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Collins Retractor

Wound-edge self-retaining metal abdominal retractor of the Balfour family, sized and shaped specifically for transverse lower-abdominal (Pfannenstiel / Joel-Cohen) incisions at cesarean section and open gynecologic surgery. In much of European practice it is the traditional self-retaining retractor at cesarean delivery, and the standard comparator against plastic dual-ring wound protector/retractors.[1][2]

Design​

  • Two opposing lateral blades on a ratchet-locking crossbar — incremental stepwise widening of the wound with constant lateral retraction; locks at the chosen width without an assistant.
  • Central (cephalad) blade — retracts the upper wound edge / bladder flap superiorly during lower-uterine-segment exposure (the "bladder blade" analogue).
  • Lateral blades are curved or slightly concave to seat against the wound edges; tip surface smooth or lightly serrated.
  • Surgical-grade stainless steel, autoclavable, reusable — contrast with disposable plastic dual-ring sheaths (e.g. Alexis O-Ring).
  • Sized for the transverse lower-abdominal incision — narrower span and shallower blades than the general-purpose Balfour, which it most closely resembles and with which the name is sometimes used interchangeably in European catalogues.[1][3][4]

Reconstructive-Urology and Urogyn Uses​

The Collins is not a primary RU instrument, but it is the workhorse retractor for several adjacent operations the reconstructive surgeon / urogynecologist participates in or inherits from:

  • Cesarean section — the traditional self-retaining retractor for the Pfannenstiel incision in many European centers; relevant to the urogyn audience when concurrent ureteral injury identification / repair, intentional VVF take-down, or peripartum hysterectomy is required.[1]
  • Open gynecologic surgery through transverse lower-abdominal incisions — hysterectomy, adnexal surgery, pelvic mass resection; adjacent to urogyn fistula repair and ureteric reimplantation when those cases are approached transversely.[4]
  • Open urogynecologic procedures where a Pfannenstiel rather than midline is chosen for cosmesis or scar reuse — abdominal sacrocolpopexy in a thin patient, low ureteric reimplantation, BNR via Pfannenstiel.

For midline laparotomy or deeper pelvic work, the Balfour, Bookwalter, Omni-Tract, or Thompson are preferred.

Comparison Table​

FeatureCollinsBalfourO'Sullivan-O'ConnorAlexis O-Ring
DesignWound-edge, ratchetWound-edge, ratchetWound-edge, ratchetPlastic dual-ring sheath
Primary useCesarean / pelvic GYNGeneral / GYN / RUCesarean / GYNCesarean / abdominal
IncisionTransverse (Pfannenstiel)Midline or transverseTransverseAny
Central bladeYesYes (removable bladder blade)Yes (bladder blade)No
Wound protectionNoNoNoYes (circumferential plastic barrier)
ReusableYesYesYesNo (disposable)
Femoral-nerve riskYesYesYesMinimal
SSI signal vs Alexis8% vs 1% in Charité RCT (non-obese)[1]Similar to CollinsSimilar to CollinsLower in non-obese; no benefit in obese[5]

Evidence — Collins vs Plastic Wound Protector​

The defining clinical-evidence comparison for the Collins is the Charité University Hospital RCT (Berlin, 2013–2015) of the Alexis O-Ring C-Section retractor vs the Collins in 198 first-planned cesareans (98 Alexis / 100 Collins) in a low-risk, non-obese population:[1]

  • SSI: 1% (Alexis) vs 8% (Collins) — RR 7.84 (95% CI 2.45–70.71), p = 0.035.
  • Operative time, blood loss, postoperative pain, and wound-healing satisfaction were similar.

The benefit, however, does not generalize:

  • Waring 2018 meta-analysis (6 RCTs, 1,669 women, O-ring vs standard care including Collins) — no overall SSI reduction (RR 0.76, 95% CI 0.34–1.70); benefit limited to a non-obese subgroup.[2]
  • Scolari Childress 2016 RCT in obese cesarean delivery (median BMI 40) — no reduction in SSI or wound disruption with the Alexis vs conventional retractor.[5]

The mechanism most often invoked for the Alexis advantage in low-risk patients is the circumferential plastic barrier and distributed retraction force, which avoid the focal wound-edge ischemia and direct contamination pathway of metal blades.[1][12][13] The SHEA/IDSA 2022 update notes a ~30% SSI reduction with dual-ring wound protectors across abdominal surgery (moderate evidence).[14]

Safety Profile​

The Collins shares the safety profile of all self-retaining metal abdominal retractors.

Femoral neuropathy is the dominant concern. The lateral blades can compress the femoral nerve against the psoas muscle within the pelvis:[6][7][8]

  • Prospective rates of 7.5–11.6% during abdominal hysterectomy with self-retaining retractors.[9][8]
  • Higher risk with transverse incisions (the exact setting Collins is designed for), thin habitus, prolonged operating time, and excessive blade tightening.[6]
  • Most cases self-limit over 3–65 days; rare permanent deficits are reported.[10][11]

Prevention:[6][7][10]

  • Use the shortest, narrowest blades that give adequate exposure.
  • Seat the lateral blades over (not medial to) the psoas muscle.
  • Periodically loosen the retractor on long cases.
  • Recognize that thin patients are at highest risk.

Wound-edge ischemia and SSI — metal blades compress and devascularize the wound edge; circumferential plastic sheaths distribute force more evenly, which is the leading mechanistic explanation for the Charité SSI signal in non-obese patients.[1][12][13]

Practical Considerations​

  • The Collins remains the default cesarean retractor in many European institutions where reusable stainless-steel instruments are preferred for cost and supply reasons.[1]
  • WHO 2016 conditionally recommends wound-protector devices in clean-contaminated, contaminated, and dirty abdominal procedures for SSI prevention, with explicit caveats about cost and low-resource availability.[13]
  • For cesarean delivery, the evidence for replacing the Collins with a plastic dual-ring retractor is BMI-dependent — the SSI advantage is most consistent in non-obese, low-risk patients and disappears at BMI ≥ 40.[1][5][2]

References​

1. Hinkson L, Siedentopf JP, Weichert A, Henrich W. Surgical site infection in cesarean sections with the use of a plastic sheath wound retractor compared to the traditional self-retaining metal retractor. Eur J Obstet Gynecol Reprod Biol. 2016;203:232-8. doi:10.1016/j.ejogrb.2016.06.003

2. Waring GJ, Shawer S, Hinshaw K. The use of O-ring retractors at caesarean section: a systematic review and meta analysis. Eur J Obstet Gynecol Reprod Biol. 2018;228:209-214. doi:10.1016/j.ejogrb.2018.06.037

3. Feliciano DV, DuBose JJ. Donald Church Balfour (1882-1963) and the Balfour self-retaining abdominal retractor. Am Surg. 2022:31348221114522. doi:10.1177/00031348221114522

4. Singh S, Maxwell D. Tools of the trade. Best Pract Res Clin Obstet Gynaecol. 2006;20(1):41-59. doi:10.1016/j.bpobgyn.2005.09.008

5. Scolari Childress KM, Gavard JA, Ward DG, Berger K, Gross GA. A barrier retractor to reduce surgical site infections and wound disruptions in obese patients undergoing cesarean delivery: a randomized controlled trial. Am J Obstet Gynecol. 2016;214(2):285.e1-285.e10. doi:10.1016/j.ajog.2015.09.096

6. Chan JK, Manetta A. Prevention of femoral nerve injuries in gynecologic surgery. Am J Obstet Gynecol. 2002;186(1):1-7. doi:10.1067/mob.2002.119182

7. Irvin W, Andersen W, Taylor P, Rice L. Minimizing the risk of neurologic injury in gynecologic surgery. Obstet Gynecol. 2004;103(2):374-82. doi:10.1097/01.AOG.0000110542.53489.c6

8. Kvist-Poulsen H, Borel J. Iatrogenic femoral neuropathy subsequent to abdominal hysterectomy: incidence and prevention. Obstet Gynecol. 1982;60(4):516-20.

9. Goldman JA, Feldberg D, Dicker D, Samuel N, Dekel A. Femoral neuropathy subsequent to abdominal hysterectomy: a comparative study. Eur J Obstet Gynecol Reprod Biol. 1985;20(6):385-92. doi:10.1016/0028-2243(85)90062-0

10. Dillavou ED, Anderson LR, Bernert RA, et al. Lower extremity iatrogenic nerve injury due to compression during intraabdominal surgery. Am J Surg. 1997;173(6):504-8. doi:10.1016/s0002-9610(97)00015-9

11. Moore AE, Stringer MD. Iatrogenic femoral nerve injury: a systematic review. Surg Radiol Anat. 2011;33(8):649-58. doi:10.1007/s00276-011-0791-0

12. De Simone B, Sartelli M, Coccolini F, et al. Intraoperative surgical site infection control and prevention: a position paper and future addendum to WSES intra-abdominal infections guidelines. World J Emerg Surg. 2020;15(1):10. doi:10.1186/s13017-020-0288-4

13. Allegranzi B, Zayed B, Bischoff P, et al. New WHO recommendations on intraoperative and postoperative measures for surgical site infection prevention: an evidence-based global perspective. Lancet Infect Dis. 2016;16(12):e288-e303. doi:10.1016/S1473-3099(16)30402-9

14. Calderwood MS, Anderson DJ, Bratzler DW, et al. Strategies to prevent surgical site infections in acute-care hospitals: 2022 update. Infect Control Hosp Epidemiol. 2023;44(5):695-720. doi:10.1017/ice.2023.67