Analysis of the Learning Curve for the "Modified Chopsticks Technique" in Endoscopic Endonasal Transsphenoidal Surgery for Pituitary Adenomas: A Single-Center Prospective Study.

Objective

The "chopsticks technique" is an endoscopic endonasal surgical method where a single surgeon independently manipulates the endoscope and two surgical instruments, aiming to enhance surgical efficiency and reduce reliance on an assistant. However, mastering this technique entails a significant time investment. This study modified the technique and delineated its learning curve, aiming to provide critical data for developing training programs and facilitating the clinical adoption of the modified chopsticks technique.

Methods

Data from 253 consecutive patients treated by the same surgeon using the modified chopsticks technique were prospectively collected. Primary outcome measures included total operative time, extent of tumor resection, hormonal levels, and perioperative complications. The learning curve was derived using cumulative sum (CUSUM) analysis. The peak of the curve determined the threshold case number, dividing the series into a learning phase and a proficiency phase. Surgical duration and outcomes were compared between these two phases.

Results

CUSUM analysis indicated that the operative time for the key phase stabilized after the 43rd case, marking the plateau of the learning curve. Compared to the first 43 cases, the total operative time in the subsequent 210 cases was significantly reduced by approximately 34% (P<0.001). The gross total resection rate was 84% during the learning phase and increased significantly to 95% in the proficiency phase (P=0.032). The incidence of intraoperative CSF leak was significantly reduced and the hormonal remission rate was significantly increased in the proficiency phase (P<0.001).

Conclusion

For experienced neurosurgeons, a distinct learning curve exists for mastering the chopsticks technique, with proficiency achieved after approximately 43 procedures. Once past the learning phase, this technique significantly improves surgical efficiency and consistency without increasing surgical risk. Proficiency is associated with markedly improved rates of tumor resection, hormonal remission and a reduction in the risk of intraoperative CSF leak.