure™ device (Group 3, n = 10) resulted in sufficient caecal stump closure.

Conclusions

We developed a LA model enabling us to compare three different caecum resection techniques in rats. In conclusion, only endoloop closure followed by bipolar coagulation proved to be a secure and cost-effective surgical approach.