Segmental Mastectomy

Preoperative status and intraoperative information were abstracted retrospectively from the hospital medical records and operating room records for each patient as described in Table 1 and Table 2. According to the Health Industry Standard of China: Adult Weight Determination (WS/T428-2013), body mass index (BMI) ≥24.0 kg/m² is considered overweight or obese. Based on this standard, BMI 24.0 kg/m² was used as the boundary for BMI grading. Surgical method was classified as lobectomy, segmentectomy, wedge resection, and combined surgical approach in our study. The combined surgical approach referred to combined lobectomy and segmentectomy, combined lobectomy and wedge resection, or combined segmentectomy and wedge resection. In this study, operation ranking referred to the order of operations in the same operating room on the same day.
The outcome of interest was cerebral infarction after lung resection. All patients with suspicious symptoms of cerebral infarction after surgery underwent urgent CT perfusion imaging of the brain. The diagnosis of postoperative cerebral infarction was based on neurological deficits and evidence of acute cerebral infarction on neuroimaging (4 (link)).

UVATS segmentectomy (Figure 1): we conduced surgery under general anesthesia with a double lumen endotracheal tube. The patient was positioned in lateral decubitus. We made a 3 to 4 cm skin incision located at the 5^th or 6^th intercostal space in the anterior-axillary line. We used a wound protector for exposure and utilized standard thoracoscopic instruments in conjunction with uniportal instruments for dissection. The technique used to perform segmentectomies was followed as described in detail by Okada and colleagues (21 ). We transected the segmental pulmonary veins and pulmonary arteries using either a vascular stapler, bipolar energy or between silk ligature depending on their size (Figure 2). The segmental bronchi were divided with either a surgical stapler or suture closed with vicryl. The delineation of the intersegmental plane was done by a combination of following the intersegmental veins, and by selective ventilation to create an inflation-deflation demarcation line. The parenchyma was divided with a surgical stapler. For lung cancer cases, we used intraoperative frozen exam routinely for regional N1 lymph nodes, and selectively for bronchial and parenchymal margins, to confirm absence of metastatic disease. If N1 lymph nodes were positive for malignancy, a completion lobectomy was performed.
MVATS segmentectomy: patients underwent similar anesthetic and patient positioning to UVATS. A 4 cm utility incision was made in the 4^th or 5^th intercostal space, one 12 mm port in the 8^th intercostal space (posterior axillary line), and a 5 mm port just below the tip of the scapula. The technique used to perform segmentectomy was conducted in a similar fashion to UVATS, although uniportal instruments were not required for MVATS.
We routinely performed regional anesthesia to aid in postoperative pain control, using an erector spinae block, paravertebral catheter, or liposomal bupivacaine at the discretion of the operating team. We cared for patients in a step-down unit using a standardized enhanced recovery after surgery protocol for thoracic surgery, which was specific to each academic institution although they did not differ significantly in content.