Construction of a nomogram model to predict technical difficulty in performing laparoscopic sphincter-preserving radical resection for rectal cancer

Figure 5 Measurements of waist circumference, anterior-posterior abdominal diameter and transverse abdominal diameter. Waist circumference (e): Circumference of the waist at the level of the umbilicus; anterior-posterior abdominal diameter (RS): Measurement distance from the umbilicus to the spine-wall intersection in the abdominal plane; transverse abdominal diameter (TU): Measurement distance along the horizontal line of the anterior margin of the lumbar vertebrae at the level of the umbilicus.