V8 - Complex lateral pelvic node dissection after Simultaneous integrated boost(SIB) Radiotherapy

CME Eligible

Purpose/Background: Minimally invasive Lateral pelvic node dissection for rectal cancer is a challenging procedure with a definite learning curve.

The management of Locally advanced rectal cancers has conventionally involved multimodality treatment with neoadjuvant radiation and chemotherapy followed by surgery. The advent of newer techniques to deliver radiation boost poses a greater challenge to the surgeon for performing complex additional procedure like lateral pelvic lymph node dissection.

Methods/Interventions: This is a video of a patient undergoing left pelvic node dissection following Simultaneous integrated boost (SIB) radiotherapy to the lateral pelvic node demonstrating the complexity which may arise in such cases. The treatment related changes of neoadjuvant radiation and chemotherapy can lead to edematous tissue planes and extensive fibrosis which needs surgical expertise to ensure optimal oncological outcomes. With the 'Medial Psoas Approach', the external iliac vessels were reflected from lateral to medial aspect from psoas muscle for better delineation and fibrofatty tissue over it was removed from caudal to cranial aspect.This step helped in safely identifying the bifurcation of the common iliac artery, the internal iliac artery and the densely adherent lymph nodal mass. The left internal iliac artery was ligated for better exposure and en block resection of nodal mass which was subsequently dissected from surrounding structures, safeguarding the obturator nerve in posterior aspect. The obliterated umblical artery was ligated and divided and paravesical space dissected, lifting the tissue medial to bladder base .The branches of internal iliac vein encountered are sequentially ligated and divided as we continue to separate from nodal mass.Finally nodal mass is dissected from the levator ani and the lumbosacral trunk located on the floor.

Results/Outcomes: The final histopathology report revealed total 12 pelvic nodes , of which zero were positive for malignancy. However, these nodes showed acellular mucin changes which are treatment related .The patient had an uneventful postoperative stay and was discharged on sixth day.

Conclusion/Discussion: Lateral pelvic node dissection may present with additional challenges in cases which were treated with SIB Radiotherapy and needs surgical expertise to ensure safe and optimal oncological outcomes.

Left pelvic nodal mass post Neo-adjuvant therapy
Template of Left lateral pelvic node dissection with ligated internal iliac artery