Laparoscopic Rectal Cancer Resection With Pelvic Autonomic Nerve Preservation in Males: A Prospective Single-Center Study

Nerve-preserving rectal resection cut post-op sexual dysfunction to 7.7%, but IIEF-5 scores still fell significantly at 6 months.

Journal: World Journal of Surgery | Published: 2026-01-30 | Type: Prospective single-center single-arm trial | PMID: 41618056 Authors: Xie Yequan et al., Guangdong Second Provincial General Hospital / Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China Funding/COI: Guangdong Natural Science Funds; Guangzhou Key Project R&D Program; Postdoctoral Research Project, Guangdong Second Provincial General Hospital. No COI listed.

Summary

Pelvic autonomic nerve preservation (PANP) during laparoscopic rectal cancer surgery aims to protect the nerve bundles that control erection and urination. This prospective trial of 70 operated men found that 6 months post-surgery, IIEF-5 erectile function scores dropped from 24.10 to 22.85 — a statistically significant decline, though both values sit in the normal range. Seven percent developed frank sexual dysfunction. The study's pitch that PANP "effectively preserves" function while delivering good oncological results is technically defensible but glosses over the real residual harm.

Claims

• IIEF-5 score decreased from 24.10 ± 1.21 (pre-op) to 22.85 ± 3.66 (post-op) at 6 months (p = 0.003)
• IPSS urinary symptom score increased from 1.89 ± 1.86 to 2.11 ± 2.06 (p = 0.018), indicating slight worsening
• 5 of 65 evaluable patients (7.69%) developed sexual dysfunction post-operatively
• 2 patients (3.08%) developed moderate urinary dysfunction
• Total mesorectal excision (TME) quality was complete in 94.29% (66/70) and near-complete in 5.71% (4/70)
• Circumferential resection margin (CRM) positivity: 2.86% (2/70); distal margin positivity: 1.43% (1/70)
• Mean post-operative hospital stay: 7.80 ± 2.44 days
• Univariate analysis flagged surgical procedure type, tumor distance to anal verge, TNM stage, neoadjuvant chemoradiotherapy (nCRT), stoma formation, and autonomic nerve completeness as risk factors — but none reached significance in multivariate analysis

Study Quality

This is a prospective single-center, single-arm study — a meaningful step above retrospective chart pulls, but the absence of a control group (non-PANP surgery) is the central methodological problem. Without a comparator, it is impossible to quantify how much nerve preservation actually helps; the sexual dysfunction rate might be higher or lower than conventional resection, and this study cannot tell you. Ninety-one patients were enrolled but only 70 underwent the laparoscopic procedure and 65 were evaluable at 6 months — 5 lost to follow-up. The multivariate analysis finding no independent risk factors is almost certainly a power issue: with 5 sexual dysfunction events across 65 patients, the study is severely underpowered to detect predictors. Six months is also a short follow-up window; nerve injury can improve or worsen beyond that horizon.

Red Flags

• No control arm. Single-arm design cannot establish that PANP improves outcomes over conventional surgery; it can only report absolute rates
• Underpowered for risk factor analysis. Five sexual dysfunction events in 65 men cannot reliably support multivariate modeling; the "no independent risk factors" conclusion is a null result from an underpowered test, not a finding
• Short follow-up. Six months may not capture the full trajectory of nerve recovery or late-onset dysfunction
• Loss to follow-up. Five patients (7.1%) missing from the primary outcome; with only 5 dysfunction events reported, those 5 could meaningfully change the picture
• Single center. Guangdong Second Provincial General Hospital's results may not generalize — the authors themselves restrict conclusions to "high-flow centers and experienced surgeons"
• No COI disclosure. The funding sources are regional government grants, which is lower-risk than industry funding, but the absence of any COI statement is a reporting gap

Strengths

• Prospective design with genitourinary function as the pre-specified primary outcome — genuinely uncommon in this surgical literature
• Used validated, standardized instruments (IIEF-5 for erectile function, IPSS for urinary symptoms)
• Oncological quality metrics are solid: 94.3% complete TME, 2.86% CRM positivity
• Reports absolute rates, not just relative improvements, making the numbers usable
• Intraoperative documentation of nerve preservation completeness adds some granularity

Verdict

This study is useful as a prospective feasibility report from an experienced surgical center, and the oncological results are respectable. But the core claim — that PANP "effectively preserves" function — is undermined by the statistically significant IIEF-5 decline and the 7.7% frank dysfunction rate, with no comparator arm to contextualize either number. The multivariate risk factor analysis should be ignored: you cannot model predictors from 5 events. Worth reading if you're benchmarking surgical dysfunction rates for this procedure; not worth citing as evidence that PANP is definitively protective.