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Collin (Collins) Abdominal Retractor

The Collin, also called Collins in clinical literature, is a self-retaining abdominal retractor that holds wound edges apart without continuous manual traction. It is encountered in lower-abdominal gynecologic and cesarean surgery and can be useful when a transverse abdominal incision gives the required reconstructive access.[1]

Design and configurations​

The exact frame, spreading mechanism and blade set depend on the model. KLS Martin lists complete Collin retractors with paired lateral blades and a central blade. Two examples illustrate the differences:[1]

Catalog modelLateral bladesCentral bladeListed spread
15-824-00-0745 × 80 mm50 × 75 mm100 mm
15-826-00-0760 × 80 mm60 × 75 mm140 mm

The catalog lists compatible replacement blades and a spare screw for the larger model. Identify the actual locking mechanism before use; “Collins” does not mean every model has the same ratchet or interchangeable blades.

This is an abdominal instrument, distinct from similarly named Collin vaginal specula and Collin-Hartmann handheld retractors. Specify the pattern and blade configuration when preparing a tray.

Practical applications and setup​

For a low abdominal incision, the lateral blades maintain the wound opening while an additional blade or handheld instrument supplies directed deeper exposure. The frame does not replace the need to mobilize the operative plane. In a narrow, deep or scarred pelvis, a table-mounted Bookwalter, Omni-Tract or Thompson may offer more independently adjustable directions of traction.

A practical setup sequence is:

  1. Check the assembled frame, locks and matching blade attachments before placement.
  2. Select blades that support the abdominal wall without extending unnecessarily into the pelvis.
  3. Place blades under direct vision, excluding bowel and other structures from the contact and locking surfaces.
  4. Open incrementally to obtain the required view. Add directed exposure where needed rather than relying on maximal lateral spread.
  5. Reassess blade depth and tissue pressure after changes in positioning, packing or the operative target.
  6. Release traction and remove blades in a controlled sequence, accounting for removable components.

Avoid concentrated pressure on deep lateral pelvic structures. There is no single “over the psoas” or “medial to the psoas” instruction that makes all blade placements safe. Identify the tissue in contact with the blade and reassess it.

Reconstructive relevance​

The Collin is not a primary reconstructive instrument. It is the retractor the reconstructive surgeon or urogynecologist meets in adjacent operations:

  • Cesarean delivery: the traditional metal self-retaining retractor for the Pfannenstiel incision in many centers, relevant when ureteral injury, fistula or peripartum hysterectomy brings a urologic surgeon into the case.
  • Open gynecologic surgery through transverse lower-abdominal incisions: hysterectomy, adnexal and pelvic mass surgery, and transverse approaches to ureteral reimplantation or fistula repair.
  • Open urogynecologic procedures through a Pfannenstiel incision: for example abdominal sacrocolpopexy in a thin patient or low ureteral reimplantation.

For midline laparotomy or deeper pelvic work, a Balfour, Bookwalter, Omni-Tract or Thompson is usually preferred.

Relationship to a wound protector​

A Collin holds the wound with metal blades. A dual-ring wound protector/retractor combines circumferential retraction with a sheath lining the incision. These are mechanically different tools; the choice depends on access and the operation.

The evidence comes from cesarean delivery:

  • Hinkson 2016 (single-center randomized trial, Charité, Berlin, first planned cesareans in low-risk women; 98 Alexis, 100 Collins): surgical site infection was 1% with the Alexis and 8% with the Collins (RR 7.84, 95% CI 2.45–70.71, p = 0.035).[2]
  • Waring 2018 (meta-analysis of 6 randomized trials, 1,669 women, O-ring versus routine care): no overall reduction in infection (RR 0.76, 95% CI 0.34–1.70). A planned subgroup with BMI below 35 showed a reduction (RR 0.34, 95% CI 0.12–0.98). The authors concluded that routine use was not justified.[3]
  • Scolari Childress 2016 (randomized trial of 301 obese women, median BMI 40.1, Alexis versus conventional handheld retractors): no difference in infection or wound disruption (20.6% versus 17.6%, p = 0.62).[4]

These results apply to cesarean delivery. They are not an infection-risk ranking for reconstructive operations.

Femoral neuropathy​

Femoral neuropathy is the main nerve complication of self-retaining abdominal retractors with deep lateral blades. The lateral blade can compress the femoral nerve against the psoas within the pelvis.[5][6]

  • Prospective studies reported femoral neuropathy after pelvic abdominal surgery with self-retaining retractors (7.45%, 282 cases) and after elective total abdominal hysterectomy (11.6%, 17/147).[7][8] Complaints lasted 3–90 and 3–65 days, respectively; 17 patients in the first study had residual mild symptoms for up to 116 days. Most recovered spontaneously.[7][8]
  • Transverse abdominal incisions and thin body habitus are reported risk factors for femoral neuropathy during gynecologic surgery; consider both when positioning the Collin's lateral blades.[5]
  • Permanent deficits have been reported.[9]
  • Precautions: use the shortest, narrowest blades that give exposure, loosen the frame periodically in long cases, and avoid tightening lateral blades against the pelvic sidewall.[5][6][9]

See also: Balfour, Deaver, Richardson.

References​

1. KLS Martin. Surgical instrument catalog: Collin abdominal retractors and replacement components. Manufacturer configurations, accessed September 20, 2026.

2. 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;203:232–238. doi:10.1016/j.ejogrb.2016.06.003.

3. 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.

4. 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.

5. 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.

6. Irvin W, Andersen W, Taylor P, Rice L. Minimizing the risk of neurologic injury in gynecologic surgery. Obstet Gynecol. 2004;103(2):374–382. doi:10.1097/01.AOG.0000110542.53489.c6.

7. 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):385–392. doi:10.1016/0028-2243(85)90062-0.

8. Kvist-Poulsen H, Borel J. Iatrogenic femoral neuropathy subsequent to abdominal hysterectomy: incidence and prevention. Obstet Gynecol. 1982;60(4):516–520. PMID 7121938.

9. 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):504–508. doi:10.1016/s0002-9610(97)00015-9.