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Allis Clamp

Allis clamp showing the angled, interlocking-toothed jaws and ratcheted finger rings

Allis clamp — angled jaws with interlocking teeth, ratcheted finger rings. (Image: Wikimedia Commons, public domain.)

Ratcheted ring-handled tissue clamp with broad, slightly curved jaws bearing short interlocking teeth at the tips — the workhorse "hold-everything" clamp for skin, fascia, vaginal cuff, and resected tissue edges that need to stay put during dissection or specimen handling. Considered moderately atraumatic relative to the single-tooth tenaculum and the Kocher, but more traumatic than the Babcock; accordingly the Allis is for tissue that will be discarded or that can tolerate focal serosal trauma — not for bowel or ureter left in situ.

Design​

  • Jaws: broad, slightly curved, with multiple short interlocking teeth at the tip. Teeth are relatively blunt and broad — pressure is distributed across a wider footprint than the single point of a tenaculum.
  • Mechanism: ring-handled box lock with a ratchet — clamp stays locked without sustained hand pressure.
  • Tip configurations: 3×4, 4×5, 5×6, and 6×7 teeth are commonly available; larger tooth counts spread force further but lift less tenaciously.
  • Length: standard 15 cm (6 in); long Allis 24 cm (9.5 in) for deep pelvic and abdominal exposure.
  • Material: surgical-grade stainless steel.

Reconstructive-Urology and Urogyn Uses​

  • Vaginal-cuff and vaginal-flap retention — vaginal-cuff handling during open / vaginal hysterectomy, VVF / RVF repair, sacrocolpopexy vaginal-flap mobilization, anterior / posterior colporrhaphy flap handling, and high McCall culdoplasty.
  • Fascial-flap and graft harvest — rectus-fascia or fascia-lata pubovaginal-sling harvest; the Allis tents the fascial strip up to define cut edges.
  • Skin-edge traction for routine open RU dissection (scrotal, suprapubic, inguinal, perineal incisions).
  • Specimen handling — grasping a partial-nephrectomy or partial-cystectomy specimen, urachal remnant, or radical-orchiectomy cord during open exploration.
  • Urethrocutaneous-fistula tract grasp — secure traction on a small fistula tract during excision.
  • Mesh handling — grasping the leading edge of polypropylene or biologic mesh during placement.
  • Stable fascial-edge presentation during multi-layer closure of large midline or Pfannenstiel incisions after BNR, augmentation, diversion, or AUS pump-pouch exposure.
  • Vaginal stabilization for office / procedure-room tasks (IUD placement, endometrial biopsy) where the Allis can substitute for a single-tooth tenaculum with markedly less bleeding (see Evidence below).

Not appropriate for: bowel serosa or ureter left in situ (Babcock is the correct atraumatic clamp for those); vessel handling (DeBakey thumb forceps); microsurgical layers.

Evidence — Allis vs Single-Tooth Tenaculum for Cervical Stabilization​

A 2023 RCT (Andrews et al, Arch Gynecol Obstet) of cervical stabilization for IUD placement found that post-removal bleeding occurred in 6.3% of Allis-clamp cases vs 55.3% with the single-tooth tenaculum (RR 0.113, p < 0.001).[1] The data support the long-standing characterization of the Allis as a "moderately atraumatic" clamp on cervical and vaginal tissue, and provide a reasonable evidence base for substituting the Allis for the tenaculum in routine office urogynecology and reconstructive vaginal work where bleeding is undesirable.

Technique​

  • Grip: thumb-and-ring-finger grip through the rings, index finger along the shank for control.
  • Grasp: position the tip flush against the tissue edge; close to the first or second ratchet, not the third — overcompression mashes the tissue and gains nothing.
  • Tissue selection: skin, fascia, vaginal cuff, mesh, specimens, and tissue planned for resection. Avoid serosa, ureter, and any tissue intended to remain in situ.
  • Duration: release as soon as the next dissection step lets you reposition — sustained compression is the source of "atraumatic" instruments still causing tissue injury.

Distinctions from Adjacent Clamps​

ClampJaw / tipBest fit
AllisShort interlocking teeth, ratchetedSkin, fascia, vaginal cuff, resection-bound tissue
BabcockSmooth fenestrated, ratchetedBowel, ureter, hollow viscera in situ
KocherHeavy 1×2 teeth, ratchetedFascia and discarded tissue requiring strong grip
Single-tooth tenaculumOne sharp tooth, ratchetedCervical traction — more bleeding than Allis
DeBakey thumbParallel-ridge platformVessels, ureter handheld

Historical Context​

Named for Oscar Huntington Allis (1836–1921), a Philadelphia general surgeon and Hahnemann College professor whose name also attaches to the Allis sign (positive in displaced hip fracture, anchored on the relaxed iliotibial band) and the Allis inhaler (early ether-anesthesia device).

See also: Babcock, Kocher, DeBakey.

References​

1. Andrews B, Quick K, MacLeod E, Edwards K, Rone BK. "Cervical bleeding with cervical stabilization during IUD placement: Allis clamp versus single-tooth tenaculum, a randomized control trial." Arch Gynecol Obstet. 2023;307(4):1015–9. doi:10.1007/s00404-022-06784-x