What would be your initial strategy be for vascular dissection of proximal end for the colorectal anastomosis?

A 67-year-old male presents with a rectal cancer 8 cm from the anal verge posterolateral, with a BMI of 32 kg/m2 plus high blood pressure and OSA (treated with CPAP). Staging revealed a T3N1 tumor that received neoadjuvant treatment. After 10 weeks, he was proposed to undergo a combined transabdominal and transanal approach total mesorectal excision. What would be your initial strategy be for vascular dissection of proximal end for the colorectal anastomosis?