Laparoscopic Splenectomy in a Rat Model: Developing an Easy Technique

Laparoscopic Pancreatectomy in Rats: The Development of an Experimental Model

INTRODUCTION

several pancreatectomy techniques in rats have been described and utilized for research concerning the pancreas endocrine and exocrine functions. However, we did not find a description of any kind of laparoscopic pancreatectomy in rats in the consulted databases. The objective of this study is to describe a laparoscopic splenic lobe pancreatectomy in rats.

METHODS

ten Wistars rats weighting more then 300 g were operated for standardizing the laparoscopic pancreatosplenectomy technique, aided by previous descriptions of laparoscopic splenectomy and open pancreatectomy in rats. Adjustments have been progressively adopted for technical refinement.

RESULTS

In five animals a low-cost rat laparoscopic set was used. In other five animals we used a standard laparoscopic set. Three rats died early due to different causes: transection of the gastroesophageal junction, hemorrhagic shock and inadvertent colonic injury. The postoperative period of the other seven rats was uneventful until the seventh postoperative day.

DISCUSSION

laparoscopic distal pancreatectomy and splenectomy in rats is feasible and safe, even with a low-cost set, in which the results were alike the standard laparoscopic set.

Exotic Mammal Laparoscopy

Laparoscopy is an evolving field in veterinary medicine, and there is an increased interest in using laparoscopic techniques in nondomestic mammals, including zoo animals, wildlife, and exotic pets. The aim of this article is to summarize the approach to laparoscopic procedures, including instrumentation, patient selection and preparation, and surgical approaches, and to review the current literature on laparoscopy in exotic mammals.

Laparoscopic surgery in a rat model

BACKGROUND

The rat is increasingly being used in laparoscopic research. Laparoscopic microsurgical training is critical in order to develop new surgical indications in pediatric patients. This report evaluates laparoscopic splenectomy and nephrectomy in a rat model.

MATERIALS AND METHODS

A Wistar rat (weight between 250 and 400 g) was placed in the supine position. Inhaled 3% halothane anesthesia was administered. A Veress needle is inserted in the right-upper abdomen. After establishing a pneumoperitoneum of 3-4 mm Hg, a 2- or 5-mm trocar was placed, according to the procedure. A 2-mm 0-degree endoscope was used. Two additional 2- or 5-mm trocars were then placed. Laparoscopic splenectomy involved two-handed dissection, intracorporeal ligation, and the division of gastrosplenic attachments and hilar and short gastric vessels. Laparoscopic nephrectomy was done by intracorporeal ligation and division of the renal vessels and the ureter after mobilization of the kidney.

RESULTS

Laparoscopic splenectomy was performed in 8 rats; laparoscopic nephrectomy was done in 4 rats. Operative time was 25-40 minutes for splenectomy and from 30 to 65 for nephrectomy. Postoperatively, 4 rats died from hemorrhage. No wound infections occurred at the port sites.

CONCLUSIONS

Laparoscopic splenectomy and nephrectomy in an experimental rat model is technically feasible and may provide an excellent training model for pediatric minimally invasive surgery.

The role of the spleen in laparoscopy-associated inflammatory response

BACKGROUND

Carbon dioxide (CO(2)) pneumoperitoneum alters the inflammatory response in animal models of sepsis. The spleen is a key organ in inflammation and its removal was predicted to modify this effect.

METHODS

The acute phase inflammatory response to lipopolysaccharide (LPS) challenge in male rats was examined for the effects of splenectomy (spx) and the technique of removal (open or laparpscopic). A series of experiments compared LPS-only controls with LPS injection 2 or 9 days following open spx, lap CO2 spx, open sham, or lap CO2 sham. The method of splenectomy was studied by randomization to control, open spx, lap CO2 spx, lap helium (He) spx, or lap air spx with LPS challenge on postoperative day 2. Serum levels of tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (INF-gamma) and, interleutin (IL) 10 were collected at multiple time points, assayed by commercial enzyme-linked immunosorbent assay, analyzed by analysis of variance.

RESULTS

Levels of TNF-alpha at 1.5 were significantly lower following open sham than following lap sham (p < 0.05). Splenectomy drastically reduced INF-gamma and TNF-alpha levels compared to controls (p < 0.05) on postoperative day 2. No method of spx preserved TNF-alpha or INF-gamma responses. Recovery of TNF-alpha response on day 9 was delayed in the spx groups.

CONCLUSIONS

Splenectomy dramatically reduces TNF-alpha and INF-gamma responses to LPS challenge, although by different mechanisms. Pneumoperitoneum-mediated modulation of the septic inflammatory response is partially dependent on the spleen.

Evaluation of risk of splenosis during laparoscopic splenectomy in rat model

Laparoscopic splenectomy (LS) is an alternative to open surgery. However, there is a theoretic risk of splenosis and abdominal cavity dissemination of splenic cells if the splenic capsule is broken, as seen by experimental evidence of tumoral cell mobilization by the pneumoperitoneum. We evaluated the features of splenosis after splenectomy operated via an open approach or under laparoscopic control in an experimental model in the rat. A total of 65 Sprague-Dawley rats were distributed in seven groups that included the open approach, CO2 pneumoperitoneum LS, or wall lift LS with or without a splenic graft. Splenic function was evaluated 90 day later through (1) scintigraphy with Tc-labeled heat-damaged erythrocytes; (2) determination of circulating "pitted" cells; and (3) analysis of the distribution of splenic pulp in the peritoneal cavity. Scintigraphy did not show viable residual tissue in any group after splenectomy; splenic activity in the splenic fossa was observed in 40% of the animals with grafts. Splenectomy increased the "pit" cell count, but it was reduced to normal values with a splenic graft. Necropsy showed normal splenic tissue in the splenic fossa in 100% of animals with a graft. Abdominal implants were observed significantly more frequent after CO2 LS than after the open surgery or a wall lift LS (80% vs. 20% vs. 30%; p < 0.05). In addition, trocar site implants were observed with CO2 LS (n = 3) or wall lift LS (n = 2), whereas there were no implants in the wound in the open group. We conclude that in an experimental rat model the pneumoperitoneum may facilitate abdominal splenosis after LS if the splenic capsule is ruptured or if splenic tissue spills compared with surgery without gas (open or laparoscopic).