Original article
The analysis of the intrasurgical view of the obstetric brachial plexus palsy

Communicating author:
Jerzy Gosk, Department of Trauma and Hand Surgery Medical University of Wrocław, ul. R. Traugutta 57/59, 50-417 Wrocław, Poland,
tel. +48 71 370 02 12, fax +48 71 344 25 29, e-mail: chiruraz@churaz.am.wroc.pl

Introduction
The obstetric brachial plexus palsy occurs with the frequency from 0.35‰ to 5‰ [7,13,22]. In about 80% of cases the spontaneous, progressive recovery of the upper extremity function is observed due to rehabilitation, whereas in others the surgical intervention is necessary [6, 8, 10, 16]. Indications to the surgical treatment are established based on a detailed clinical examination and results of electromyography, myelography, myelo – KT and myelo – MR [12,20]. The decision about the character of the treatment should be taken about the third month of the child’s life, but yet at the very latest to the 6 month [2,9,18,21].

Material and methods
The clinical material consisted of 49 children with the obstetric brachial plexus palsy (28 boys, 21 girls) treated surgically (Department of Trauma and Hand Surgery, Medical University of Wrocław), in the period of 1999-2003. The age of the children at the moment of operation was: to 3 months – 11 cases, from 3 to 6 months – 16 cases, from 6 to 12 months – 8 cases, more than 12 months – 14 cases. The intrasurgical view and the applied microsurgical techniques were analysed.

Results
Intrasurgically, we found: A – compression of the brachial plexus due to proliferation of the fibrous tissue (with continuity of the elements of the brachial plexus) – 21 cases, B – injuries with discontinuity of the elements of the brachial plexus – 28 cases. The character of the injuries with the discontinuity of the brachial plexus is shown in table I. Localization of the rupture injuries is shown in table II. Localization of the avulsion lesions is presented in table III. The following surgical procedures were carried out during treatment: neurolysis – 31 cases, reconstruction (direct neurorrhaphy) – 7 cases, reconstruction (2-4 sural nerve grafting from 2 to 3 cm) – 4 cases, extranatomical extraplexual reconstruction (neurotisation) – 6 cases, extraanatomical intraplexual reconstruction – 1 case.

Discussion
In all cases the intrasurgical view motivated the operative intervention. The compression of the brachial plexus due to proliferation of the fibrous tissue was observed in 21 cases – fig. 1a, b. The neurolysis allowed to accelerate the regeneration process and the prognosis in this type of lesions is good [4,17]. Injuries with discontinuity of the elements of the brachial plexus require microsurgical reconstruction in the first months of the child’s life [4,16,18,21]. In this group, the age of the treated surgically children varies from 2 to 6 months, and only in two cases the operations were delayed (9 months, 3 years). In cases of brachial plexus trunks ruptures the continuity of the neural elements was reconstructed with direct neurorrhaphy or sural nerve grafting [4] – fig. 2a, b. The particular kind of lesion is rupture of the trunk with secondary, spontaneous reinnervation. Usually, this process has a correct direction. However, in some cases the course of the reinervation may be chaotic. The secondary reinervation of the antagonistic groups of muscles from the one source is in danger and can lead to synkinesis (co-contractions) [1,3]. In our own material we observed 11 cases of spontaneous recovery after rupture of the neural trunks. The most frequent localization was the superior trunk – fig. 3. The surgical treatment consisted in delicate neurolysis and then in an assessment of the conductivity after intrasurgical electrical stimulation. The correct motor reaction in the muscles confirmed the rightness of the used surgical procedure. The preganglionic injuries like spinal nerve roots avulsion are a difficult diagnostic and therapeutical problem – fig. 4 a, b. The avulsed spinal nerve may be pulled out from the intervertebral foramen or stay intraforaminally [5,15,19]. In the first situation, ventral (motor) and dorsal (sensory) roots of the spinal nerve could be identified, which allowed to perform a selective neurotisation [14]. In the second situation, the decision about resection of the remaining intraforaminally, most probably avulsed, spinal nerve or leaving it should be taken. This kind of decision ought to be taken based on the preoperative clinical examination and electromyography, imaging diagnostics (the possibility of false – positive findings), intrasurgical exams (electrical stimulation, SEP) and also evaluation of the tension of neural elements [11]. The preganglionic lesions have a significantly worse prognosis, but they are rather rare. In our own material their frequency was 14.3% (7 from 49 cases) and they include avulsion from 1 to 4 spinal nerve mainly C5, C6, C7. High percentage of these spinal nerves avulsion was observed in the other authors’ materials [5,19]. Reconstructions in the perinatal brachial plexus palsy need experience and master microsurgical techniques. They are performed under the microscope with the use of the suture material 8–10/0. The most important problem in treatment of the obstetric brachial plexus palsy is a separate group of children who need surgical intervention.

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