Effects of experience and reference tools on laparoscopic length measurements.

Document Type

Journal Article

Publication Date



Surgical endoscopy





Inclusive Pages





Clinical Competence; Education, Medical--methods; Internship and Residency; Intestines--anatomy & histology; Laparoscopy--education; Students, Medical


INTRODUCTION: The accuracy of surgeons, and surgeons-in-training performing laparoscopic intestinal measurements is unknown. We evaluated the accuracy and precision of laparoscopic length measurements using a box-trainer model with and without the aid of a measuring tool.

METHODS: Surgical attendings, residents, and medical students were studied. A 500 cm length of rope was placed within a laparoscopic box trainer. Subjects completed two length measurements (LM). Participants measured 150 cm of rope for LM #1 and repeated the task using a 10-cm suture as a reference for LM #2. Measurement accuracy was tested by comparing mean LM between training level groups using an independent t test. Measurement precision was tested by comparing the mean deviation of LM from 150 cm.

RESULTS: 40 attendings, 40 residents, and 50 medical students were studied. In LM #1, there were no differences in mean length accuracy measured between training level groups. Residents significantly underestimated the true 150 cm length (p < 0.05). When LM #1 and LM #2 were compared, attending accuracy did not change but precision increased significantly (p < 0.01). Resident precision also significantly increased with the measuring tool (p < 0.001) and trended toward improved accuracy (p = 0.08). Student accuracy did not change, but a similar significant increase in precision was observed with the measurement tool (p = 0.001). Attendings performed both measurements faster than residents and students (p < 0.05). Residents performed faster than the students for both measurements (p < 0.05). Time for task completion significantly increased in medical students with the use of the measurement tool (p = 0.026).

CONCLUSIONS: These data suggest that use of a measurement tool in laparoscopic length measurement will yield better precision with no effect on operative time or procedural flow in more experienced operators. Standardization of methods of use and optimal training techniques remains to be determined.

Peer Reviewed