COVID-19 lockdown and beyond: Home practice solutions for developing microsurgical skills.

Dear Sir,

Current COVID-19 restrictions present significant challenges to Plastic Surgery training. Numerous obstacles exist; including the necessity for social distancing, global PPE shortages, virtual clinics decreasing trainee exposure to pathology, reduced face-to-face clinical teaching, and limited time in theatre. Furthermore, suspension of non-urgent elective reconstruction work, including breast reconstruction, limits microsurgical training opportunities. Surgical training relies on multiple sequential practice sessions, to allow deep encoding into "muscle memory”, this is particularly relevant for microsurgery where fine motor skills need to be developed.

The authors present multiple practical and cost-effective solutions that allow trainees to practice microsurgical techniques from home and “upskill anywhere”. These practice options are transferrable to other periods away from clinical practice, including research time and maternity leave, and can also be used to supplement clinical experience during unpredictable on-call rotas. In climates of economic instability, these techniques may prove particularly beneficial.

A basic microsurgical instrument kit may be purchased online from multiple platforms at a relatively low cost (e.g. AliEx-press™, £34). The cost of microsurgical sutures can be a limiting factor to microsurgical practice (e.g. 9.0 AliExpress™, £0.93 each) and in the context of the COVID-19 pandemic, precarious supply chains necessitate preservation of resources. Luangjarmekorn et al. describe the use of human hair and insulin needles (BD Ultra-Fine Pen Needles 4 mm × 32 G, expresschemist.co.uk, £0.13 each) to make homemade microsurgical sutures (Table 1 ). Feedback from trainees in their study suggested that human hair sutures (Figure 1 ) was a “good-excellent” standard for microsurgical practice, equal to that of standard sutures. This is reflected in our experience; we find that a hair of dark colour, mid length, coarse texture and wavy consistency works best.

Table 1

How to make a homemade microsurgical suture.

What you need: Insulin pen needle (eg BD Ultra-Fine Pen Needles 4 mm × 32 G) Human hair (ideally dark in colour, mid length and wavy/coarse texture) Microforceps Fine smooth pliers Loupe magnification Scissors

How to: Set up a light source (eg balance phone with torch on, on top of loupes/insulin needle box) Remove wrapper from insulin pen needle Don loupes Identify hair follicle end of hairExcise hair follicle with scissors Thread the hair through the insulin needle, follicle end first, using the micro forceps until 5 mm of hair protrudes through the needle Use fine smooth pliers to compress needle around hair proximally and form a smooth curve distally Cut off 5 mm of protruding hair from distal end Use smooth pliers to remove suture from insulin pen needle casing

Fig. 1

a) Flower petal model b) Microtrainer™ model test strip, scoring 29/35 c) Homemade suture made from insulin pen needle and human hair d) 9.0 Ethilon™ suture e) 11.0 Ethilon™ suture.

There are multiple models for microsurgical practice described in the literature, including live animal models (predominantly rats), non-live animal models such as chicken wings or thighs, pig leg, placenta vessels, and cold stored vessels. Additionally, a number of non animal models exist including, rubber glove, gauze, silicone tubing and fresh leaves. All have specific advantages and disadvantages.

Many courses, including the Canniesburn Microsurgery Masterclass (https://www.nhsggc.org.uk/about-us/professional-support-sites/canniesburn-plastic-surgery-and-burns-unit/courses-at-canniesburn/microsurgical-workshop/) feature live animal models, which may better simulate real life microsurgery and allow testing of anastomosis patency and flow. A bag of saline infused with blue food colouring, running at a rate of 10 drops per minute (Zeng et al.) may be considered as a method of anastomosis testing in other models. For home practice, the authors favour non animal models, due to ease of access, cost effectiveness, infection control and compliance with the “3R principles” in accordance with the National Centre for the Replacement, Reduction and Refinement of Animals in Research.

We describe the use of a novel flower petal model (Figure 1) as it is readily available, requires meticulous handling and poses minimal environmental impact. Simple analysis scripts on open source image analysis software such as FIJI™ (Fiji.sc) can be utilised to analyse microsurgical suture placement. Another alternative model favoured by our group is the use of silicone tubing (Pocket Suture™, £9) or a MicroTrainer strip (DigitalSurgicalSkillsAcademy™).

The key benefit of the MicroTrainer™ and accompanying software/app is that it provides objective assessment of accuracy of suture spacing, orientation and progress over time. This method is currently used in the RCSEd microsurgical skills course (https://www.rcsed.ac.uk/events-courses/event-entry?diaryId=2712).

In our department, we have been running supplementary microsurgery training sessions by senior trainees and consult-ants, using microscopes and screens to allow for social distancing. The use of social media, such as the International Microsurgery Club (Tang et al.) can also provide peer learning and communication with experts in the microsurgical community, whilst working remotely.

Therefore; there are many innovative, low-cost options for suture material, microsurgery models, and assessment of microsurgical skill progression. These solutions may be utilised to develop microsurgical skills during periods of remote working.