Occipital artery to vertebral artery bypass for treatment of bilateral vertebral artery occlusion with QMRA as an adjunct to diagnostic assessment

PURPOSE

Stroke, the second leading cause of death globally, often involves ischemia in the vertebrobasilar territory. This condition is underexplored, despite significant morbidity and mortality risks. The purpose of this study is to present a case of occipital artery to V3 segment vertebral artery bypass, emphasizing the role of quantitative magnetic resonance angiography (qMRA) in assessing flow and guiding surgical intervention.

METHODS

A 66-year-old man with bilateral vertebral artery occlusion presented acute symptoms. qMRA was employed to evaluate flow dynamics and determine the feasibility of a flow augmentation bypass surgery. The occipital artery to left vertebral artery bypass (OA-to-VA) was performed, utilizing an inverted hockey-stick incision and an antegrade inside-out technique. The patency of the bypass was confirmed using both Doppler probe and Indocyanine green.

RESULTS

Postoperative assessments, including computed tomography angiography (CTA) and qMRA, demonstrated the patency of the bypass with improved flow in the basilar artery and left vertebral artery. The patient's condition remained stable postoperatively, with residual peripheral palsy of the left facial nerve.

CONCLUSION

In conclusion, the presented case illustrates the efficacy of the OA-to-VA bypass in addressing symptomatic bilateral vertebral artery occlusion. The study underscores the pivotal role of qMRA in pre- and postoperative assessments, providing noninvasive flow quantification for diagnostic considerations and long-term follow-up in patients with vertebrobasilar insufficiency.

Removal of grade IV vestibular schwannomas by retrosigmoid approach: results of a cumulative series of two European centers

INTRODUCTION

The aim of our study was to study the association between end-of-surgery facial nerve stimulation threshold and extent of tumor resection in case of grade IV vestibular schwannomas.

MATERIALS AND METHODS

Grade IV VSs represent a surgical challenge as a risk/benefit ratio must be considered in balancing a satisfactory extent of resection against a good postoperative functional outcome. We reviewed a cumulative series of 57 patients with large/giant VSs who were operated on by retrosigmoid approach in the period from 2008 to 2018 in two European centers, namely San Filippo Neri Hospital, Rome, Italy and Masaryk Hospital, Usti nad Labem, Czech Republic. Extent of resection, intraoperative direct electrical stimulation threshold of facial nerve and postoperative facial outcome were examined.

RESULTS

Total or near-total resection was accomplished in 40 (75.5%) cases. Two groups were compared: total or near-total resection (T + NT) and subtotal resection (ST); the end-of-surgery facial nerve stimulation threshold significantly differed (T + NT: 0.24 mA, ST: 0.44 mA, p = 0.036). A critical cutoff was found at 0.2mA; values similar or inferior to this correctly predicted total or near-total resection in 86.7% of cases. Thirty (56.6%) patients had a normal postoperative facial outcome (HB1). Among the 40 patients in T + NT group, 32 (80%) retained an acceptable facial function (HB1-2).

CONCLUSIONS

Lower facial nerve stimulation thresholds positively predict a broader extent of resection and total or -near total resection should be accomplished in such cases. Judicious (subtotal) resection is preferred if threshold values increase while dissecting firmly adherent tumors.

Next generation sequencing of glioblastoma circulating tumor cells: non-invasive solution for disease monitoring

Treatment of aggressive glioblastoma multiforme (GBM) must be based on very precise histological and molecular diagnostic of GBM type. According to the WHO guidelines, only tissue biopsy is a relevant source of cellular material evaluated in the diagnostic process to specify the tumor features. Nevertheless, obtaining a GBM biopsy is complicated and relies mostly on resection surgery. Evaluating circulating free DNA and/or circulating tumor cells (CTCs) in the clinic, using a liquid biopsy could represent a non-invasive cancer care optimization. In the present study, the peripheral blood of patients undergoing GBM resection (n = 18) was collected and examined for CTCs. The feasibility of GBM molecular diagnostics from a simple non-invasive peripheral blood withdrawal was evaluated. The size-based enriched CTCs were analyzed using cytomorphology and their origin confirmed based on mutational analysis. In addition, shared DNA mutations in CTCs and in primary tumor tissue were searched. For the identification of CTCs, next generation sequencing (NGS) was used. The GeneReader™ sequencing platform enables targeted sequencing of a 12-gene panel and direct evaluation of detected gene variations using QIAGEN Clinical Insight Analyze (QCI-A) software with a special algorithm for liquid biopsy sequencing analysis. Herein, we present a standard operating procedure for CTC enrichment in GBM patients, CTC in vitro culture, CTC cytomorphological evaluation, and NGS analysis of CTCs using the QIAGEN Actionable Insights Tumor (ATP) Panel. CTCs were present in all tested patients (18/18). The NGS data generated for formalin-fixed paraffin-embedded (FFPE) primary tumor tissues and CTCs reached significantly high-quality parameters. The comparisons between different sample types (CTCs vs. primary tumors) and sampling area (different primary tumor regions) showed a significant level of concordance, indicating CTC testing could be used for patient monitoring and recurrence awareness. Notably, more mutations were detected when analyzing CTC samples compared with the paired primary tumors (n = 3). The results confirm the feasibility of using CTCs as a source of tumor DNA in a diagnostic process, especially when evaluating the molecular characteristics of GBMs. A major advantage of the presented NGS approach for detecting CTCs is the simultaneous identification of several markers relevant for GBM diagnostics, allowing molecular diagnostics on cytological specimens and potential administration of innovative targeted therapies.

Magnetic resonance markers of bilateral neuronal metabolic dysfunction in patients with unilateral internal carotid artery occlusion

OBJECTIVES

To evaluate cerebral hemodynamic, metabolic and anatomic changes occurring in patients with unilateral occlusion of the internal carotid artery (ICA).

MATERIALS AND METHODS

Twenty-two patients with unilateral occlusion of ICA and twenty age and sex matched healthy subjects were included in the study. Single voxel proton magnetic resonance spectroscopy (¹H-MRS) of the centrum semiovale, semi-automated hippocampal volumetry in T1-weighted scans and transcranial Doppler examination (TCD) with calculation of Breath Holding Index (BHI) were performed in both groups. Metabolic, anatomic, and hemodynamic features were compared between the two groups.

RESULTS

The N-acetylaspartate (NAA)/choline (Cho) ratio was significantly lower in both hemispheres of enrolled patients compared to controls (p = 0.005 for the side with occlusion, p = 0.04 for the side without occlusion). The hippocampus volume was significantly reduced bilaterally in patients compared to healthy subjects (p = 0.049). A statistically significant difference in BHI values was observed between the side with occlusion and without occlusion (p = 0.037) of the patients, as well as between BHI values of the side with occlusion and healthy volunteers (p = 0.014).

DISCUSSION

Patients with unilateral ICA occlusion have reduced NAA/Cho ratio in the white matter of both hemispheres and have bilateral atrophy of hippocampus. The alteration of hemodynamics alone cannot explain these changes.

Ventriculoperitoneal Shunt Complications in the European Idiopathic Normal Pressure Hydrocephalus Multicenter Study

BACKGROUND

Ventriculoperitoneal shunt (VP-shunt) is the standard of treatment for idiopathic normal pressure hydrocephalus (iNPH). However, a thorough investigation of VP-shunt complications in this population is lacking.

OBJECTIVE

To present the analysis and the rates of complications progressively occurring during the first year after shunt surgery in the patients with iNPH included in the European multicenter (EU-iNPH) study.

METHODS

Patients (n = 142) were prospectively included in the EU-iNPH study by 13 institutions. All patients received a programmable VP-shunt. One hundred fifteen patients completed the 12-mo follow-up. Reexaminations were performed 1, 3, and 12 mo after surgery. Data regarding symptomatic over- or underdrainage, infections, malposition, subdural collections, and shunt surgery were collected and analyzed.

RESULTS

Thirty patients (26%) experienced symptoms due to shunt underdrainage. Symptomatic overdrainage was reported in 10 (9%). Shunt adjustments were made in 43 (37%). Shunt malposition was recognized as the primary cause of shunt malfunction in 8 (7%), while only 1 infection (0.9%) occurred. Subdural hematoma was diagnosed in 7 (6%) and was treated by increasing the opening pressure of the valve in 5 patients. Hygroma was diagnosed in 10 (9%), requiring surgery in 1 patient. Overall, 17 patients (15%) underwent 19 shunt surgeries.

CONCLUSION

The advances in valve technology, a careful opening pressure setting, and rigorous follow-up allow a significant reduction of complications, which can be usually managed nonsurgically within the first 3 to 6 mo.

Ethical triage during the COVID-19 pandemic: a toolkit for neurosurgical resource allocation

BACKGROUND

The COVID-19 pandemic confronts healthcare workers, including neurosurgeons, with difficult choices regarding which patients to treat.

METHODS

In order to assist ethical triage, this article gives an overview of the main considerations and ethical principles relevant when allocating resources in times of scarcity.

RESULTS

We discuss a framework employing four principles: prioritizing the worst off, maximizing benefits, treating patients equally, and promoting instrumental value. We furthermore discuss the role of age and comorbidity in triage and highlight some principles that may seem intuitive but should not form a basis for triage.

CONCLUSIONS

This overview is presented on behalf of the European Association of Neurosurgical Societies and can be used as a toolkit for neurosurgeons faced with ethical dilemmas when triaging patients in times of scarcity.

Correction to: Editorial re: Facial nerve function and hearing after microsurgical removal of sporadic vestibular schwannomas in a population-based cohort by Ismail Taha et al

Incorrect name of author, the correct name shoud be Martin Sames.

Masseteric nerve supercharge bypass in primary reconstruction of facial nerve

Facial paralysis is a severe disease and presents a formidable treatment challenge. A wide variety of surgical procedures are available with limited evidence. Major risk factors of suboptimal recovery include the duration of paralysis as well as higher age. In this paper, we demonstrate reconstruction of the facial nerve via an intratemporal end-to-end anastomosis and concomitant transfer of an intact masseteric nerve to the side of facial nerve trunk. The supercharge (reverse end-to-side) transfer resulted in preservation of target muscles and faster recovery. Masseteric supercharge bypass may be an acceptable surgical technique to restore muscle function in potentially higher risk cases.

Distant white-matter diffusion changes caused by tumor growth

OBJECTIVES

Various reports have suggested that the involvement of normal-looking white matter with tumors is not limited to just signal abnormalities detectable on conventional imaging. Thus, the purpose of this study was to investigate the distant effects of glioblastomas and metastases on white matter using diffusion tensor imaging (DTI).

MATERIALS AND METHODS

Data for 21 patients harboring a glioblastoma (n=12) or a metastasis (n=9) located at a distance of smaller or equal to 10mm from a DTI-based reconstruction of the pyramidal tract were analyzed, using regions of interest (ROIs) placed along the pyramidal tracts in the cerebral peduncle distant (>15 mm) from the tumor.

RESULTS

For the whole study population, fractional anisotropy (FA) was significantly lower on the side ipsilateral to the tumor (P<0.001), a difference that was also observed in the glioblastoma and metastasis subgroups. The trace value was significantly higher on the ipsilateral side in the whole population and metastasis subgroup, but not in the glioblastoma subgroup. The decrease in FA and the trace value increase were significant in a subgroup of patients with motor deficits, but not in those without such deficits.

CONCLUSION

Hemispheric glioblastomas and metastases located close to the pyramidal tract induce diffusion changes in the tract that are observable at a distance of greater than 15 mm from the tumor border in the absence of T2 signal changes. These changes are different in glioblastomas and metastases, and mechanisms other than Wallerian degeneration may be contributing to the observed changes.

Decompressive surgery for malignant supratentorial infarction remains underutilized after guideline publication

Decompressive surgery <48 h from stroke onset reduces the prevalence of mortality and morbidity from malignant supratentorial infarction. We investigated if utilization of decompressive surgery changed in the Czech Republic (CZ) after the release of new guidelines regarding treatment of malignant brain infarction. The volume of decompressive surgery in 2009 in all centers in the CZ was assessed using the same methodology as in 2006. All neurosurgery departments in the CZ were asked to complete a questionnaire and asked to identify all cases of decompressive surgery for malignant brain infarction through a combination of discharge codes for "brain infarction" and "decompressive surgery" from electronic hospital charts. Data for 56 patients were obtained from 15 of the 16 neurosurgery departments in the CZ. The average age was 53 ± 13; number of males 20; median time to surgery was 48 h (range 24-62); median NIHSS score was 25 (IQR, 20-30); median infarct volume was 300 cm(3) [interquartile (IQR, 250-350)]; mean shift on CT was 10.6 ± 3.6 mm and size of hemicraniectomy was 125 cm(2) (IQR, 110-154). A favorable outcome was achieved in 45% of the patients. The number of procedures increased from 39 in 2,006 to 2,056 in 2009. Based on data from one stroke center, 10% suffered from malignant supratentorial infarction and 2.3% met the criteria for decompressive surgery. In 2009, as compared to 2006, the volume of decompressive surgery carried out moderately increased. However, procedures remained underutilized because only ~10% of those who needed decompressive surgery underwent surgery.

An anatomical and radiological study of the high jugular bulb on high-resolution CT scans and alcohol-fixed skulls of adults

Although many reports mention a "high jugular bulb" (HJB), it is often not clearly defined. We examined the relationship between the jugular bulb (JB) and the internal auditory canal (IAC) in 200 temporal bones on high resolution CT scans and alcohol-fixed skull bases of adults. The average distance (+/-standard deviation) between the IAC and the JB was 7.5+/-2.3mm (range, 1-16 mm). The JB was higher on the right side than its companion in 53.3% of patients (left side only in 22%; no side dominance in 23.7% of bases). When the JB reached or exceeded the floor of the IAC (16.5%), it was defined as a HJB; 61% of HJB were found in females. Bilateral HJB was found in 0.5% of patients. The HJB was not associated with a contralateral flat JB. Preoperative multiplanar high resolution CT reconstructions make the most detailed assessment of structural topography.

Abducens nerve schwannoma mimicking intrinsic brainstem tumor

Schwannomas of the abducens nerve are extremely rare tumors affecting cavernous, cisternal or both segments of sixth cranial nerve. Clinical features and neuroradiological imagery are frequently insufficient to reach an accurate pre-operative diagnosis. We report a patient with a cystic tumor with ring-like contrast enhancement at the right anterior pontomesencephalic junction. Radical excision was performed via anterior transpetrosal approach and showed an extrinsic tumor originating from the sixth nerve. A postoperative sixth nerve palsy had disappeared completely 9 months after the surgery. The correct diagnosis of an abducens nerve schwannoma is established by the intraoperative finding of a tumor attachment to the sixth nerve and by histopathological analysis. The various differential diagnoses, the clinical and radiological features of this diagnosis and management are issues discussed in this illustrated review.

[Results of the treatment of odontoid fractures by osteosynthesis with a single axial screw]

PURPOSE OF THE STUDY

The authors present the clinical results of odontoid fracture treatment, using a single axial screw, with the aim to compare their results with the findings of other relevant studies, with focus on the use of either one or two axial screws.

MATERIAL

Thirty patients were included in the study, 16 men and 14 women at an average age of 56.1 years. They had findings of type II and "shallow" type III fractures, as evaluated on the basis of Anderson and D'Alonzo classification, and combined fractures. All were managed by the method of direct osteosynthesis of the dens with a single axial screw from the anterior approach in the years 1998 to 2005.

METHODS

The retrospective, cross-study analysis was based on records and clinical notes from the outpatient department and on radiographic materials from the department of radiology at follow-ups of 3, 6 and 12 months after surgery. The criteria assessed included screw insertion, quality of fusion during follow-up, and intra-operative and early and late post-operative complications.

RESULTS

Insertion of a screw was regarded as optimal in 24 (80 %) cases and suboptimal in six (20 %) cases. None of the patients required screw re-insertion. Evident fusion present at 12 months post-operatively was achieved in 18 (86 %) and questionable fusion in two patients. Non-union was recorded in one patient. Repeat operation was not indicated in any of the cases. There were no intra-operative complications. In six patients early complications occurred. Three patients died due to causes unrelated to the surgical procedure. Two patients had infectious complications not directly related to the surgery. One patient suffered from temporary dysphonia due to vocal chord edema.

DISCUSSION

For direct osteosynthesis of the dens, one or two screws can be used. Both methods have been studied in terms of biomechanics and clinical outcome, but none of the studies showed any significant differences between the two methods. Also the available Czech studies have paid only marginal attention to this issue.

CONCLUSIONS

Based on the analysis of patients' data and literature reports we can conclude that osteosynthesis employing a single axial screw gives results similar to that using two screws. The available biomechanical and clinical studies have not shown any statistically significant differences between the two methods. The results of our study are in agreement with the relevant literature data published so far. .

[Decompressive craniectomy in the treatment of posttraumatic edema and the contribution of new diagnostic methods]

The authors present a case report of a young male who suffered a brain injury complicated with malignant posttraumatic edema managed with bilateral decompressive craniectomy after conservative treatment failure. They further discuss current surgical approach to posttraumatic brain edema and contribution of new diagnostic methods in secondary brain damage management.

[The anterior approach in treatment of subaxial cervical spine injuries. (A group of 75 patients)]

AIM

The aim of the study was to evaluate long-term results of the subaxial cervical spine injuries treatment, using splint and bicortical screws stabilization via frontal access, as well as to describe the opinion on subaxial cervical spine injuries treatment methods development.

METHODOLOGY

During a twelve-year period, starting in 1990, 75 patients suffering from subaxial cervical spine injuries were treated by the authors' work-team. In 96% of the cases, decompression followed by frontal access stabilization using the Caspar technique with a splint and bicortically inserted screws was performed. The Ducker and Cooper classification scale was employed to classify the fracture type. A neurological deficit was classified according to Frankel. The trauma mechanism was determined, as well as peri- and post operation complications and the patients survival rate. Furthermore, the graphic documentation taken during the observation period was assessed.

RESULTS

In the patient group, the number of male subjects was three times higher and 56% of the patients under the age of 30 were reported. 40% of the patients were injured in conjunction with a traffic accident, 27% were injured following a fall from a height and 15% after jumping into unknown water. 30% of the patient fractures were classified as flexion-compression types, 30% as flexion-dislocation types, 32% as burst-compression types and 6% as extension fracture types. 22% of the patients were accepted as Frankel A, 7% as B, 5% as C, 14% as D and 52% were Frankel E. 91% of the patients suffered from monotrauma. 96% of the patients, using the frontal access exclusively, were treated with splints, bicortical screws and autologic grafts. The neurological picture improved in 8% of the patients, 15% died in the first year.

CONCLUSION

The surgical treatment should be aimed at the earliest possible decompression of the neurological tissue, followed by re-introduction of the stable situation. The frontal access may be, in the majority of cases, considered the access of choice.

[Results of reinnervation after peripheral nerve repair by a microsurgical technique used in 1996-1998]

PURPOSE OF THE STUDY

The authors present the results of a retrospective study of reinnervation after peripheal nerve repair by a microsurgical technique between 1996 and 1998. This is a development of a previous study by their colleagues.

MATERIAL

Between 1996 and 1998, 113 injured peripheral nerves were treated by epineuroperineural suture (Ethilon; thickness, 8/0-10/0) under a microscope. To achieve a homogeneous group, 12 median and 13 ulnar nerves were included and evaluated in this retrospective study. All nerves studied were completely severed at the distal forearm and had sharply cut ends.

METHODS

The results of reinnervation were retrospectively analyzed and classified according to the British Medical Research Council system (Seddon, 1972). The patients were followed up for 3 years. The patient's satisfaction with hand function was rated according our own classification. Tinel's sign and scar tenderness were evaluated.

RESULTS

17 patients (68%) achieved motor function M3 or higher and 16 patients (64%) had sensation S3 or higher. Better motor function was achieved after repair of the median than the ulnar nerve (M3 and higher in 91% and 46%, respectively). Better sensory recovery was achieved after repair of the ulnar than the median nerve (S3 and higher in 77% and 50%, respectively). Tinel's sign was positive in 68% of the patients; 10% of the patients complained of scar tenderness.

DISCUSSION

Our results are comparable with the studies published so far. The patients with median nerve lesions showed better improvement after repair than those with ulnar nerve lesions and the outcome was better in hands with injury to only one nerve than in those with both nerves injured. The factors that influence peripheral reinnervation and the recovery of hand function are discussed. The surgical technique used, patient's age, regenerative capacity of the peripheral nerve affected, the interval between injury and the definitive microsurgical procedure and the quality of postoperative care are considered to be most important.

CONCLUSIONS

Lesions of the peripheral nerve require special attention by a neurosurgeon competent to provide appropriate microsurgical treatment. The interval between injury and definitive treatment should be as short as possible. Postoperative care (rehabilitation and regular neurological examination) is also an important part of treatment.

[The lumbar infusion test and transcranial Doppler ultrasonography in the diagnosis and treatment of normotensive hydrocephalus. Prospective evaluation of a group of patients from 2000 to 2002]

BACKGROUND

The normal pressure hydrocephalus syndrome (NPH) is characterized by the presence of a clinical triad comprising dementia, motor apraxia, and sphincter complaint, along with the presence of distinct dilatation of the ventricular system in the absence of major cortical atrophy. The diagnosis of NPH must be confirmed by including dynamic liquor tests into the algorithm of examination. The lumbar infusion test (LIT) represents the "gold standard" of liquor dynamic tests.

METHODS AND RESULTS

The authors present 24 patients in a prospective managed study. Indication of shunt surgery was based on the result of LIT. At the time of assessment of the diagnosis 28% of the patients were greatly dependent on the nursing care; after the shunt implantation only 7% were still greatly dependent. Shunt implantation brought about increased percentage of patients who were evaluated as quite independent (rise from 14% to 64%). Control group consists of 10 patients with negative LIT results; there were no changes in evaluated parameters in this group. The coincidence of cerebrovascular diseases is probably the most common reason of nonresponsibility to shunt implantation in LIT positive patients.

Anterior approach for vertebral artery occlusion in a rabbit

BACKGROUND AND PURPOSE

Various research protocols call for the vertebral artery (VA) occlusion.

MATERIAL AND METHODS

The anterior aspect of the cervical spine was exposed, the small medial parts of two adjoining pedicles were removed and the VA was occluded by a small hemoclip.

RESULTS

The vertebral artery was successfully occluded in 36 experimental animals. In 22 animals the occlusion was confirmed.

CONCLUSIONS

The technique proved to be very reliable and rather easy. Its main advantage seems to be the possibility of simultaneous access to vertebral and carotid arteries.

Surgical approach to the rabbit sciatic nerve. Technical note

A description with anatomical pictures of a simple and gentle dorsolateral approach to the rabbit sciatic nerve are presented. Blunt separation of the septum between the semitendinosus muscle and the caput pelvinum bicipitis femoris muscle, allows for excellent access to the nerve along a considerable length. The dorsolateral subfascial vein of the thigh is an easily identifiable landmark of this septum. This gentle approach ensures very smooth healing.

Comparison of microsurgical suture with fibrin glue connection of the sciatic nerve in rabbits

The regeneration of the sciatic nerve after microsuture was compared with the connection of transected nerve with a coagulum of autologous blood plasma in 20 rabbits. The epineuroperineural suture was performed in 10 rabbits (group A). The severed nerve was approximated with fibrin glue of autologous blood plasma in 10 rabbits (group B). Their skin sensation margin during a 3-month-period of regeneration was examined, 90 days after surgery the connection was inspected and the nerve conduction velocity was measured across the site of the anastomosis. The microsuture was found to be firm in all 10 animals of group A. On the other hand, in 2 animals of group B, the glue failed to keep the nerve stumps approximated (dehiscence occurred in 20% of the animals). There were no significant differences found on clinical and electrophysiological testing of regenerated nerves of both groups. The method of autologous fibrin glue in the repair of peripheral nerve transection does not provide a sufficiently firm connection. This procedure with the preparation of the centrifuged plasma is a more time-consuming method in comparison with the microsuture. Epineuroperineural microsuture with maximal effort to adapt the corresponding nerve fibres remains the method of choice for peripheral nerve reconstruction.

[Normal pressure hydrocephalus--a rare late complication of radiography of the spine using contrast media]

The aim of the study is to inform professionals about a serious complication--the liquor malabsorption--developing in relation to the routinely performed roentgen-contrastive examination (PMG). It also demonstrates advantages of the lumbal infusion test (LIT) as a part of the algorithm of the shunt operation in patients with supposed pathology of liquor malabsorption.

[Development of peripheral nerve surgery]

In the submitted review the author deals with the development of peripheral nerve surgery (PN) from ancient times to the present time incl. hithero unpublished details. He analyses in great detail the period of the last 40 years which is divided into three stages--the mechanical, biological period and the period of neurotrophism. From the Second World War to the sixties the period bears the term mechanical. The results of reinnervation during this period were not satisfactory as the nerves were connected without the use of a microscope, in major defects they were connected under considerable traction and the only criterion was the resistance against dehiscence. Significant improvement of results of regeneration of PN was recorded during the biological period. Mechanical ideas were overcome and biological and physiological reactions of the peripheral nerves were taken into account. Suture of nerves under traction was refuted and into clinical practice the surgical microscope, microsurgical technique and microsurgical autotransplantation with a nervous graft were introduced. The anatomical structure of the nerve with a plexiform pattern of the fascicles became however the limitation of surgical methods. After discovery of NGF (nerve growth factor) we can speak of the onset of a new period, neurotrophism. In laboratory experiments many substances are studied and theoretically new non-surgical possibilities how to promote regeneration lie ahead. However they cannot be applied yet in clinical practice. In injuries of peripheral nerves the only correct reconstruction method is still microsuture of the nerve and in case of losses microsurgical autotransplantation using a nerve graft.

[Microsurgical Technique in Injuries of Pheripheral Nerves Part II: Experimental Study (Comparison of Microsuture with the Technique of Gluing by Means of Plasma Coagulum of the Ischiadic Nerve).]

In a group of 20 rabbits the authors compared regeneration of the nervus ischiadicus after microsuture and after gluing the severed nerve with plasma coagulum. In 10 rabbits of group A epineural suture was performed, in 10 rabbits of group B the severed nerve was glued with autologous plasma coagulum. During a three-month regeneration period the authors examined the threshold of sensation 90 days after surgery the anastomosis was examined and also the rate of conduction across the anastomosis. Firmness of the suture was proved in 100% (group A), in two glued nerves dehiscence of the anastomosis occurred, the coagulum was found to be firm in 80 % (group B). When the repaired nerves of both groups were examined, no significant difference was found during clinical examination nor in the conduction across the anastomosis. The method of gluing the nerve with plasma coagulum does not ensure sufficient firmness of the anastomosis on traction. As compared with suture, gluing and preparation of centrifuged plasma is a more tedious method. The method of choice for joining a nerve on the extremities remains microsuture with maximal efforts to achieve adaptation of the corresponding nerve fascicles. Key words: rabbit, nervus ischiadicus, regeneration, microsuture, fibrin coagulum.

[Microsurgical technique in injuries of peripheral nerves part I: clinical study.]

The authors evaluate the quality of regeneration following microsurgery of distal injuries of the nervus medianus and ulnaris. For the evaluation of reinnervation proper and comparison with other authors they emphasize the necessity to respect objective criteria of useful recovery, i. e. a two-point discrimination sensitivity test up to 12 mm in the entire autozone of the nerve. The result of the microsuture depend on the surgeon's experience, on the time interval (injury - final operation) and on age. In early operations useful recovery was achieved by 45 % of the patients of all age groups. In late operations useful recovery was achieved only by 19 % patients, moreover only by patients under 30 years of age. The main prerequisite of high-standard regeneration is early diagnosis and an acute microsurgical operation in a specialized department. Key words: nervus medianus, nervus ulnaris, injury, regeneration, microsurgery.

[Results of regeneration after peripheral nerve injuries]

Based on a group of distal injuries of the median and ulnar nerve the authors evaluate the results of peripheral nerve regeneration. For evaluation of the results and comparison with other work they emphasize the necessity of adherence to objective criteria of a useful degree of reinnervation. In their opinion the most suitable criterium is evaluation of sensitive reinnervation respecting the discrimination test up to 12 mm in the entire autozone of the nerve. The results of suture depend on the technique, interval (injury-operation) and the patient's age. In acute operations 45% of the patients of all age groups achieved the useful grade of sensitive regeneration. In late operations, where the degree of useful regeneration was achieved only in 19% of patients, the authors draw attention to the fact that a successful outcome was achieved only in patients under 30 years. The main prerequisite of successful regeneration of peripheral nerves in according to the authors early diagnosis and treatment in the acute period. With regard to the declining regeneration potential with advancing age early treatment is much more important in patients older than 30 years. Microsurgical technique is a condition sine qua non.