Natural orifice translumenal endoscopic surgery (NOTES) partial nephrectomy in a porcine model

Background This study aimed to evaluate the feasibility of natural orifice translumenal endoscopic surgery (NOTES) transgastric partial nephrectomy without hilar clamping in a porcine model. Methods A 45-kg male pig was placed in the supine position after endotracheal general anesthesia. A therapeutic gastroscope was introduced through the esophagus, and a 2-cm gastrotomy was performed using a diathermy electrocautery needle at the junction of the fundus and the proximal body. After incision of Gerota’s fascia, the left kidney’s upper pole was excised using the thulium laser without hilar dissection or clamping. An endoscopic wire loop was used to entrap and extract the specimen into the stomach. The gastroscope was subsequently withdrawn with the intact specimen. After hemostasis via reinsertion of the endoscope was ensured, metal clips were applied endoscopically to close the gastrotomy. Results The total operative time for the NOTES transgastric partial nephrectomy was 240 min. Use of the therapeutic double-channel gastroscope allowed for scarless NOTES. The available 3.7- and 2.8-mm gastroscope ports were used for gastrotomy, excision, removal of the specimen, and endoscopic clip application. The procedure was performed in a nonischemic fashion with application of the thulium laser, which provided adequate hemostasis. No further interventions such as suturing of the renal capsule or use of hemostatic agents were required. The final specimen was 3 cm in size, and the estimated blood loss was 200 ml. A major drawback of the thulium laser was excessive smoke produced by vaporization of the tissue, which was minimized with the use of external irrigation. Conclusion The findings show that NOTES transgastric partial nephrectomy with thulium laser is feasible. Further studies are needed to demonstrate long-term efficacy and provide additional data regarding practical applications of this novel approach and technique.