Evaluation of the effects of ectopic replantation on amputate survival in the management of crush traumatic amputations in rats: An experimental study

Abstract

Background: This controlled experimental study aimed to compare ectopic replantation with other replantation techniques in a rat model of crush amputations. It also assessed the impact of different replantation methods on the viability of amputates.

Methods: Forty male Wistar albino rats were divided into four groups. Groin flaps served as the amputation model. Group 1 un-derwent guillotine-style amputation followed by orthotopic replantation, Group 2 experienced crush-type amputation and orthotopic replantation, Group 3 had crush-type amputation and orthotopic replantation with a vein graft, and Group 4 underwent crush-type amputation followed by ectopic replantation. Flap viability and perfusion rates were assessed on day 3 using an infrared perfusion as-sessment system. The ratio of viable area to total flap area and thrombus formation in the pedicle vessels were evaluated on day 7.

Results: Infrared evaluations on day 3 post-replantation revealed flap perfusion percentages of 73.5% in Group 1, 11.1% in Group 2, 65% in Group 3, and 64.1% in Group 4. Statistical analysis indicated that Group 1 exhibited the highest perfusion rates, while Group 2 showed the lowest. No differences were observed between Groups 3 and 4. On the seventh day, the average surviving flap areas were found to be 74.6% in Group 1, 2.5% in Group 2, 64.5% in Group 3, and 64% in Group 4. Statistically, Group 1 exhibited the best outcomes, while Group 2 had the poorest, with no differences between Groups 3 and 4. Additionally, thrombus formation was observed in the vessels of two animals in Group 1, nine in Group 2, and three each in Groups 3 and 4. Significant statistical differences were noted among the groups.

Conclusion: The results indicate that ectopic replantation and replantation with a vein graft are equally effective. The preferred method for crush-type replantations may depend on the patient's and the amputated limb's conditions. In crush-type amputations, we recommend vein graft repair if the patient's overall condition supports replantation and if crushed segments can be debrided without excessive shortening of the amputated part. If these conditions are not met, temporary ectopic replantation is advised to preserve the amputated limb.

Figure 1

Preoperative design of the left inguinal flap on a rat, showing delineated borders. X: Xiphoid Process; P: Pubic Bone; Dotted line: Iliac Ligament.

Figure 2

Harvesting of the left groin island flap. (a) The groin flap includes superficial epigastric vessels. (b) View of the flap harvested based on the superficial epigastric artery and vein (SEA and SEV).

Figure 3

Crush type amputation procedure. (a) Avulsion injury achieved by pulling mosquito clamps with silicone tubes placed in their jaws, applied in both proximal and distal directions. (b) Following the creation of a crush-type injury, amputation was performed using scissors (1. Proximal end of femoral vessels. 2. Crushed vascular segment showing thrombus due to avulsion).

Figure 4

Posterior facial vein graft harvesting in rats. (a) Naked eye view. (b) Microscopic view. * indicates the posterior facial vein.

Figure 5

Ectopic replantation. (a) Preoperative planning. (b) Mobilization of the advancement flap for donor site coverage. (c) Suturing of the advancement flap to the new location. (d) The ectopically replanted skin island covering the right inguinal region.

Figure 6

Determination of skin perfusion rate on day 3 with ICG-assisted infrared imaging system. The anterior abdominal wall served as a reference; perfusion percentage was averaged from the corners and the midpoint of the flap.

Figure 7

Determination of the percentage of living flap area using the Digimizer image analysis program.

Figure 8

Graphical representation of perfusion assessment results on day 3.

Figure 9

Examination of three rats from Group 4 on postoperative day 7. (a) View of complete flap viability. (b) View of partial flap viability. (c) Complete flap loss.