# Recurrent Tumor in Colorectal Cancer Requiring Combined Resection of Iliac or Femoral Vessels: Report of Four Cases

## TL;DR

This paper reports four cases where colorectal cancer recurrences near blood vessels were surgically removed with vessel resection to achieve complete tumor removal.

## Contribution

The study provides clinical insights into the management of recurrent colorectal tumors involving vascular structures through case reports.

## Key findings

- Combined resection of recurrent tumors and adjacent vessels achieved R0 resection in four patients.
- Histological confirmation showed tumor proximity or invasion of vessels in three cases.
- Postoperative follow-up showed no vascular surgery-related complications in three surviving patients.

## Abstract

Recurrent tumors in colorectal cancer may be removed along with adjacent blood vessels to achieve R0 resection. However, it remains unclear whether to aggressively perform this procedure because it may cause serious intraoperative or postoperative complications.

In Case 1, a 62-year-old man underwent radical surgery for rectosigmoid cancer. Three years later, computed tomography scans revealed a disseminated nodule near the left external iliac vessels. We resected the tumor and vessels that were reconstructed by bypass surgery. Histologically, the margins of the tumor were in contact with the adventitia of the vessels. In Case 2, a 63-year-old man underwent radical surgery for ascending colon cancer. A nodule was detected at the right iliac fossa 16 years later and appeared to invade the right femoral vessels. After systemic chemotherapy, the nodule was removed with partial resection of the right femoral artery and vein that were reconstructed by end-to-end anastomosis and bypass surgery, respectively. Histologically, the tumor was located 0.7 mm from the vessels. In Case 3, a 67-year-old woman underwent radical multivisceral resection for obstructive rectosigmoid cancer invading the adjacent organs. Fifteen months later, she developed local recurrence and subsequently received chemotherapy. She underwent en bloc resection of the tumor and the left internal iliac artery (IIA) near the bifurcation. The left external iliac artery was reconstructed by end-to-end anastomosis. Direct invasion of the IIA was proven histologically. In Case 4, a 74-year-old woman underwent radical surgery for ascending colon cancer with high microsatellite instability. Eight months later, a recurrent tumor was detected near the right external iliac vessels. After pembrolizumab and chemoradiotherapy, we resected the tumor and part of the external iliac vein; the defect was primarily closed with sutures. No viable tumor cells were found in the specimen. During the follow-up period (median: 52 months), 3 patients were alive without vascular surgery-related complications.

It is difficult to accurately evaluate whether a recurrent tumor from colorectal cancer directly invades vessels using preoperative imaging. However, the combined resection of recurrent tumor and vessels may be required to achieve R0 resection, considering a short distance even in invasion-negative cases.