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Mixter Right-Angle Clamp

Ratcheted ring-handled dissecting clamp with jaws bent at 90° to the shaft — the universal "right angle" for passing behind tubular structures (vessels, ureter, ducts, nerves, vasal cord) and pulling a ligature, vessel loop, or tie around them. Indispensable on every open RU/urogyn pelvic tray; the canonical tool for the "pass-around-and-tie" step that anchors vessel ligation throughout open surgery.[1][2]

Design​

  • Jaw angle: jaws bent 90° relative to the shaft — the defining feature. Allows the tip to advance behind a structure perpendicular to the surgeon's line of approach.
  • Jaws: fine transversely serrated; no tip tooth.
  • Tips: relatively fine and tapered for precise dissection in tight planes.
  • Length: 14–28 cm (5.5–11 in); fine / standard / long variants for superficial work, mid-pelvic work, and deep pelvic / retropubic exposure.
  • Mechanism: ring-handled box lock with a multi-position ratchet.
  • Material: surgical-grade stainless steel.

The Mixter family also includes the Broglia modification specifically engineered for radical retropubic prostatectomy and cystectomy — an angled tip with curved geometry that navigates beneath the pubis to reach the dorsal venous complex.[1]

Reconstructive-Urology and Urogyn Uses​

The Mixter is the right instrument whenever a structure needs to be encircled before division or ligation:

  • Dorsal venous complex (DVC): passing around the DVC and puboprostatic ligaments during open radical retropubic prostatectomy and open cystectomy — the Broglia 1994 modification was specifically designed for this maneuver.[1]
  • Internal iliac / hypogastric vessel control during deep pelvic dissection in advanced reconstruction, hostile pelvic re-entry, and complex fistula repair.
  • Mesenteric vessels during open urinary diversion — passing ties around mesenteric arcades during ileal-conduit, neobladder, and continent-reservoir construction.
  • Ureter mobilization: passing a vessel loop around the ureter during ureteral reimplantation, ureteroureterostomy, ileal-ureter interposition, and ureterolysis for retroperitoneal fibrosis — atraumatic encirclement for tagged retraction.
  • Spermatic cord and vasal mobilization — encircling the cord during open inguinal orchiopexy / orchiectomy and the vas during vasovasostomy / varicocelectomy.
  • Pedicle handling — broad-ligament, IP, uterine, and cardinal pedicles during adjunctive hysterectomy and sacrocolpopexy.
  • Penile dorsal neurovascular bundle — encircling the DVC during Peyronie's plication, penile-disassembly procedures, and penile-shaft replantation work.
  • Tunneling: creating a passage for vascular grafts, vessel loops, or interposition flaps (omental, gracilis, peritoneal) during VVF / RVF / RUF repair.
  • Retraction: gentle angled retraction of small tubular structures (ureter, vas, dorsal nerve of the penis) out of the operative field.

The Pass-Around Technique​

  1. Identify the plane immediately adjacent to the target structure — the avascular cleft where the right angle will travel.
  2. Advance the closed tip behind the structure with gentle teasing motion; do not push against resistance.
  3. Open the jaws once the tip emerges on the far side; grasp the suture / tie / vessel loop offered by the assistant.
  4. Withdraw the Mixter with the tie in its jaws, drawing the tie around the structure.
  5. Pass the tie through to the surgeon, who ties down.

In tight or deep spaces the assistant "feeds" the tie into the open jaws while the surgeon holds position behind the structure. Size selection is critical: too large a Mixter in a confined space tears tissue; too small lacks the reach needed for deep encirclement. Most teams keep fine, standard, and long Mixters on the field for any open RU/urogyn pelvic case.

Distinctions from Adjacent Right-Angle / Dissecting Instruments​

InstrumentJaw angleBest fit
Mixter (this page)90° fine-tippedGeneral pass-around-and-tie; vessel / duct / ureter isolation
Gemini90° ultra-fineSmall / delicate structures; confined spaces
Lahey right angle~ 90° broader jawThyroid and bile-duct dissection; sturdier purchase
Mixter–Broglia modificationAngled with curved tipRetropubic prostatectomy / cystectomy DVC pass-around[1]
Maryland dissector (laparoscopic)Angled / curvedLaparoscopic / robotic equivalent
Schnidt (tonsil)Long curved, not 90°Reach-and-grasp hemostasis at depth
Kelly / Crile / PéanStraight or curved, not 90°Clamping, not pass-around

Technique Pearls​

  • Atraumatic on fragile vessels: portal vein, renal vein, iliac vessels, and dorsal venous complex all tolerate gentle spreading, not pushing. A torn DVC during prostatectomy or cystectomy is the canonical Mixter-related complication.[5][7]
  • Wrong-size penalty: use the smallest Mixter that reaches — a large fine Mixter in a small space deflects off the target plane and tears.
  • Confirm visibility on the far side: if the tip is not visible after passage, do not open the jaws — re-advance carefully or back out.

Historical Context​

Named for Samuel Jason Mixter (1855–1926), a general and neurosurgical pioneer at Massachusetts General Hospital in Boston and one of the early leaders of surgery at MGH.[3] His son William Jason Mixter (1880–1958) carried the name forward at MGH and is independently famous for the Mixter–Barr 1934 paper linking lumbar disc herniation to sciatica — the publication that founded modern spine surgery.[3][4]

The right-angle dissecting clamp Samuel Mixter introduced became so universal that "Mixter" is now interchangeable with "right angle" in operating-room parlance.[2] The instrument belongs to the broader hemostatic-and-dissecting-clamp lineage descending from Péan, Halsted, Kelly, and Crile.[6]

See also: Gemini, Schnidt (Tonsil), Kelly, Péan, DeBakey.

References​

1. Broglia L, Scattoni V, da Pozzo L, Rigatti P. "A modified right angle clamp for radical retropubic prostatectomy and cystectomy." Eur Urol. 1994;26(3):262–3. doi:10.1159/000475391

2. El-Sedfy A, Chamberlain RS. "Surgeons and their tools: a history of surgical instruments and their innovators. Part IV: pass me the forceps." Am Surg. 2015;81(2):124–7.

3. Barker FG. "The Massachusetts General Hospital. Early history and neurosurgery to 1939." J Neurosurg. 1993;79(6):948–59. doi:10.3171/jns.1993.79.6.0948

4. Stienen MN, Surbeck W, Tröhler U, Hildebrandt G. "Little-known Swiss contributions to the description, diagnosis, and surgery of lumbar disc disease before the Mixter and Barr era." J Neurosurg Spine. 2013;19(6):767–73. doi:10.3171/2013.8.SPINE121008

5. Ercolani G, Ravaioli M, Grazi GL, et al. "Use of vascular clamping in hepatic surgery: lessons learned from 1260 liver resections." Arch Surg. 2008;143(4):380–7. doi:10.1001/archsurg.143.4.380

6. Sachs M, Auth M, Encke A. "Historical development of surgical instruments exemplified by hemostatic forceps." World J Surg. 1998;22(5):499–504. doi:10.1007/s002689900424

7. Manship LL, Moore WM, Bynoe R, Bunt TJ. "Differential endothelial injury caused by vascular clamps and vessel loops. II. Atherosclerotic vessels." Am Surg. 1985;51(7):401–6.