Mario G Siqueira

Publications (14)22.35 Total impact

• Article: Efficacy and Safety of Oberlin's Procedure in the Treatment of Brachial Plexus Birth Palsy.

  Mario G Siqueira, Mariano Socolovsky, Carlos Otto Heise, Roberto S Martins, Gilda Di Masi
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  ABSTRACT: BACKGROUND:: In brachial plexus injuries, when there are no available roots to use as a source for graft reconstruction, nerve transfers emerge as an elective technique. For this purpose, transfer of an ulnar nerve fascicle to the biceps motor branch (Oberlin's procedure) is often used. Despite the high rate of good to excellent results in adults, this technique is seldom used in children. OBJECTIVE:: To evaluate the efficacy and safety of Oberlin's procedure in the surgical treatment of brachial plexus birth palsy. METHODS:: Striving to restore elbow flexion, we performed Oberlin's procedure on seventeen infants with brachial plexus birth palsy. After follow-up of at least 19 months, primary outcomes were the strength of elbow flexion (modified British Medical Research Council Scale), hand function measured using Al-Qattan's Scale, and comparative X-rays of both hands to detect altered growth. RESULTS:: Good to excellent results related to biceps contraction were obtained in fourteen patients (82.3%) (3/MRC3, 11/MRC4). The preoperative Al-Qattan's score for the hand was maintained at final follow-up. Comparing the treated and normal limb, no difference was observed in hand development by X-ray. CONCLUSION:: Oberlin's procedure is an effective and safe option for the surgical treatment of upper brachial plexus birth palsy.
  Neurosurgery 10/2012; · 2.79 Impact Factor
• Article: Management of desmoid-type fibromatosis involving peripheral nerves.

  Mario G Siqueira, Paulo L Tavares, Roberto S Martins, Carlos O Heise, Luciano H L Foroni, Marcelo Bordalo, Roberto Falzoni
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  ABSTRACT: Desmoid-type fibromatosis is an uncommon and aggressive neoplasia, associated with a high rate of recurrence. It is characterized by an infiltrative but benign fibroblastic proliferation occurring within the deep soft tissues. There is no consensus about the treatment of those tumors. We present a surgical series of four cases, involving the brachial plexus (two cases), the median nerve and the medial brachial cutaneous nerve. Except for the last case, they were submitted to multiple surgical procedures and showed repeated recurrences. The diagnosis, the different ways of treatment and the prognosis of these tumoral lesions are discussed. Our results support the indication of radical surgery followed by radiotherapy as probably one of the best ways to treat those controversial lesions.
  Arquivos de neuro-psiquiatria 07/2012; 70(7):514-9. · 0.55 Impact Factor
• Article: Surgical treatment of adult traumatic brachial plexus injuries: an overview.

  Mario G Siqueira, Roberto S Martins
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  ABSTRACT: Traumatic injuries to the brachial plexus in adults are severely debilitating. They generally affect young individuals. A thorough understanding of the anatomy, clinical evaluation, imaging and electrodiagnostic assessments, treatment options and proper timing of surgical interventions will enable nerve surgeons to offer optimal care to patients. Advances in microsurgical technique have improved the outcome for many of these patients. The treatment options offer patients with brachial plexus injuries the possibility of achieving elbow flexion, shoulder stability with limited abduction and the hope of limited but potentially useful hand function.
  Arquivos de neuro-psiquiatria 06/2011; 69(3):528-35. · 0.55 Impact Factor
• Article: Fascicular topography of the suprascapular nerve in the C5 root and upper trunk of the brachial plexus: a microanatomic study from a nerve surgeon's perspective.

  Mario G Siqueira, Luciano H L Foroni, Roberto S Martins, Gerson Chadi, Martijn J A Malessy
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  ABSTRACT: In patients with supraclavicular injuries of the brachial plexus, the suprascapular nerve (SSN) is frequently reconstructed with a sural nerve graft coapted to C5. As the C5 cross-sectional diameter exceeds the graft diameter, inadequate positioning of the graft is possible. To identify a specific area within the C5 proximal stump that contains the SSN axons and to determine how this area could be localized by the nerve surgeon, we conducted a microanatomic study of the intraplexal topography of the SSN. The right-sided C5 and C6 roots, the upper trunk with its divisions, and the SSN of 20 adult nonfixed cadavers were removed and fixed. The position and area occupied by the SSN fibers inside C5 were assessed and registered under magnification. The SSN was monofascicular in all specimens and derived its fibers mainly from C5. Small contributions from C6 were found in 12 specimens (60%). The mean transverse area of C5 occupied by SSN fibers was 28.23%. In 16 specimens (80%), the SSN fibers were localized in the ventral (mainly the rostroventral) quadrants of C5, a cross-sectional area between 9 o'clock and 3 o'clock from the surgeon's intraoperative perspective. In reconstruction of the SSN with a sural nerve graft, coaptation should be performed in the rostroventral quadrant of C5 cross-sectional area (between 9 and 12 o'clock from the nerve surgeon's point of view in a right-sided brachial plexus exploration). This will minimize axonal misrouting and may improve outcome.
  Neurosurgery 12/2010; 67(2 Suppl Operative):402-6. · 2.79 Impact Factor
• Article: Phrenic nerve transfer in the restoration of elbow flexion in brachial plexus avulsion injuries: how effective and safe is it?

  Mario G Siqueira, Roberto S Martins
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  ABSTRACT: Phrenic nerve transfer has been used for treating lesions of the brachial plexus since 1970. Although, today, surgeons are more experienced with the technique, there are still widespread concerns about its effects on pulmonary function. This study was undertaken to evaluate the effectiveness and safety of this procedure. Fourteen patients with complete palsy of the upper limb were submitted to phrenic nerve transfer as part of a strategy for surgical reconstruction of their plexuses. Two patients were lost to follow-up, and 2 patients were followed for less than 2 years. Of the remaining 10 patients, 9 (90%) were male. The lesions affected both sides equally. The mean age of the patients was 24.8 years (range, 14-43 years), and the mean interval from injury to surgery was 6 months (range, 3-9 months). The phrenic nerve was always transferred to the musculocutaneous nerve, and a nerve graft (mean length, 8 cm; range, 4.5-12 cm) was necessary in all cases. There was no major complication related to the surgery. Seven patients (70%) recovered functional level biceps strength (Medical Research Council grade >or=3). All of the patients exhibited a transient decrease in pulmonary function tests, but without clinical respiratory problems. On the basis of our small series and data from the literature, we conclude that phrenic nerve transfer in well-selected patients is a safe and effective procedure for recovering biceps function.
  Neurosurgery 10/2009; 65(4 Suppl):A125-31. · 2.79 Impact Factor
• Article: Motor nerve-conduction studies in obstetric brachial plexopathy for a selection of patients with a poor outcome.

  Carlos O Heise, Mario G Siqueira, Roberto S Martins, José Luiz D Gherpelli
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  ABSTRACT: The criteria and timing for nerve surgery in infants with obstetric brachial plexopathy remain controversial. Our aim was to develop a new method for early prognostic assessment to assist this decision process. Fifty-four patients with unilateral obstetric brachial plexopathy who were ten to sixty days old underwent bilateral motor-nerve-conduction studies of the axillary, musculocutaneous, proximal radial, distal radial, median, and ulnar nerves. The ratio between the amplitude of the compound muscle action potential of the affected limb and that of the healthy side was called the axonal viability index. The patients were followed and classified in three groups according to the clinical outcome. We analyzed the receiver operating characteristic curve of each index to define the best cutoff point to detect patients with a poor recovery. The best cutoff points on the axonal viability index for each nerve (and its sensitivity and specificity) were <10% (88% and 89%, respectively) for the axillary nerve, 0% (88% and 73%) for the musculocutaneous nerve, <20% (82% and 97%) for the proximal radial nerve, <50% (82% and 97%) for the distal radial nerve, and <50% (59% and 97%) for the ulnar nerve. The indices from the proximal radial, distal radial, and ulnar nerves had better specificities compared with the most frequently used clinical criterion: absence of biceps function at three months of age. The axonal viability index yields an earlier and more specific prognostic estimation of obstetric brachial plexopathy than does the clinical criterion of biceps function, and we believe it may be useful in determining surgical indications in these patients.
  The Journal of Bone and Joint Surgery 07/2009; 91(7):1729-37. · 3.27 Impact Factor
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  Available from: socolovsky.com

  Article: Hemihypoglossal-facial neurorrhaphy after mastoid dissection of the facial nerve: results in 24 patients and comparison with the classic technique.

  Roberto S Martins, Mariano Socolovsky, Mario G Siqueira, Alvaro Campero
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  ABSTRACT: Hypoglossal-facial neurorrhaphy has been widely used for reanimation of paralyzed facial muscles after irreversible proximal injury of the facial nerve. However, complete section of the hypoglossal nerve occasionally results in hemiglossal dysfunction and interferes with swallowing and speech. To reduce this morbidity, a modified technique with partial section of the hypoglossal nerve after mastoid dissection of the facial nerve (HFM) has been used. We report our experience with the HFM technique, retrospectively comparing the outcome with results of the classic hypoglossal-facial neurorrhaphy. A retrospective review was performed in 36 patients who underwent hypoglossal-facial neurorrhaphy with the classic (n = 12) or variant technique (n = 24) between 2000 and 2006. Facial outcome was evaluated with the House-Brackmann grading system, and tongue function was evaluated with a new scale proposed to quantify postoperative tongue alteration. The results were compared, and age and time between nerve injury and surgery were correlated with the outcome. There was no significant difference between the two techniques concerning facial reanimation. A worse outcome of tongue function, however, was associated with the classic technique (Mann-Whitney U test; P < 0.05). When HFM was used, significant correlations defined by the Spearman test were identified between preoperative delay (rho = 0.59; P = 0.002) or age (rho = 0.42; P = 0.031) and results of facial reanimation evaluated with the House-Brackmann grading system. HFM is as effective as classic hypoglossal-facial neurorrhaphy for facial reanimation, and it has a much lower morbidity related to tongue function. Better results are obtained in younger patients and with a shorter interval between facial nerve injury and surgery.
  Neurosurgery 09/2008; 63(2):310-6; discussion 317. · 2.79 Impact Factor
• Article: Clinical-electromyography correlation in infants with obstetric brachial plexopathy.

  Carlos O Heise, Mario G Siqueira, Roberto S Martins, José Luiz D Gherpelli
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  ABSTRACT: The real utility of needle electromyography (EMG) for evaluation of infants with obstetric brachial plexopathy remains controversial. The objective of this paper is to evaluate how EMG correlates with clinical evaluation of these patients. We performed EMG in 41 infants (42 arms) with severe obstetric brachial plexopathy who were from 3 to 12 months of age. We correlated the EMG interference pattern with the clinical assessment of infraspinatus, deltoid, biceps, triceps, and extensor digitorum communis muscles. Motor unit potentials were always present, and abnormal spontaneous activity was not common in proximal muscles. The correlation between EMG interference pattern and clinical assessment was not good, except for extensor digitorum communis. EMG showed higher scores than clinical evaluation for infraspinatus, deltoid, and biceps muscles. Respiratory synkinesis was present in 19 patients, or 45% of the affected arms, and it could involve any muscle innervated from C5 to T1. Needle EMG fails to estimate or overestimates clinical recovery in proximal muscles in this age group.
  The Journal Of Hand Surgery 10/2007; 32(7):999-1004. · 1.35 Impact Factor
• Article: Cervical rib fracture: an unusual etiology of thoracic outlet syndrome in a child.

  Roberto S Martins, Mario G Siqueira
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  ABSTRACT: Thoracic outlet syndrome in children is an extremely rare disorder. Only 5 previous reports were presented in the literature with a description of thoracic outlet syndrome in 8 children. In these cases, the diagnosis of a cervical rib was common. We describe a case of neurogenic thoracic outlet syndrome in a 9-year-old patient where the initial symptoms occurred 2 months after a fall. Clinically, the patient developed progressive pain, numbness and tingling along the inner surface of the left forearm and in the palmar surface of the fourth finger and lateral aspect of the fifth finger. A plain radiography showed a cervical rib fracture and an electrophysiologic study suggested the presence of left lower brachial plexus neuropathy. Her fractured cervical rib was resected through a supraclavicular approach. Her symptoms resolved completely in the postoperative period. Although very rare one should keep in mind the possibility of thoracic outlet syndrome in children, especially with a history of trauma over the shoulder girdle presenting with a cervical rib and a lower brachial plexopathy.
  Pediatric Neurosurgery 02/2007; 43(4):293-6. · 0.70 Impact Factor
• Article: Wrist immobilization after carpal tunnel release: a prospective study.

  Roberto S Martins, Mario G Siqueira, Hougelli Simplício
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  ABSTRACT: This prospective study evaluates the possible advantages of wrist immobilization after open carpal tunnel release comparing the results of two weeks immobilization and no immobilization. Fifty two patients with idiopathic carpal tunnel syndrome were randomly selected in two groups after open carpal tunnel release. In one group (A, n=26) the patients wore a neutral-position wrist splint continuously for two weeks. In the other group (B, n=26) no wrist immobilization was used. Clinical assessment was done pre-operatively and at 2 weeks follow-up and included the two-point discrimination test at the second finger and two questionnaires as an outcome measurement of symptoms severity and intensity. All the patients presented improvement in the postoperative evaluations in the three analyzed parameters. There was no significant difference between the two groups for any of the outcome measurements at the final follow-up. We conclude that wrist immobilization in the immediate post-operative period have no advantages when compared with no immobilization in the end result of carpal tunnel release.
  Arquivos de Neuro-Psiquiatria 10/2006; 64(3A):596-9. · 0.72 Impact Factor
• Article: Diagnosis and Management of Peripheral Nerve Schwannomas

  Mario G. Siqueira, Roberto S. Martins
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  ABSTRACT: An abstract is unavailable. This article is available as HTML full text and PDF.
  Contemporary Neurosurgery. 08/2006; 28(16):1–5.
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  Available from: sbn.com.br

  Article: The controversial arcade of Struthers.

  Mario G Siqueira, Roberto S Martins
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  ABSTRACT: The occurrence, incidence, and relevance of the arcade of Struthers as a point of compression of the ulnar nerve at the elbow region are still controversial. This study was conducted to determine the incidence of the arcade of Struthers on anatomical dissections and to analyze the data from the literature concerning this anatomical structure. The medial surface of the distal third of the arm was dissected in 60 limbs of frozen nonfixed cadavers, and the region was surveyed for the existence of musculotendinous and fibrous structures resembling an arch. When present, its appearance, extension, distance from the medial humeral epicondyle, and relation with the ulnar nerve were recorded. A musculotendinous arcade, defined as arcade of Struthers, was identified in 8 limbs (13.5%). The extension of the arcade ranged from 2.5 to 5.0 cm (median 3.75 cm), and the distance between its distal limit and the medial humeral epicondyle ranged from 3 to 10 cm (median 6.82 cm). No evidence of ulnar nerve compression was found in the specimens where an arcade was identified. Although the use of the term arcade of Struthers seems to be historically incorrect, this relatively rare anatomical structure does exist. Well recognized as a potential secondary site of compression of the ulnar nerve at the elbow in patients submitted to anterior transposition surgery, its importance as a primary site of compression probably has been underestimated.
  Surgical Neurology 02/2005; 64 Suppl 1:S1:17-20; discussion S1:20-1. · 1.67 Impact Factor
• Article: Overall assessment of regeneration in peripheral nerve lesion repair using fibrin glue, suture, or a combination of the 2 techniques in a rat model. Which is the ideal choice?

  Roberto S Martins, Mario G Siqueira, Ciro F Da Silva, José P P Plese
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  ABSTRACT: Nerve repair with fibrin glue is an alternative to conventional suture technique, although there is no definitive experimental evaluation of the 2 techniques. This experimental study was undertaken to evaluate nerve regeneration after sciatic nerve repair with fibrin glue and to compare it with repair performed with suture and a combination of both techniques. Eighty-six male Wistar rats were subjected to right sciatic nerve transection and immediate repair with 4-stitch nylon suture (group A), fibrin glue (group B), or a combination of both techniques (group C). Walking track analysis to access functional recovery was performed preoperatively and 12 weeks postoperatively. Before nerve section and after a 24-week interval, the nerve and motor action potentials (MAPs) were evaluated. Histomorphometric evaluation was carried out 24 weeks after nerve section. Differences between groups were evaluated for significance using the Kruskal-Wallis or analysis of variance methods. Animals of group B presented better results than those of group A when the functional evaluation was applied (P < .05). When nerve conduction velocity was evaluated at reoperation and the ratio between conduction velocity at reoperation and before the nerve section in MAP evaluation were measured and compared in the 3 groups, the rats of group B presented better results than those of group A (P < .05). Animals of group C presented better results than those of group A when the ratio between nerve conduction velocities was considered. There was no difference between the nerve repair methods when histomorphometric evaluation was performed. In a rat model, nerve repair using fibrin glue provided better conditions for regeneration than suture after sciatic nerve transection.
  Surgical Neurology 02/2005; 64 Suppl 1:S1:10-6; discussion S1:16. · 1.67 Impact Factor
• Article: [Symptomatic neuroma of the sural nerve a rare complication of the harvesting of the nerve for grafting: case report].

  Roberto S Martins, Mario G Siqueira, Antonio João Tedesco-Marchese
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  ABSTRACT: The harvesting of the sural nerve for autologous grafting usually produces symptoms of low intensity and short duration. In rare occasions that procedure may lead to the formation of a symptomatic neuroma in the proximal stump. The symptoms of this complication are usually controlled by clinical treatment and the surgical procedure is left for the therapeutic failures. In this paper we present the case of a patient with a sural nerve neuroma submitted to surgical treatment by a variant of the centro-central anastomosis technique, developed for the treatment of amputation neuromas, that resulted in remission of the painful symptomatology. The different options of surgical treatment for this rare entity are discussed.
  Arquivos de Neuro-Psiquiatria 10/2002; 60(3-B):866-8. · 0.72 Impact Factor