Technical Guide: How to Match HRA & HRB Wound Protectors with Surgical Incision Length

Abstract

Wound protectors (also named incision retractors) are essential sterile surgical devices used to retract incision edges, isolate wound contamination, expand surgical visual field and reduce tumor cell implantation during laparotomy and laparoscopic procedures. The  manufacturer- Changzhou Haida Medical Equipment Co., Ltd. provides multi-spec HRA (TPU film open surgery type) and HRB (silicone minimally invasive trocar type) product lines, yet many clinical nurses, operating room purchasers and medical distributors lack standardized model-incision matching reference.This paper sorts out the parameter logic of HRA/HRB series wound protectors, lists complete specification-incision matching tables, and combines a large number of real clinical operation cases to form a systematic technical selection scheme, which can be used for hospital procurement reference, medical staff training and distributor product promotion material.

Keywords: wound protector; incision retractor HRA; HRB; surgical incision; model selection; clinical matching

Figure 1: Visual distinction between HRA (TPU film open type, left two) and HRB (silicone mini trocar type, right two)

1. Core Parameter Definition & Calculation Standard

1.1 Specification Nomenclature Rule

All HRA/HRB models follow unified coding format: D2/D1-D3/L

Figure 2: Standard dimension marking diagram (D1=Outer ring, D2=Inner ring, D3=Channel diameter, L=Channel height)

· D1: Outer ring diameter

· D2: Inner ring diameter

· D3: Channel inner diameter (the decisive parameter for matching incision length)

· L: Channel height/length, only applicable to distinguish abdominal wall thickness, irrelevant to incision length

1.2 Safe Incision Calculation Formula (Industry Universal Standard)

Minimum applicable skin incision = D3 × 0.4 Maximum safe skin incision = D3 × 0.8

1.3 Basic Selection Principles

1. Unit of all dimensional parameters: mm; divide by 10 to convert into centimeter for clinical communication.

2. Clinical priority: adopt the middle interval of recommended incision range; reserve 10–20 mm safety margin below upper limit to avoid ring slippage during specimen removal and surgical traction.

3. Channel height classification: L=150 / L=170 for patients with thin abdominal wall (BMI＜24); L=250 extended channel for obese patients, repeated laparotomy and thick subcutaneous fat layer.

4. Series positioning difference: HRA (TPU elastic film) for long open abdominal incisions; HRB (soft silicone) for laparoscopic trocar holes, specimen extraction mini-incisions and single-port minimally invasive surgery.

Figure 3: Complete size lineup of HRA TPU wound protectors for open laparotomy

2. Complete Specification-Incision Matching Table

2.1 HRA Series (TPU Film for Large Open Incision)

2.2 HRB Series (Silicone for Minimally Invasive Trocar & Specimen Port)

3. Real Clinical Matching Application Cases

3.1 Classic Matching Cases of HRA Series Open Surgery

Case 1: HRA 150/160-150/250 (Core General Model)

· Actual incision length: 9 cm lower abdominal midline incision

· Surgical type: total abdominal hysterectomy, secondary cesarean section

· Patient feature: BMI 24–28, moderate thick subcutaneous fat

· Matching basis: D3=150 mm, safe incision range 6–12 cm; 9 cm incision stays in optimal middle interval with sufficient safety margin. L=250 extended channel fully wraps full-thickness abdominal wall, effectively preventing inner/outer ring detachment during fetal delivery and tumor specimen removal.

· Risk reminder: Do not use this model when incision reaches 12–13 cm; upgrade to HRA 180/190-180/250.

Case 2: HRA 180/190-180/250 for Obese Puerpera

· Incision length: 12 cm paramedian abdominal incision

· Operation: repeat cesarean section for obese patients, large uterine myomectomy

· Patient feature: BMI＞28, thick abdominal fat, multiple previous abdominal adhesions

· Matching logic: Max safe incision up to 14.4 cm, large channel diameter ensures complete delivery of fetus and large soft tissue mass without extrusion rupture; lengthened channel adapts to thick fat layer to avoid inward slippage.

Case 3: HRA 120/130-120/250 for Conventional Laparotomy

· Incision length: 7 cm

· Operation: cholecystectomy, benign gastric lesion resection, primary cesarean section of normal weight women

· Applicable crowd: BMI 22–26, no history of multiple abdominal surgeries

· Advantage: Balanced channel size, high cost performance, covers most routine general surgery and obstetric open operations.

3.2 HRB Minimally Invasive Series Matching Cases

Case 1: HRB 50/40--25/25 Routine Laparoscopic Operation Port

· Incision length: 1.5 cm

· Scene: gynecologic laparoscopy, general surgery cholecystectomy main instrument channel

· Advantage: Soft silicone material reduces extrusion damage to puncture edge tissue; 1.0–2.0 cm incision range matches standard 10 mm trocar, the most widely stocked model in minimally invasive operating rooms.

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