Selective Non-Operative Management After Abdominal Gunshot and Blast Injuries in A Porcine Model

Summary

This work describes the establishment of porcine models of abdominal gunshot and blast injuries, provides the outcomes of selective non-operative management (SNOM) and immediate laparotomy in injured pigs, and emphasizes the need for careful observation and predefined criteria for conversion to surgery.

Abstract

The role of selective non-operative management (SNOM) after gunshot and blast injuries has been increasingly recognized but not explored in animal models. Overall, 24 male pigs were prepared, of which 12 were used to create a gunshot wound model, and the remaining 12 a blast injury model. Animals in each injury model were randomly divided into immediate surgery and SNOM groups using a computer-generated random sequence. Gunshot injury was created by firing a 7 mm, 1.45 g steel ball at the right upper abdomen from 10 cm under 170 bar. Blast injury was created by exposing the right upper abdomen to a high-pressure shock wave from 6 cm under 170–190 bar. In the SNOM group, focused assessment with sonography for trauma (FAST) was performed immediately after modeling and repeated when hemodynamic instability or clinical deterioration was suspected. Conversion to surgery was triggered by persistent heterogeneous echogenicity or hypoechoic fluid on FAST, hemodynamic instability, or progressive clinical deterioration. The primary outcome was the 7-day SNOM outcome. SNOM failure was defined as conversion to surgery or death. After gunshot injury modeling, the 7-day survival rate was 91.67% (11/12). In the immediate surgery group, 2 pigs underwent therapeutic laparotomy, and 4 underwent negative laparotomy. In the SNOM group, 1 pig underwent conversion to surgery, 1 died of hemorrhagic shock on day 1 after modeling, and 4 successfully completed SNOM. After blast injury modeling, the 7-day survival rate was 100% (12/12). In the immediate surgery group, 3 pigs underwent therapeutic laparotomy, and 3 underwent negative laparotomy. In the SNOM group, 2 pigs underwent conversion to surgery, and 4 completed successful SNOM. This work describes the establishment of preliminary injured porcine models, presents representative outcomes of the SNOM and immediate laparotomy strategies, and underscores the need for close monitoring when using the SNOM strategy.

Introduction

During World War I, mandatory laparotomy was considered the standard treatment for penetrating abdominal injuries to reduce mortality¹. In 1974, Nance et al. first reported the advantages of selective non-operative management (SNOM) over routine surgery for abdominal penetrating injuries². Since then, the SNOM strategy has been increasingly recognized, because it may reduce hospital stay and hospitalization costs, and avoid the risk of complications associated with non-therapeutic laparotomy^3,4,5. It has been reported that SNOM ....

Protocol

This study was approved by the Animal Ethics Subcommittee of the General Hospital of Northern Theater Command (Ethical Approval Number: 2024–23) and conducted in accordance with the ARRIVE guidelines (Animals in Research: Reporting In Vivo Experiments)¹⁶. All pigs were provided and maintained by the Laboratory Animal Center of the General Hospital of Northern Theater Command.

1. Grouping

1. Use 24 male Landrace pigs aged 4 months, with an average body weight of 27.7 kg and a range of 25–30 kg.
2. House each pig individually in a standard cage for at least 48 h before the e....

Results

In all 24 pigs, the vital signs remained stable within 1–2 h after modeling.

Gunshot injury model

In the immediate surgery group, all 6 pigs had penetrating injuries (Table 1). Surgical exploration revealed that 1 pig (16.67%) had a peritoneal penetration without organ injury, 1 (16.67%) a liver penetration injury, and 4 (66.67%) liver lacerations (Figure 3A). Two pigs (33.33%) underwent therapeutic lap.......

Discussion

According to the ballistic path, gunshot injuries can be classified into penetrating and blind tube injuries. Blast injuries are generally classified into four types: 1) damage caused solely by the explosive blast wave; 2) damage caused primarily by debris from the explosive device or the surrounding environment; 3) damage resulting from displacement of the victim or environmental structures; and 4) burns, poisoning, and radioactive contamination¹⁵. The present study simulated penetrating gunshot .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Adjustable single-channel pipette, 20–200 µL	Thermo Labsystems	4642080
AU5800 Series Clinical Chemistry Analyzers	Beckman Coulter	B23279
Automated Blood Coagulation Analyzer CS-5100	Sysmex	BY990757
BC-6800Plus Auto Hematology Analyzer	Mindray	BC-6800Plus
Cefuroxime Sodium for Injection, 0.75 g/vial	Guangzhou Baiyunshan Tianxin Pharmaceutical Co., Ltd.	NMPA approval No. H10940187
Coated braided silk suture	Covidien Healthcare International Trading (Shanghai) Co., Ltd.	N/A
Continuous dispenser	TOMOS Life Science Group	1008004
Convex array probe	SonoScape Medical Corp	Model 3C-A
Denley Dragon Wellscan MK-3 Microplate Reader	Thermo Labsystems	Wellscan MK-3
Digital-display water-jacketed electric thermostatic incubator	Shanghai Yuejin Medical Instrument Factory	PYX-DHS
Electric thermostatic blast drying oven	Shanghai Jinghong Experimental Equipment Co. Ltd.	DHG-9023A
Endotracheal Tube, Size 7.5 mm	Teleflex	5-10114
GEM Premier 3500 Blood Gas Analyzer	Werfen	26000000
High-speed tabletop centrifuge	Shanghai Anting Scientific Instrument Factory	TGL-168
K2 EDTA vacuum blood collection tube	Jiangsu Yuli Medical Instrument Co., Ltd.	N/A
Multifunctional animal trauma modeling platform	Chongqing Zhishangyun Technology Co., Ltd.	23X-FH
Porcine IL-10 Elisa Kit	Aimeng Youning	LV70245
Porcine IL-6 Elisa Kit	Aimeng Youning	LV70293
Porcine TNF-α Elisa Kit	Aimeng Youning	LV70500
Portable color Doppler ultrasound diagnostic system	SonoScape Medical Corp	Model E3
Preset heparinized arterial blood collection syringe	BD	364390
Propofol 1% (10 mg/mL)	Fresenius Kabi	N/A
RM800 Veterinary Multi-parameter Monitor	RWD Life Science Co., Ltd.	RM800
Safety closed IV catheter	Shandong Ande Healthcare Apparatus Co., Ltd.	N/A
Serum separator tube (SST), clot activator + gel	Jiangsu Yuli Medical Instrument Co., Ltd.	N/A
Sodium Chloride Injection 0.9%, 500 mL	Anhui BBCA Pharmaceutical Co., Ltd.	NMPA approval No. H34021876
SPSS	IBM Corp, Armonk, New York, USA	26
Sterile disposable syringe, 10 mL	Shandong Ande Healthcare Apparatus Co., Ltd.	N/A
Sterile disposable syringe, 5 mL	Shandong Ande Healthcare Apparatus Co., Ltd.	N/A
Sterile surgical forceps (straight and curved)
Sterilization wrapping sheet (non-woven fabric)	MPACK	A082700
Vacuum blood collection tube, sodium citrate	Jiangsu Yuli Medical Instrument Co., Ltd.	N/A
Vortex mixer	Shanghai Qingpu Huxi Instrument Factory	XW-80A
Wellwash 4 MK 2 Microplate Washer	Thermo Labsystems	N/A