High-Definition Video System for Peripheral Neurorrhaphy in Rats

End-to-side neurorrhaphy in the reconstruction of peripheral segmental neural loss: an experimental study

PURPOSE

To evaluate the effects on peripheral neural regeneration of the end-to-side embracing repair technique compared to the autograft repair technique in Wistar rats.

METHODS

Fifteen male Wistar rats were divided into three groups with five animals each: denervated group (GD), autograft group (GA), and embracing group (EG). For the evaluation, the grasping test, electroneuromyography (ENMG), and muscle weight assessment were used.

RESULTS

Muscle weight assessment and ENMG did not show significant neural regeneration at the end of 12 weeks in the DG and GE groups, but only in GA. The grasping test showed an increase in strength between the surgery and the fourth week in all groups, and only the GA maintained this trend until the 12th week.

CONCLUSIONS

The present study indicates that the neural regeneration observed in the end-to-side embracing neurorrhaphy technique, in the repair of segmental neural loss, is inferior to autograft repair in Wistar rats.

A realistic model for vasectomy reversal training using swine testicles

PURPOSE

To evaluate the viability of the porcine vas deferens as a realistic microsurgical training model for vasectomy reversal.

METHODS

The model uses swine testicles (vas deferent), which are usually discarded in large street markets since they are not part of Brazilian cuisine. The spermatic cord was carefully dissected, and the vas deferens were isolated, measuring 10 cm in length. A paper quadrilateral with 5 cm2 was built to delimit the surgical training field. The objective of the model is to simulate only the microsurgical step when the vas deferens are already isolated. The parameters analyzed were: feasibility for reproducing the technique, patency before and after performing the vasovasostomy, cost of the model, ease of acquisition, ease of handling, execution time, and model reproducibility.

RESULTS

The simulator presented low cost. All models made were viable with a texture similar to human, with positive patency obtained in 100% of the procedures. The internal and external diameters of the vas deferens varied between 0.2-0.4 mm and 2-3 mm, respectively, with a mean length of 9 ± 1.2 cm. The total procedure time was 43.28 ± 3.22 minutes.

CONCLUSIONS

The realistic model presented proved to be viable for carrying out vasectomy reversal training, due to its low cost, easy acquisition, and easy handling, and providing similar tissue characteristics to humans.

Low cost and easy acquisition: corn grain in microsurgery training

OBJECTIVES

develop an easily accessible model for training the initial motor practice in microsurgery using corn kernels.

METHODS

ten corn kernels (Zea mays) were used. A 7mm longitudinal cut was made on one side of the corn grain. The training consisted of performing 4 simple knots between the edges of the incision, using 10-0 mononylon thread. The parameters analyzed were 1) cost of the model; 2) assembly time of the model test system; 3) time for performing the knots; 4) distance between the knots.

RESULTS

in all corn kernels tested, it was possible to perform the proposed microsurgical suture training, without any difficulty in the procedure. The average time to perform the 4 knots was 6.51±1.18 minutes. The total cost of the simulator model was R$3.59. The average distance between the knots was 1.7±0.3mm. The model developed from corn grains has an extremely low cost when compared to the use of animals or high-tech simulators. Other advantages are the easy availability of canned corn kernels and the possibility of making more than four knots along the 7mm incision.

CONCLUSION

the training model developed has low cost, is easy to acquire and viable for training basic manual skills in microsurgery.

Anatomorphometry of the brachial plexus under high-definition system: an experimental study in rats

PURPOSE

To study the anatomorphometry of the plexus brachialis (PB) of rats under a high-definition video system.

METHODS

Ten male Wistar rats discarded from other research that did not interfere in the morphology of the animal, respecting the principle of reduction, were used. All animals were submitted to the same protocol. Initially, the cervical region was shaved. The animals were placed in a dorsal position. A single elbow-to-elbow incision was performed and dissection started at the deltopectoral sulcus. The procedures were performed under a video system. To measure the structures, the Image J software was used.

RESULTS

All the PB evaluated originated from the C5-T1 spinal nerves. C5 and C6 converged to form the truncus superior, the root of C7 originated the truncus medius, and the confluence of C8 and T1 originated the truncus inferior. It was found the union of C7, C8, and T1 to form truncus inferomedialis instead of separate medial and inferior truncus. C8 (1.31 mm) was the thickest root, the truncus inferior (1.80 mm) and the nerve radialis (1.02 mm), were the thickest.

CONCLUSIONS

The anatomy of the PB is comparable to humans, admitting variations. The videomagnification system is useful to perform microsurgical dissection.

A comparison of using a smartphone versus a surgical microscope for microsurgical anastomosis in a non-living model

Background

Although they may not replace standard training methods that use surgical microscopes, smartphones equipped with high-resolution screens and high-definition cameras are an attractive alternative for practicing microsurgical skills. They are ubiquitous, simple to operate, and inexpensive. This study compared anastomoses of chicken femoral vessels using a smartphone camera versus a standard operative microscope.

Methods

Forty anastomoses of non-living chicken femoral vessels were divided into four groups. A resident and an experienced microsurgeon performed anastomoses of femoral chicken vessels with 8-0 and 10-0 sutures, using a smartphone camera and a surgical microscope. The time to complete the anastomosis and the number of anastomosis errors were compared using the Mann-Whitney U test.

Results

The time taken to perform an anastomosis by the experienced microsurgeon was significantly longer when using the smartphone (median: 32.5 minutes vs. 20 minutes, P<0.001). The resident completed the anastomoses with both types of equipment without a significant difference in the operative times. When using a smartphone, the operation times were not significantly different between the resident and the experienced microsurgeon (P=0.238). The resident showed non-significant differences in operation time and the number of errors when using a smartphone or an operative microscope (P=1.000 and P=0.065, respectively).

Conclusions

Microsurgical practice with non-living chicken femoral vessels can be performed with a smartphone, though it can take longer than with an operative microscope for experienced microsurgeons. The resident may also experience frustration and tend to make more anastomosis errors when using a smartphone versus an operative microscope.

Baixo custo e fácil aquisição: grãos de milho no treinamento microcirúrgico

RESUMO Objetivo: desenvolver um modelo facilmente acessível para o treinamento da prática motora inicial em microcirurgia a partir da utilização de grãos de milho. Métodos: foram utilizados dez grãos de milho (Zea mays). Realizou-se um corte longitudinal de 7mm em uma das faces do grão de milho. O treinamento consistiu na realização de 4 pontos simples entre as bordas da incisão, utilizando fio de mononáilon 10-0. Os parâmetros analisados foram 1) custo do modelo; 2) tempo de montagem do sistema de teste do modelo; 3) tempo de realização dos nós; 4) distância entre os pontos. Resultados: em todos os grãos testados foi possível realizar o treinamento de sutura microcirúrgica proposto, sem dificuldade ao procedimento. O tempo médio para a realização dos 4 pontos foi de 6,51±1,18 minutos. O custo total do modelo simulatório foi de R$3,59. A distância média entre os pontos foi de 1,7±0,3mm. O modelo desenvolvido a partir de grãos de milhos apresenta custo extremamente baixo quando comparado ao uso de animais ou de simuladores de alta tecnologia. Outras vantagens são fácil disponibilidade de grãos de milho em conserva e possibilidade de serem realizados mais de quatro pontos ao longo da incisão de 7mm. Conclusão: o modelo de treinamento desenvolvido é de baixo custo, de fácil aquisição e viável para o treinamento de habilidades manuais básicas em microcirurgia.

Criteria for assessing peripheral nerve injury. Behavioral and functional assessment in non-operated Wistar rats

Purpose

To evaluate the normality pattern in functional tests of peripheral nerves.

Methods

Sixty female and sixty male Wistar rats were submitted to vibrissae movement and nictitating reflex for facial nerve; grooming test and grasping test for brachial plexus; and walking tracking test and horizontal ladder test for lumbar plexus. The tests were performed separately, with an interval of seven days between each.

Results

All animals showed the best score in vibrissae movement, nictitating reflex, grooming test, and horizontal ladder test. The best score was acquired for the first time in more than 90% of animals. The mean of strength on the grasping test was 133.46±12.08g for the right and 121.74±8.73g for the left anterior paw. There was a difference between the right and left sides. There was no difference between the groups according to sex. There is no statistical difference comparing all functional indexes between sex, independent of the side analyzed. The peroneal functional index showed higher levels than the sciatic and tibial functional index on both sides and sex.

Conclusions

The behavioral and functional assessment of peripheral nerve regeneration are low-cost, easy to perform, and reliable tests. However, they need to be performed by experienced researchers to avoid misinterpretation.

Can Smartphones Be Used to Perform Video-Assisted Microanastomosis? An Experimental Study

BACKGROUND

Smartphone cameras are continuously improving. The present study aimed to evaluate the possibility of using smartphones' magnification system to perform microanastomosis in rats.

METHODS

Fifteen rats were randomly divided into 3 groups, according to the magnification system used: Microscope, iPhone 7 smartphone, and Galaxy S7 smartphone. In the microscope group, a DFVasconcelos microsurgery microscope was used. In both smartphone groups, the magnifications systems were connected to a 55-inch television through the mirror function. Animals in both groups underwent femoral artery anastomosis in the right forepaw and femoral nerve neurorrhaphy in the left hindleg. The body weight, arterial and nerve caliber, and anastomosis time and patency were immediately analyzed.

RESULTS

No significant differences were observed between the groups regarding body weight, arterial, or nerve caliber. The smartphones did not provide a sufficient quality of image for an adequate identification of the arterial walls. Therefore, neither arterial anastomosis nor neurorrhaphy could be completed, even after 3 hours of surgery. The first steps toward anastomosis or raffia were performed with difficulty.

CONCLUSION

The current video resolution and lack of stereoscopic image of available smartphones is not sufficient to perform video-assisted anastomosis of femoral arteries or nerves.

Does the type of electrode affect the electromyoneurographic parameters in rats?1

Purpose

To evaluate if the type of electrode (needle vs. surface) affects the electromyoneurography parameters in rats.

Methods

Twenty male rats were anesthetized, then compound muscle action potential were recorded using a Neuropack S1 MEB- 9400^©. All animals were submitted to two electroneuromyography analysis: first with surface electrode and then by needle electrode. We evaluated the latency, amplitude, duration and area of the negative peak of the gastrocnemius and cranial tibial muscles.

Results

There were no significant differences between the groups in the mean of duration, latency, amplitude or area of the negative peak in gastrocnemius and cranial tibial muscles.

Conclusion

The type of electrode does not affect the electroneuromyography parameters.