Rat Microvascular Model is Tolerant to Technical Errors

Abstract

Background Extensive studies have been conducted using the rat model to understand the potential technical errors that lead to anastomotic failure. However, current literature indicates that the rat model has excellent tolerance to diverse errors committed by microsurgeons. The error-investigating rat model is often created by one or two experienced surgeons, and only one isolated technical error is examined. These biases may potentially cause limitations of the results from previous studies. Meanwhile, venous anastomoses have rarely been investigated in previous literature. Therefore, it is important to elucidate this topic with a more comprehensive study design.

Methods Ninety-four arterial and 94 venous anastomoses on Sprague–Dawley rat femoral vessels that were performed by 47 microsurgeons who participated in the microsurgery course at the Columbia University and the University of Thessaloniki were evaluated. In total, 10 technical errors were examined: (1) disruption of suture line, (2) back-wall stitch, (3) oblique stitch, (4) wide bite, (5) partial thickness bite, (6) unequal suture distance, (7) tear in vessel wall, (8) excessively tight suture, (9) suture threads in lumen, and (10) large edge overlap. The frequency of each error committed, and the 30-minute postoperative patency was also recorded. The underlying causal relationship between these errors, potential interaction, and the short-term anastomosis patency was analyzed statistically.

Results Only the back-wall stitch was found to have a significant causal effect on arterial anastomosis failure (p < 0.001). Back-wall stitch, wide bite, and partial thickness bite significantly impact venous anastomosis patency (p < 0.001). No other statistically significant result was found.

Conclusion Overall, the rat model is highly resilient to various technical errors despite these mistakes being often considered clinically unacceptable. Therefore, researchers need to consider the resilience of the rat model when designing and analyzing future studies. In addition, microsurgery instructors should focus on individual stitch quality rather than the final patency.

Keywords

microsurgery training - microsurgery errors - rat model in microsurgery

Note

This study was presented at the Plastic Surgery The Meeting 2021 in Atlanta, Georgia.[29]

^* These authors contributed equally to this work.

Publication History

Received: 06 May 2023

Accepted: 13 July 2023

Accepted Manuscript online:
14 August 2023

Article published online:
26 September 2023

• References

• 1 Ghanem A, Kearns M, Ballestín A. et al. International microsurgery simulation society (IMSS) consensus statement on the minimum standards for a basic microsurgery course, requirements for a microsurgical anastomosis global rating scale and minimum thresholds for training. Injury 2020; 51 (Suppl. 04) S126-S130
• 2 MacDonald JD. Learning to perform microvascular anastomosis. Skull Base 2005; 15 (03) 229-240
• 3 Decherd ME, Calhoun KH. The effect of tension on patency of rat femoral artery anastomoses. Arch Facial Plast Surg 2003; 5 (01) 83-85
• 4 Chow SP, Huang CD, Chan CW. Microvascular anastomosis of arteries under tension. Br J Plast Surg 1982; 35 (01) 82-87
• 5 Topalan M, Bilgin SS, Ip WY, Chow SP. Effect of torsion on microarterial anastomosis patency. Microsurgery 2003; 23 (01) 56-59
• 6 Levi MA, Harb AA, Nicolas CF. et al. Torsion is tolerated in arterial end to venous side anastomoses in the rat model. J Reconstr Microsurg 2020; 36 (07) 501-506
• 7 Harb A, Levi M, Kozato A, Akelina Y, Strauch RJ. Torsion does not affect early vein graft patency in the rat femoral artery model. J Reconstr Microsurg 2019; 35 (04) 299-305
• 8 Nasir S, Aydin MA, Altuntaş S, Ozgüner M. Thrombotic effect of purposeful back-wall stitch for end-to-side microarterial anastomosis in rats. J Reconstr Microsurg 2008; 24 (06) 429-433
• 9 Nasir S, Aydin MA, Ozgüner M. Thrombotic effect of purposeful back-wall stitch for different suture locations and vessels in rats. Ann Plast Surg 2005; 55 (05) 508-511
• 10 Pignatti M, Benati D, Cavadas PC. Effect of the two-wall-stitch mistake upon patency of rat femoral vein anastomosis: preliminary observations. Microsurgery 2004; 24 (04) 339-344
• 11 Zheng YD, Nicolas CF, Corvi JJ. et al. Large and uneven bites in end-to-end anastomosis of the rat femoral artery. J Reconstr Microsurg 2020; 36 (07) 486-493
• 12 Wong AK, Joanna Nguyen T, Peric M. et al. Analysis of risk factors associated with microvascular free flap failure using a multi-institutional database. Microsurgery 2015; 35 (01) 6-12
• 13 Suominen S, Asko-Seljavaara S. Free flap failures. Microsurgery 1995; 16 (06) 396-399
• 14 Harashina T. Analysis of 200 free flaps. Br J Plast Surg 1988; 41 (01) 33-36
• 15 Khouri RK. Free flap surgery. The second decade. Clin Plast Surg 1992; 19 (04) 757-761
• 16 Khouri RK. Avoiding free flap failure. Clin Plast Surg 1992; 19 (04) 773-781
• 17 Novakovic D, Patel RS, Goldstein DP, Gullane PJ. Salvage of failed free flaps used in head and neck reconstruction. Head Neck Oncol 2009; 1 (01) 33
• 18 Paladino JR, Gasteratos K, Akelina Y, Marshall B, Papazoglou LG, Strauch RJ. The benefits of expert instruction in Microsurgery Courses. J Reconstr Microsurg 2021; 37 (02) 143-153
• 19 Cooley BC. A Laboratory Manual for Microvascular and Microtubal Surgery. 2nd ed.. Philadelphia, PA: Surgical Specialties Corporation; 2009: 10-11 , 39–59
• 20 Ghanem AM, Al Omran Y, Shatta B, Kim E, Myers S. Anastomosis Lapse Index (ALI): a validated end product assessment tool for simulation microsurgery training. J Reconstr Microsurg 2016; 32 (03) 233-241
• 21 Khouri RK, Cooley BC, Kunselman AR. et al. A prospective study of microvascular free-flap surgery and outcome. Plast Reconstr Surg 1998; 102 (03) 711-721
• 22 Yii NW, Evans GR, Miller MJ. et al. Thrombolytic therapy: what is its role in free flap salvage?. Ann Plast Surg 2001; 46 (06) 601-604
• 23 Nakatsuka T, Harii K, Asato H. et al. Analytic review of 2372 free flap transfers for head and neck reconstruction following cancer resection. J Reconstr Microsurg 2003; 19 (06) 363-368 , discussion 369
• 24 Bui DT, Cordeiro PG, Hu Q-Y, Disa JJ, Pusic A, Mehrara BJ. Free flap reexploration: indications, treatment, and outcomes in 1193 free flaps. Plast Reconstr Surg 2007; 119 (07) 2092-2100
• 25 Benacquista T, Kasabian AK, Karp NS. The fate of lower extremities with failed free flaps. Plast Reconstr Surg 1996; 98 (05) 834-840 , discussion 841–842
• 26 Khouri RK, Shaw WW. Reconstruction of the lower extremity with microvascular free flaps: a 10-year experience with 304 consecutive cases. J Trauma 1989; 29 (08) 1086-1094
• 27 Kleinert HE, Jablon M, Tsai TM. An overview of replantation and results of 347 replants in 245 patients. J Trauma 1980; 20 (05) 390-398
• 28 Cuteanu A, Hellich A, Cardinal AL. et al. Microsurgery Training Group at The Griffin Institute.. Evaluation of a microsurgery training curriculum. J Reconstr Microsurg 2023; 39 (08) 589-600
• 29 Zheng Y, Paladino JR, Gasteratos K. et al. A comprehensive investigation of the effect of technical errors in microsurgical anastomotic patency in the rat model. Plast Reconstr Surg Glob Open 2021; 9 (10S): 127