The core-out technique causes a significant decrease in squeeze pressures, which reflects damage to the external anal sphincter. This could lead to incontinence in high-risk patients. Curettage is a simple technique that preserves the values of squeeze pressures without increasing recurrence rates.

Peripheral arterial disease (PAD) is a narrowing of the arteries in the legs, usually due to atherosclerosis; it becomes more common with aging. The prevalence of PAD in the general population is about 12%, affecting up to 20% of those over the age of 70 years [1]. Depending on its severity, treatment options include medication, angioplasty/stenting or bypass surgery. Patients with PAD are at an exceptionally high risk for cardiovascular events, increasing the risk of surgical treatment. A 63-year-old man with known history of heavy smoking had a low rectal cancer invading the levator ani muscle, left-side neurovascular bundle and periosteum of the S5 sacrum. The most important problem was the presence of arteriosclerosis obliterans, one of the most common manifestations of PAD. Right-sided arterial occlusion was observed from the common iliac artery to the femoral artery. In addition, the left common iliac artery was also severely stenotic. Before cancer treatment, the left iliac artery was revascularized by stent placement and femoro-femoral arterial bypass surgery. Following preoperative chemoradiotherapy, laparoscopic abdominoperineal excision with en bloc resection of the left neurovascular bundle and S5 sacrum was performed while preserving the left-sided iliac vessels (see Video S1), because the blood flow toward the pelvic organs and both legs was supplied only through the left-sided iliac arteries. Blood flow toward the pelvic organs is significantly decreased by clamping the internal iliac artery at the point below the superior gluteal artery [2]. Bladder necrosis can occur following bilateral ligation of the internal iliac artery [3]. The total operative time was 382 min and the blood loss was 530 ml. Final pathology showed negative resection margins. Two weeks postoperatively the patient was discharged without any adverse events. At 36 months after surgery, no recurrence or clinical symptoms were observed. In PAD cases like this, surgeons need to consider the blood flow toward the bladder by preserving the superior and inferior vesical arteries.