A Modified Technique for Partial Pneumonectomy in the Mouse

Background: Partial pneumonectomy (PNX) in mice results in compensatory growth in the remaining lung and is a useful model for lung repair. However, common pitfalls to the technique present a challenge for researchers. A complete description of murine PNX is thus provided, with a modification that, in our hands, enhanced animal survival. Materials and Methods: 10 ± 2 weeks old mice were anesthetized using 5% inhalational isoflurane via tracheotomy. Mechanical ventilation was provided using a Harvard Model 687 ventilator. In a procedure optimized to be performed in ≤20 min, left lateral thoracotomy was used to access to the left lung, which was grasped with a blunt forceps just distal to the hilum and clipped using a single 5-mm neuro clip. The left lung was resected, leaving a small rim of lung tissue immediately adjacent to the clip. The thoracotomy was closed, and while anesthesia was titrated, sterile saline was injected subcutaneously to replace insensible fluid losses. Upon return of spontaneous breaths, the trachea was decannulated, and the tracheotomy was closed. Results: Even when performed by a single operator, this modified technique produced a survival rate of >85% during the procedure and >90% up to seven days postoperatively in wild-type C57BL/6J mice. Conclusions: Minimizing the time required to perform left lobe pneumonectomy is critical for animal survival. Using a 5-mm neuro clip, rather than silk suture, to isolate the lobe streamlines the procedure, helps reduce cardiac arrythmia, and results in significantly increased rates of intraoperative and immediate postoperative survival.