Assessment of Skeletal Muscle Quality via Intramuscular Adipose Tissue Content Predicts Surgical Morbidity and Prognosis after Pancreatoduodenectomy

Objectives: Sarcopenia is characterized by skeletal mass reduction and is associated with surgical morbidity and poor prognosis after pancreatoduodenectomy (PD). Sarcopenia diagnosis requires a combination of motor functional tests and skeletal muscle mass measurements. Conversely, intramuscular adipose tissue content (IMAC), an indicator of skeletal muscle quality, requires only computed tomography, providing convenient diagnostic information regarding the patient’s body composition. This study aimed to clarify the impact of IMAC on surgical morbidity and prognosis in patients undergoing PD. Methods: This study included 277 patients who underwent PD between January 2013 and December 2022. The relationship between surgical morbidity (Clavien–Dindo grade ≥ 3) and clinicopathological factors, including IMAC, was examined in all patients. Predictive factors associated with overall survival (OS) and recurrence-free survival (RFS) were evaluated in 122 pancreatic cancer patients. Results: A high IMAC independently predicted major complications (odds ratio 1.776, P =0.046) and was independently associated with poor OS (hazard ratio [HR], 1.694; P =0.038) and RFS (HR, 1.582; P =0.038). Patients with both high IMAC and CAR ≥ 0.015 had a significantly poorer OS than those with only one of the factors (5-year survival rate, 12.3% vs. 45.8%; P <0.001). Conclusion: IMAC, an indicator of skeletal muscle quality, provides convenient and highly valuable diagnostic information on body composition and predicts postoperative complications and prognosis in patients with malignant tumors undergoing PD.