Stanislav Němeček

Detailed evaluation of 2959 allogeneic and xenogeneic dense connective tissue grafts (fascia lata, pericardium, and dura mater) used in the course of 20 years for duraplasty in neurosurgery

SummarySurgical experience with 2959 allogeneic and xenogeneic dense connective tissue grafts (1767 of fascia lata, 909 of pericardium, and 283 of dura mater), used in 2665 neurosurgical operations performed in the course of 20 years (1976 to 1995) is reported.Duraplasty using either allogeneic or xenogeneic grafts has had a similar, and favourable clinical outcome. Nevertheless, the pliable deep frozen fascia lata grafts, which could be used in any location, have been reserved for sella turcica plugging, anterior cranial base plasty, aneurysmal wrapping, and surgery of lipomyelomeningocele. Pericardium and dura mater grafts were in the majority of cases used over the brain convexity and posterior cranial fossa. Ovine pericardium proved to be superior to bovine and allogeneic pericardia because of its workability, flexibility, reduced thickness, and better transparency.Postsurgical complications occurred in 7.3%, and they were: 1) cerebrospinal fluid fistulas in 2.8%; 2) meningites in 2.3% (aseptic 1.4%, bacterial 0.8%, and tumoural 0.1% meningites); 3) pseudomeningoceles in 2.2%; 4) wound infections in 0.6%; 5) malresorptive hydrocephalus in 0.5%; and 6) adhesions to nerve tissue in 0.5%. The majority of complications healed without surgery. Forty-eight grafts (1.6%) failed to fulfil the requirements of the surgeon, and 46 of them were re-operated upon. Though another thirty-nine grafts healed successfully, 39 shunts (1.5%) had to be performed for malresorptive hydrocephalus (0.9%), and/or for a big pseudomeningocele (0.6%). So, the pure complication rate in 2665 duraplasties was 3.1%.The complex evaluation of the allogeneic and xenogeneic grafts (fascia, pericardium, and dura mater), used for duraplasty in neuro-surgery during the last 20 years proved them, as remarkably good, with a success rates of 96.9%.

Posterior cranial fossa surgery in 454 children Comparison of results obtained in pre-CT and CT era and after various types of management of dura mater

Abstract At the Department of Neurosurgery, Hradec Králové, 454 children (aged under 18 years) were operated on for posterior cranial fossa lesions in a period of 49 years (1948–1996). The majority (402) had tumours: cerebellar astrocytomas 149 (37.1%), medulloblastomas 139 (34.6%), brain stem gliomas 46 (11.4%), ependymomas 28 (7.0%), and others 40 (9.9%). Postoperative mortality was compared for the pre-CT era (1948–1977) and the CT era (1978–1996): astrocytomas (8.6%:4.7%), medulloblastomas (14.9%:2.9%), brain stem gliomas (21.7%:19.0%), ependymomas (18.2%:6.3%), and others (40.0%:7.4%). The initially high mortality was due to insufficient intracranial decompression, brain oedema and disturbances of cerebrospinal fluid circulation. Obstructive hydrocephalus was treated in 53 children with tumours and 25 with aqueduct stenoses, by Torkildsens drainage in 5.5%, and/or by catheterisation of aqueduct in 12.3%. The main postoperative complications of medial posterior fossa surgery in 429 children operated on were: pseudomeningocele (12.3%), active hydrocephalus (6.2%) and CSF leakage (4.6%). Only 8.2% had shunts placed for these complications. We presume that this low percentage of shunts used results from a frequent use of duraplasties and drains installed at the primary operation. The dura mater was initially (1948–1954) left open (50 cases), and later (1955–1958) also sutured (37 cases), and from 1958, onward, and especially from 1961, reconstructed by a medial approach by means of various grafts (377 cases). In all, duraplasty was performed in 81.6% of cases. The grafts used for dura mater reconstruction were prepared from autogeneic (1.6%), allogeneic (72.3%), xenogeneic (24.8%), or synthetic (1.3%) material. They were successful in 99.2% of cases (all materials). Our own suture technique for posterior fossa duraplasty is presented.

Choroid plexus cyst of the left lateral ventricle with intermittent blockage of the foramen of Monro, and initial invagination into the III ventricle in a child

Abstract A cyst of the choroid plexus of the left lateral ventricle with intermittent blockage of the foramen of Monro and initially with invagination of the III ventricle in a child is described. In a 6-week-old boy a ventriculoatrial shunt was implanted for correction of an active asymmetrical hydrocephalus of unknown origin. When he was 3 months of age a water-soluble contrast CT ventriculography revealed a noncolloid cyst localised predominantly in the upper portion of the III ventricle. At that time the ventricular catheter obstructed with choroid plexus was removed; new bilateral catheters in a parieto-occipital region were implanted. In the course of the next 4 years, first the atrial catheter had to be extracted and then the peritoneal catheter was changed, in both cases because of obstruction. Periods of normal life alternated with periods of transient and intermittent symptoms of increased intracranial pressure, papilloedema, and myoclonic jerks. Repeated computed tomography (CT) and magnetic resonance imaging (MRI) showed stabilised hydrocephalus with an enlarged left lateral ventricle. When the boy was 16 years old MRI revealed a choroid plexus cyst in the left lateral ventricle 2 cm in diameter, with a ball-valve type of obstruction of the foramen of Monro. CT stereoendoscopic resection of the wall of a large cyst filled with cerebrospinal fluid was performed, and two additional adnexal small cysts were coagulated using the bipolar coagulator, Diomed 25 laser and scissors; the symptoms then regressed, except for superior bilateral altitudinal anopsia. Light and electron microscopy of the cyst wall is reported. The cyst was composed of collagenic connective tissue lined with a basal lamina lacking in epithelial cells. The preoperative and postoperative MRI are presented. Choroid plexus cysts localised in the anterior part of lateral ventricles are very rare, and all reported cases have been in male patients. According to the literature our case is only the third ever described in a child.

Posterior fossa duraplasty in children: remarks on surgery and clinical and CT follow-up

A series of 314 posterior fossa duraplasties in children were performed at the Department of Neurosurgery, Hradec Králové, over the past 33 years. Computed tomographic (CT) imaging was used to compare the healing of various kinds of collagenic dural substitutes — allogeneic fascia lata, allogeneic dura mater and xenogeneic pericardium. Early (8 days to 3 months following surgery) and late (1–18 years following surgery) axial CT scans with sagittal reconstruction for duraplasty in 55 children were evaluated. In early postoperative CT scans, epidural collections of cerebrospinal fluid, sanguinolent liquid or haematoma and/or pseudocysts or pseudomeningoceles appeared. In late CT follow-up, calcifications and ossifications in the “suboccipital coverings complex” (SCC) gradually developed and pseudocysts or pseudomeningoceles rarely persisted. It is concluded, on the basis of perioperative, clinical, and CT examinations, that posterior fossa duraplasties in children formed an important anatomical barrier and regardless of the type of graft had a favourable outcome; CT was shown to be a suitable method for the demonstration of dural grafts at the site of craniectomies.

Mature sacrococcygeal teratoma containing the lower half of a human body

Twins were diagnosed by ultrasound in a 29-year-old woman. The cesarean delivery revealed at first a mature girl with a large benign sacrococcygeal teratoma and then a healthy boy. X-ray and CT examinations of the teratoma showed pelvic and lower limb bones. A mature teratoma-tridermona (weight 475 g) containing the underdeveloped lower half of a human body was confirmed during surgery and verified morphologically. The fraternal twins, i.e., the girl operated upon and her brother, have been followed for 5 years and are without any complaints. They have normal neurological function.

Congenital dermoid cysts over the anterior fontanel

The authors report on 13 cases of dermoid cysts over the anterior fontanelle in Czechoslovak children. These children were 2–19 months of age; with a male-to-female ratio of 2:1. The cyst sizes ranged from 10 to 30 mm. Hence, the number of cases published in the world so far in children has increased to 174. Simultaneously, the number of European cases has increased to 30 (17.2%). Nevertheless, the dominance of the reported cases is still 74 in America (42.5%) and 45 in Africa (25.9%).

An impregnation technique for studying distribution of mitochondria in central nervous system.

SummaryAn impregnation technique for demonstration of mitochondria in central nervous system has been described. Formol perfused material is being chromated, embedded in paraffin and impregnated with a modified Nautas method. The reaction is specific since reduced silver particles are deposed within the matrix of mitochondria. Phenomenon of complete and incomplete impregnation is discussed. Mitochondria in perikarya of neurons, dendrites and glia tend to be unstained if the impregnation is incomplete, while axonic and praesynaptic ones are labelled. In neuropil of different regions of the brain various types of mitochondrial aggregates appear in complete impregnation. The method may be a valuable tool for studying brain architecture and synaptology.

Benign cyst of the paramedian pontine tegmentum

A benign ovoid cyst, without an epithelial lining, localized in the paramedian pontine tegmentum, was examined by computed tomography (CT) and magnetic resonance imaging (MRI) (25×15×15 mm) and successfully operated upon. The one-and-a-half syndrome (horizontal gaze palsy to the right and paralysis of adduction of the right eye) and ipsilateral “peripheral” VII nerve palsy dominated the clinical picture. Fenestration, 5 mm in diameter, of the cyst wall through the floor of the IV ventricle was performed and 2.6 ml of clear, colorless fluid was evacuated. Inspection of the cyst, using the operating microscope, revealed a smooth, white, glistening cavity with no evidence of other pathological tissue. Duraplasty was performed with allogenic pericardium. Neurological symptoms improved immediately after surgery. Light and electron microscopy of the cyst wall revealed a fibrillar astroglial network and fragments of ependyma at the ventricular side of the biopsy.