Pelvic Neuroanatomy in Colorectal Surgery: Advances in Nerve Preservation for Optimized Functional Outcomes

Background: Pelvic autonomic nerve injury during colorectal surgery causes debilitating urinary, bowel, and sexual dysfunction. This review synthesizes contemporary evidence on neuroanatomy, nerve-sparing techniques, and functional outcomes to minimize iatrogenic injury while maintaining oncologic efficacy. Methods: Systematic analysis of cadaveric studies, clinical trials, and imaging advancements focused on the superior hypogastric plexus, hypogastric nerves, pelvic splanchnic nerves (S2–S4), and inferior hypogastric plexus. Surgical innovations evaluated included robotic-assisted dissection, fluorescence-guided visualization, and intraoperative neuromonitoring. We distinguished evidence for nerve identification from evidence for functional protection and graded study designs accordingly. Results: Anatomical variability (e.g., superior hypogastric plexus leftward deviation 58.8%; hypogastric nerve median width 3.5 mm) necessitates precision techniques. Nerve-sparing approaches reduce urinary dysfunction from 30–70% to 10–30% and sexual dysfunction from 40–80% to 15–30%. However, the functional benefit of specific technical steps is often derived from anatomical rationale and cohort studies, with limited randomized trials for individual maneuvers. While technique refinements such as Denonvilliers’ fascia preservation may offer early sexual function benefits, randomized evidence shows no 12-month urinary advantage and uncertainty regarding longer-term durability; routine adoption should be individualized. Advanced imaging (3 T MRI, diffusion tensor imaging) and fluorescence guidance improve pre-/intraoperative visualization, but randomized evidence for improved postoperative urinary or sexual function is limited. Randomized data support pelvic intraoperative neuromonitoring in reducing urinary deterioration; most adjuncts have observational or feasibility-level support. Conclusions: Integrating neuroanatomical knowledge with advanced technologies enhances identification and may support nerve-sparing execution; however, robust randomized evidence for durable functional protection of novel technologies and specific technical steps remains limited. Priorities include standardizing preservation protocols, conducting randomized trials that validate the efficacy of individual surgical maneuvers, linking identification to functional outcomes, and validating long-term patient-reported outcomes.