Colorectal Surgery Review

Lower GI Bleeds

Essential knowledge for the management of Lower GI Hemorrhage (LGIB), a common and high-stakes emergency. Initial management requires recognizing if the source is likely upper GI (hematochezia plus instability) and strict transfusion targets (Hgb 7; Hgb 9 for cardiovascular risk patients). Risk stratification hinges on the Shock Index and the Oakland Score, where a score of eight or less predicts safe outpatient discharge. The diagnostic pathway utilizes CTA for low-flow bleeds and angiography for high-flow bleeds. For endoscopic intervention, clips are strictly preferred over thermal energy for diverticular bleeding due to perforation risk. Surgical intervention is the last resort, emphasizing the need for India Ink tattooing to localize the source, allowing for a targeted segmental colectomy rather than a high-morbidity blind subtotal colectomy.

Large Bowel Obstruction

A crucial review of Large Bowel Obstruction (LBO), emphasizing the foundational physiology of the closed-loop obstruction caused by a competent ileocecal valve, leading to imminent perforation risk dictated by the Law of Laplace (highest risk at the cecum). CT is the definitive modality for locating the transition point. Management of malignant LBO is highly sensitive; emergency right colectomy is associated with 10% mortality and 14% leak rate. While Subtotal Colectomy (STC) avoids a high-risk anastomosis, it carries a high functional cost (41% of patients report high bowel frequency). For Sigmoid Volvulus, initial endoscopic detorsion must be followed by mandatory elective resection due to high recurrence risk (45-70%). Acute Colonic Pseudo-Obstruction (ACPO) is managed with Neostigmine, a highly effective agent that requires continuous cardiac monitoring due to the risk of severe bradycardia.

Diverticulosis

This episode reviews the significant evolution in the management of colonic diverticular disease, moving past old dogmas like the "second episode rule" and simple fiber deficiency hypothesis. Level 1 trials (Diabolo/AVOD) definitively show that antibiotics are not mandatory for stable, uncomplicated diverticulitis. The current indication for elective surgery is now based solely on symptom burden and reduced quality of life (QOL). For Hinchey III (purulent peritonitis), Laparoscopic Lavage (LL) is a valid, evidence-based option, as the increased initial risk of reintervention is balanced by a profoundly reduced rate of long-term stoma formation. For emergency resection in Hinchey IV, primary anastomosis (PA) is preferred in stable patients due to demonstrably superior stoma reversal rates compared to a Hartman's procedure.

Minimally Invasive Surgery

Comprehensive review of Minimally Invasive Surgery (MIS) for colorectal cancer, distinguishing the settled science of laparoscopic colon resection from the ongoing controversy of rectal resection. The episode details how pivotal trials (ACOSOG, ALaCaRT) failed to prove non-inferiority for laparoscopic proctectomy, primarily due to higher rates of compromised Circumferential Radial Margin (CRM) in the deep pelvis. Technical solutions like the Reverse Smile technique for anastmosis are discussed to mitigate weak spots from stapler limitations. The RoLAR trial demonstrated that robotics is not clinically superior to standard laparoscopy but is significantly more costly. Transanal Total Mesorectal Excision (TaTME) is presented as a radical technique to improve CRM, though it remains under intense scrutiny due to international concerns over multifocal recurrence patterns. Hand Assisted Laparoscopic Surgery (HALS) is noted as a practical bridge that retains MIS benefits while providing crucial haptic feedback for quality control.

Cytoreduction and HIPEC

Explores Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for Colorectal Peritoneal Metastases (CPM). Success relies entirely on meticulous patient selection and achieving complete macroscopic cytoreduction (CC0). The episode details the Peritoneal Cancer Index (PCI) for staging and emphasizes that for aggressive CPM, CC1 is essentially a failure to cure, whereas it may be acceptable for less aggressive PMP. The landmark Verwall trial proved a survival benefit for CRS + Mitomycin C HIPEC. However, the PRODIGE 7 trial introduced controversy by showing no survival benefit when using Oxaliplatin HIPEC after successful CRS alone, suggesting the choice of agent is critical. Current practice is shifting toward prevention and early detection in high-risk patients (e.g., T4 tumors, perforation).