Study design and study setting

This is a prospective study—of patients attending NCI, Cairo University, from December 2020 to December 2023. We aimed to establish a strategy for prophylactic PALND. The description of predictors for pathological para-aortic lymph node metastasis, which was not evident in pre-operative radiological investigations, allows us to detect colorectal cancer patients who will benefit from the over-treatment protocol (prophylactic para-aortic lymph node dissection).

Patients were complaining of left colonic cancer or recto-sigmoid cancer and underwent either left hemicolectomy, sigmoid colectomy, or LAR; all cases were treated by one team of two colorectal surgeons. All patients underwent formal mesenteric LN dissection and prophylactic para-aortic LN dissection.

The characteristics of participantsInclusion criteria

Patients were complaining of left colonic or rectosigmoid adenocarcinoma at any stage and were candidates for surgery; radiologically, they had no suspected para-aortic pathological lymphadenopathy.

Exclusion criteria

Patients with radiologically suspected para-aortic pathological lymphadenopathy (more than 7 mm radiologically seen by 2 different radio-diagnosis consultants) and patients with recurrent cancer colon.

InterventionPre-intervention evaluation

A detailed history was obtained from all participants regarding their age, sex, medical history, family history, previous malignancy, pre-operative investigations including (CEA & CA19.9), location of the tumor, pre-operative staging (based on radiological findings), pathological details, neo-adjuvant therapy, operative details including (operative procedure, operative time, intra-operative blood loss), postoperative complications including (hemorrhage, lymphorrhea & urine retention), hospital stay, final pathological details after surgery, adjuvant therapy and also we reported the recurrence during follow up which was based on serum TMs every 3 months, radiological assessment (Tri-phasic CT plus or minus MRI pelvis) every 6 months and colonoscopy every one year were also recorded.

Technical intervention

Under general anesthesia in the supine position, abdominal exploration was carried out through a midline incision. Mobilization of the sigmoid colon, descending colon and splenic flexure via sharp dissection of the Toldt's line, identification of the left ureter, identification of the right ureter, identification and preservation of the inferior hypogastric plexus, identification with division and ligation of the inferior mesenteric artery and vein from their origins at the level of D.J junction with orientation of the pedicle stump, identification of the right ureter, dissection of the sigmoid colon and rectum inferiorly from pre-sacral fascia in avascular plane with preservation of the inferior hypogastric plexus, dissection of the rectum anteriorly from the bladder trigon and from seminal vesicles, dissection of the rectum laterally from pelvic wall under complete vision of both ureters and both Pelvic splanchnic nerves (nervi erigentes), the rectal lesion was in mid-rectum and extending downwards till low rectum, after obtaining an adequate margins proximally, division of the colon above level of sigmoid colon and orienting the specimen proximally via silk sutures, after obtaining an adequate margins distally, division of the rectum just at the ano-rectal junction via the contour stapler and extraction of the specimen of the LAR. Performing colo-anal anastomosis via circular stapler Fr31 (Covidien) after insertion of the anvil proximally in the colon, testing anastomosis and it was watertight and airtight.

Technical notes

After resection of the primary tumor and performing formal mesenteric LN dissection with high ligation of the vessels from their origin in the aorta, para-aortic LN dissection was performed with landmarks of the left renal vein superiorly and bifurcation of the left common iliac artery inferiorly, with dissection of all connective tissues around the aorta and IVC Fig. 3.

Statistical analysisStatistical method

Version 26 of the SPSS (statistical package for social science) statistical tool will be used for data analysis. The mean, standard deviation, or median and range will be used to summarize numerical data. Depending on the type of data, mean ± SD was used to represent quantitative data, while numbers and percentages were used to represent qualitative data. Statistical significance was set at p < 0.05.