Analysis of factors associated with operative difficulty in thoracoscopic esophageal cancer surgery in the left-decubitus position: a single-center retrospective study

BACKGROUND: The degree of difficulty in the overall procedure and forceps handling encountered by surgeons is greatly influenced by the positional relationship of intrathoracic organs in minimally invasive esophagectomy. This study aimed to identify the anatomical factors associated with the difficulty of minimally invasive esophagectomy assessed by intraoperative injuries and postoperative outcomes. METHODS: Minimally invasive esophagectomy in the left-decubitus position was performed in 258 patients. We defined α (mm) as the anteroposterior distance between the front of the vertebral body and aorta, β (mm) as the distance between the center of the vertebral body and center of the aorta, and γ (degree) as the angle formed at surgeon’s right-hand port site by insertion of lines from the front of aorta and from the front of vertebrae in the computed tomography slice at the operator’s right-hand forceps hole level. We retrospectively analyzed the correlations among clinico-anatomical factors, surgeon- or assistant-caused intraoperative organ injuries, and postoperative complications. RESULTS: Intraoperative injuries significantly correlated with shorter α (0.2 vs. 3.9), longer β (33.0 vs. 30.5), smaller γ (3.0 vs. 4.3), R1 resection (18.5% vs. 8.3%), and the presence of intrathoracic adhesion (46% vs. 26%) compared with the non-injured group. Division of the median values into two groups showed that shorter α and smaller γ were significantly associated with organ injury. Longer β was significantly associated with postoperative tachycardia onset, respiratory complications, and mediastinal recurrence. Furthermore, the occurrence of intraoperative injuries was significantly associated with the onset of postoperative pulmonary complications. CONCLUSIONS: Intrathoracic anatomical features greatly affected the procedural difficulty of minimally invasive esophagectomy, suggesting that preoperative computed tomography simulation and appropriate port settings may improve surgical outcomes.