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Dive into the research topics where Radek Kaiser is active.

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Featured researches published by Radek Kaiser.


Acta Neurochirurgica | 2012

Types and severity of operated supraclavicular brachial plexus injuries caused by traffic accidents

Radek Kaiser; Petr Waldauf; Pavel Haninec

BackgroundBrachial plexus injuries occur in up to 5% of polytrauma cases involving motorcycle accidents and in approximately 4% of severe winter sports injuries. One of the criteria for a successful operative therapy is the type of lesion. Upper plexus palsy has the best prognosis, whereas lower plexus palsy is surgically untreatable. The aim of this study was to evaluate a group of patients with brachial plexus injury caused by traffic accidents, categorize the injuries according to type of accident, and look for correlations between type of palsy (injury) and specific accidents.MethodsA total of 441 brachial plexus reconstruction patients from our department were evaluated retrospectively (1993 to 2011). Sex, age, neurological status, and the type and cause of injury were recorded for each case. Patients with BPI caused by a traffic accident were assessed in detail.ResultsTraffic accidents were the cause of brachial plexus injury in most cases (80.7%). The most common type of injury was avulsion of upper root(s) (45.7%) followed by rupture (28.2%), complete avulsion (16.9%) and avulsion of lower root(s) (9.2%). Of the patients, 73.9% had an upper, 22.7% had a complete and only 3.4% had a lower brachial plexus palsy. The main cause was motorcycle accidents (63.2%) followed by car accidents (23.5%), bicycle accidents (10.7%) and pedestrian collisions (3.1%) (p < 0.001). Patients involved in car accidents had a higher percentage of lower avulsion (22.7%) and a lower percentage of upper avulsion (29.3%), whereas cyclists had a higher percentage of upper avulsion (68.6%) based on the data from the entire group of patients (p < 0.001). Lower plexus palsy was significantly increased in patients after car accidents (9.3%, p < 0.05). In the two main groups (car and motorcycle accidents), significantly more upper and fewer lower palsies were present. In the bicycle accident group, upper palsy was the most common (89%).ConclusionStudy results indicate that the most common injury was an upper plexus palsy. It was characteristic of bicycle accidents, and significantly more common in car and motorcycle accidents. The results also indicate that it is important to consider the potential of a brachial plexus injury after serious traffic accidents and to examine both upper extremities in detail even if some motor function is preserved.


BMC Neuroscience | 2012

Enhancement of musculocutaneous nerve reinnervation after vascular endothelial growth factor (VEGF) gene therapy

Pavel Haninec; Radek Kaiser; Vladimir Bobek; Petr Dubový

BackgroundVascular endothelial growth factor (VEGF) is not only a potent angiogenic factor but it also promotes axonal outgrowth and proliferation of Schwann cells. The aim of the present study was to quantitatively assess reinnervation of musculocutaneous nerve (MCN) stumps using motor and primary sensory neurons after plasmid phVEGF transfection and end-to-end (ETE) or end-to-side (ETS) neurorrhaphy. The distal stump of rat transected MCN, was transfected with plasmid phVEGF, plasmid alone or treated with vehiculum and reinnervated following ETE or ETS neurorrhaphy for 2 months. The number of motor and dorsal root ganglia neurons reinnervating the MCN stump was estimated following their retrograde labeling with Fluoro-Ruby and Fluoro-Emerald. Reinnervation of the MCN stumps was assessed based on density, diameter and myelin sheath thickness of regenerated axons, grooming test and the wet weight index of the biceps brachii muscles.ResultsImmunohistochemical detection under the same conditions revealed increased VEGF in the Schwann cells of the MCN stumps transfected with the plasmid phVEGF, as opposed to control stumps transfected with only the plasmid or treated with vehiculum. The MCN stumps transfected with the plasmid phVEGF were reinnervated by moderately higher numbers of motor and sensory neurons after ETE neurorrhaphy compared with control stumps. However, morphometric quality of myelinated axons, grooming test and the wet weight index were significantly better in the MCN plasmid phVEGF transfected stumps. The ETS neurorrhaphy of the MCN plasmid phVEGF transfected stumps in comparison with control stumps resulted in significant elevation of motor and sensory neurons that reinnervated the MCN. Especially noteworthy was the increased numbers of neurons that sent out collateral sprouts into the MCN stumps. Similarly to ETE neurorrhaphy, phVEGF transfection resulted in significantly higher morphometric quality of myelinated axons, behavioral test and the wet weight index of the biceps brachii muscles.ConclusionOur results showed that plasmid phVEGF transfection of MCN stumps could induce an increase in VEGF protein in Schwann cells, which resulted in higher quality axon reinnervation after both ETE and ETS neurorrhaphy. This was also associated with a better wet weight biceps brachii muscle index and functional tests than in control rats.


Injury-international Journal of The Care of The Injured | 2014

Injuries associated with serious brachial plexus involvement in polytrauma among patients requiring surgical repair

Radek Kaiser; Libor Mencl; Pavel Haninec

BACKGROUND Brachial plexus injury occurs in up to 5% of polytrauma cases involving motorcycle crashes and in approximately 4% of severe winter sports injuries. One of the conditions for the success of operative therapy is early detection, ideally within three months of injury. The aim of this study was to evaluate associated injuries in patients with severe brachial plexus injury and determine whether there is a characteristic concomitant injury (or injuries), the presence of which, in the polytrauma, could act as a marker for nerve structures involvement and whether there are differences in severity of polytrauma accompanying specific types of brachial plexus injury. METHODS We evaluated retrospectively 84 surgical patients from our department, from 2008 to 2011, that had undergone brachial plexus reconstruction. For all, an injury severity scale (ISS) score and all major associated injuries were determined. RESULTS 72% of patients had an upper, 26% had a complete and only 2% had a lower brachial plexus palsy. The main cause was motorcycle crashes (60%) followed by car crashes (15%). The average ISS was 35.2 (SD=23.3), although, values were significantly higher in cases involving a coma (59.3, SD=11.0). The lower and complete plexus injuries were significantly associated with coma and fractures of the shoulder girdle and injuries of lower limbs, thoracic organs and head. Upper plexus injuries were associated with somewhat less severe injuries of the upper and lower extremities and less severe injuries of the spine. CONCLUSION Serious brachial plexus injury is usually accompanied by other severe injuries. It occurs in high-energy trauma and it can be stated that patients involved in motorcycle and car crashes with multiple fractures of the shoulder girdle are at high risk of nerve trauma. This is especially true for patients in a primary coma. Lower and complete brachial plexus injuries are associated with higher injury severity scale.


Journal of Neurosurgery | 2013

End-to-side neurorrhaphy in brachial plexus reconstruction

Pavel Haninec; Libor Mencl; Radek Kaiser

OBJECT Although a number of theoretical and experimental studies dealing with end-to-side neurorrhaphy (ETSN) have been published to date, there is still a considerable lack of clinical trials investigating this technique. Here, the authors describe their experience with ETSN in axillary and musculocutaneous nerve reconstruction in patients with brachial plexus palsy. METHODS From 1999 to 2007, out of 791 reconstructed nerves in 441 patients treated for brachial plexus injury, the authors performed 21 axillary and 2 musculocutaneous nerve sutures onto the median, ulnar, or radial nerves. This technique was only performed in patients whose donor nerves, such as the thoracodorsal and medial pectoral nerves, which the authors generally use for repair of axillary and musculocutaneous nerves, respectively, were not available. In all patients, a perineurial suture was carried out after the creation of a perineurial window. RESULTS The overall success rate of the ETSN was 43.5%. Reinnervation of the deltoid muscle with axillary nerve suture was successful in 47.6% of the patients, but reinnervation of the biceps muscle was unsuccessful in the 2 patients undergoing musculocutaneous nerve repair. CONCLUSIONS The authors conclude that ETSN should be performed in axillary nerve reconstruction but only when commonly used donor nerves are not available.


Journal of Neurosurgery | 2012

Axillary nerve repair by fascicle transfer from the ulnar or median nerve in upper brachial plexus palsy

Pavel Haninec; Radek Kaiser

OBJECT Nerve repair using motor fascicles of a different nerve was first described for the repair of elbow flexion (Oberlin technique). In this paper, the authors describe their experience with a similar method for axillary nerve reconstruction in cases of upper brachial plexus palsy. METHODS Of 791 nerve reconstructions performed by the senior author (P.H.) between 1993 and 2011 in 441 patients with brachial plexus injury, 14 involved axillary nerve repair by fascicle transfer from the ulnar or median nerve. All 14 of these procedures were performed between 2007 and 2010. This technique was used only when there was a deficit of the thoracodorsal or long thoracic nerve, which are normally used as donors. RESULTS Nine patients were followed up for 24 months or longer. Good recovery of deltoid muscle strength was seen in 7 (77.8%) of these 9 patients, and in 4 patients with less follow-up (14-23 months), for an overall success rate of 78.6%. The procedure was unsuccessful in 2 of the 9 patients with at least 24 months of follow-up. The first showed no signs of reinnervation of the axillary nerve by either clinical or electromyographic evaluation in 26 months of follow-up, and the second had Medical Research Council (MRC) Grade 2 strength in the deltoid muscle 36 months after the operation. The last of the group of 14 patients has had 12 months of follow-up and is showing progressive improvement of deltoid muscle function (MRC Grade 2). CONCLUSIONS The authors conclude that fascicle transfer from the ulnar or median nerve onto the axillary nerve is a safe and effective method for reconstruction of the axillary nerve in patients with upper brachial plexus injury.


BMC Neurology | 2014

Usefulness of screening tools in the evaluation of long-term effectiveness of DREZ lesioning in the treatment of neuropathic pain after brachial plexus injury

Pavel Haninec; Radek Kaiser; Libor Mencl; Petr Waldauf

BackgroundDespite high success rate of DREZ lesioning in the treatment of intractable central pain, there is still a significant incidence of patients without satisfactory post-operative effect. The aim of the study was to evaluate the long-term effect of DREZ lesioning using both a subjective assessment using a visual analog scale (VAS) to quantify residual pain and an assessment using the screening tool (painDETECT Questionnaire, PD-Q).MethodsDREZ lesioning was performed in 52 patients from a total 441 cases with brachial plexus injury (11.8%) during a 17-year period (1995–2011). The effect of surgery was retrospectively assessed in 48 patients.ResultsA decrease in pre-operative pain by more than 75% (Group I) was achieved in 70.8% of patients and another 20.8% reported significant improvement (Group II). The surgery was unsucessful in 8.4% (Group III). We found a significant correlation between ‘improvement’ groups from both methods of assessments. Patients from Group I usually complained of residual nociceptive pain according to PD-Q, patients from Group II typically had pain of unclear origin, and all cases those in Group III suffered from neuropathic pain, Cramer’s V = .66, P < .001. Overall, 66.7% of patients had resolved neuropathic pain, 20.8% patients had more serious complaints and may also suffer from residual neuropathic pain, while 12.5% had unresolved neuropathic pain.ConclusionDREZ lesioning is a safe and effective method with success rates of about 90%. PD-Q scores correspond to subjective satisfaction with the surgery and it seems to be a suitable screening tool for finding patients with residual neuropathic pain after surgery.


Plastic and Reconstructive Surgery | 2012

The end-to-side neurorrhaphy in axillary nerve reconstruction in patients with brachial plexus palsy.

Pavel Haninec; Radek Kaiser

1. Kocak E, Al-Saif O, Satter M, et al. Image guidance during abdominal exploration for recurrent colorectal cancer. Ann Surg Oncol. 2007;14:405–410. 2. Rozen WM, Ashton MW, Stella DL, Phillips TJ, Taylor GI. Stereotactic image-guided navigation in the preoperative imaging of perforators for DIEP flap breast reconstruction. Microsurgery 2008;28:417–423. 3. Rozen WM, Ashton MW, Stella DL, et al. Developments in perforator imaging for the anterolateral thigh flap: CT angiography and CT-guided stereotaxy. Microsurgery 2008;28:227–232. 4. Rozen WM, Buckland A, Ashton MW, Stella DL, Phillips TJ, Taylor GI. Image-guided, stereotactic perforator flap surgery: A prospective comparison of current techniques and review of the literature. Surg Radiol Anat. 2009;31:401–408.


Plastic Surgery Case Studies | 2016

Acutely Reconstructed Isolated Supraclavicular Brachial Plexus Injury Caused By a Chainsaw

Radek Kaiser; Gautham Ullas

Lacerations to the brachial plexus are rare. The author describes a case involving a man who sustained a chainsaw wound to the neck with isolated injury to the proximal part of the upper trunk of the brachial plexus. The patient underwent acute surgical exploration. After resection of the lacerated ends of the nerve stumps, four nerve grafts from the sural nerve were used for the reconstruction. Reinnervation was successful and the patient was able to abduct his arm (Medical Research Council 5 of 5) and flex his elbow (Medical Research Council 4 of 5) to its full range, within 24 months.


Journal of Spinal Disorders & Techniques | 2015

Can MRI Predict Flexibility in Scheuermann Kyphosis Patients

Radek Kaiser; Eyal Behrbalk; Michael Walsh; Petr Waldauf; Ana Belen Perez Romera; Hossein Mehdian

Study Design: Retrospective, blinded analysis of imaging studies. Objective: The aim of this study is compare the use of magnetic resonance imaging (MRI) to lateral radiograph using bolster in the evaluation of Scheuermann kyphosis (SK) curve flexibility measurement. Summary and Background Data: The flexibility of the thoracic curve [thoracic kyphosis (TK)] in SK is of primary importance in its preoperative planning. Several methods have been described for SK curve flexibility measurement. The most commonly used method is lateral hyperextension radiography on hard bolster [hyperextension radiograph (HE)]. No current methods use MRI for flexibility assessment. Materials and Methods: Flexibility of TK in SK patients was measured as a difference between standing radiograph and bolster-assisted lateral HE or supine MRI. The sagittal Cobb angle of the TK was measured between the superior endplate of T4 and the inferior endplate of T12 vertebral body. Flexibilities measured by these 2 methods were compared and analyzed using the generalized estimating equation analysis and the correlation analysis. Results: We assessed 18 SK patients (14 males and 4 females) with mean age of 20.06±6.03 years. The standing TK x-rays showed 83.8±6.1 degrees. On HE, TK curve reduced by 39.3 degrees (95% confidence interval, 35.8–42.9) to 44.5±6.2 degrees (P<0.001). Preoperative MRI images showed TK of 53.8±5.9 degrees which means reduction by 30 degrees (95% confidence interval, 26.6–33.4) from the standing radiographs (P<0.001). Linear dependency between HE and MRI flexibility with a mean difference of 9.3 degrees was found (R2=0.61, P<0.001). Conclusions: Our study shows that preoperative MRI can be used for SK flexibility assessment with similar predictive value as routinely used bolster-assisted hyperextension lateral radiograph. Consequently, patient exposure to preoperative hyperextension ionizing radiation may be reduced.


Neurosurgical Review | 2018

Epidemiology, etiology, and types of severe adult brachial plexus injuries requiring surgical repair: systematic review and meta-analysis

Radek Kaiser; Petr Waldauf; Gautham Ullas; Aneta Krajcová

The literature describing epidemiology, etiology, and types of serious brachial plexus injuries (BPIs) is sparse. The aim of this review was to investigate the epidemiological and etiopathogenetical data of serious BPIs undergoing surgical reconstruction. A systematic search was conducted from January 1985 to December 2017. All studies that reported data about prevalence of specific types and causes of BPIs in adults treated surgically were included and cumulatively analyzed. Ten studies including 3032 patients were identified. The pooled prevalence of closed BPIs was 93% (95% CI: 87–97%), lacerations accounted for 3% (95% CI: 1–6%), and gunshot wounds (GSWs) for 3% (95% CI: 0–7%). The prevalence of male patients was 93% (95% CI: 90–96%) and female cases 7% (95% CI: 4–10%). The most common cause of closed BPI was motorcycle accidents with 67% (95% CI: 49–82%) prevalence followed by car crashes with 14% (95% CI: 8–20%). Other causes were rare. Ninety percent (95% CI: 78–98%) of patients suffered from a supraclavicular or combined supra-/infraclavicular trauma, while 10% (95% CI: 2–22%) from isolated infraclavicular injury. The prevalence of complete lesions was 53% (95% CI: 47–58%) followed by upper plexus lesion with 39% (95% CI: 31–48%) and lower plexus injury with 6% (95% CI: 1–12%). This meta-analysis demonstrates that the typical patient suffering from severe BPI is a male after motorcycle accident with closed supraclavicular injury causing complete or slightly less commonly upper plexus palsy. Lacerations and GSWs of brachial plexus are rare.

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Pavel Haninec

Charles University in Prague

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Petr Waldauf

Charles University in Prague

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Libor Mencl

Charles University in Prague

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Vladimir Bobek

Charles University in Prague

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Aneta Krajcová

Charles University in Prague

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Ana Belen Perez Romera

Nottingham University Hospitals NHS Trust

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Belen Perez

University of Nottingham

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