Improvements of surgical techniques in a rat model of an orthotopic single lung transplant

Abstract

Background: Rats are widely used in modeling orthotopic lung transplantation. Recently the introduction of the cuff technique has greatly facilitated the anastomosing procedure used during the transplant. However, the procedure is still associated with several drawbacks including twisting of blood vessels, tissue injury and the extensive time required for the procedure. This study was performed to optimize the model of rat lung transplantation (LT) with the cuff technique.

Methods: A total of 42 adult Lewis rats received orthotopic LT with our newly modified procedures. The modified procedures were based on the traditional procedure and incorporated improvements involving orotracheal intubation; a cuff without a tail; conservative dissection in the hilum; preservation of the left lung during anastomosis; successive anatomizing of the bronchus, the pulmonary vein, and the pulmonary artery; and one operator.

Results: Transplants were performed in 42 rats with a successful rate of 95.23% (40/42). The mean duration for the complete procedure was 82.93 ± 14.56 minutes. All anastomoses were completed in one attempt without vessel laceration, twisting or angulation. In our study, two animals died within three days and one animal died ten days after the operation. All grafts were well inflated with robust blood perfusion and functioned normally as demonstrated by blood gas analysis.

Conclusions: We have developed a modified orthotopic LT technique that can be easily performed while overcoming major drawbacks. The modified technique has many advantages, such as easy graft implanting, shortened operation time, fewer complications and high reproducibility.

Figure 1

Improvements on cuff technique. (A) Conservative dissection in hilum. (B) Traditional cuff and implantation. (C) Modified cuff and implantation.

Figure 2

Dynamics of blood pressure and electrocardiogram during operation. (A) Preoperative. (B) Mechanical ventilation begins. (C) Mechanical ventilating. (D) Intra-operative. (E) Left hilum blocked. (F) Graft reperfused. (G) Postoperative.

Figure 3

Postoperative recipient at day 7, showing well-inflated graft and potent function.

Figure 4

Representative ischemia-reperfusion injury following transplantation. (A) Three days after operation, transplant recipient manifests widened alveolar septa, presence of multiple alveolar macrophages and neutrophil, and obvious edema. (B) Seven days after operation, transplant recipient manifests nearly normal septa, very few alveolar macrophages and sparse edema. (hematoxylin and eosin. 400x).