Experimental study and clinical use of poly(vinyl acetate) emulsion as liquid embolisation material

A new material, an emulsion of poly(vinyl acetate) was experimentally developed and clinically used to overcome several disadvantages in currently used liquid embolisation materials. The emulsion microparticles, 0.3–0.7 m in size, possessed cationic charge on the surface and hence aggregated immediately on contact with fluids containing anions. This inert polymer has the advantage that it does not induce a deleterious reaction in living tissue. Moreover, its medium is water and it is not adhesive, like the cyanoacrylates. Several concentrations of emulsion were injected into the renal arteries of dogs. For the investigation of tissue reactions and the possibility of recanalisation, the emulsion was injected into rats both subcutaneously and into the renal arteries. The renal artery injections in dogs showed adequate radiopacity and consistent complete occlusion. The lower the concentration of the emulsion, the smaller the arteries which could be occluded. Even at very low concentrations, however, venous occlusion did not occur. Histological study of the embolised rat kidney revealed no detectable damage in the vessel wall and no recanalisation for up to 6 months. The subcutaneously injected PVAc emulsion elicited mononuclear cell infiltration and gradual centripetal fibrosis, without any deleterious effect on the surrounding tissue. A cerebral arteriovenous malformation (AVM) was embolised using the material. Histology of the resected nidus showed findings similar to those in the animal experiments.     

Prognostic value of the Spetzler's grading system in a series of cerebral AVMs treated by a combined management

Summary The prognostic value of the Spetzler's grading system is studied in a series of 52 AVMs treated by a combined management, using one or several of the 3 available techniques: surgical resection, endovascular embolization, radiosurgery.The symptoms at the time of treatment were haemorrhage 50%, seizures 31%, headache and deficit 19%. Three grade groups were considered: I and II (31%), III (33%), IV and V (36%). Overall, AVMs were managed as follows: resection alone 25%, embolization plus resection 23%, embolization alone 23%, radiosurgery with various combinations 29%. According to the grade groups, the most frequently used technique was resection alone for grade I–II AVMs (44%), radiosurgery for grade III AVMs (41%) and embolization alone for grade IV–V AVMs (42%).The clinical outcome was evaluated in terms of deterioration due to treatment. The best results were obtained in grade I–II AVMs (81% with no deterioration) then in grade III AVMs (65%) and in grade IV–V (58%). However, when we consider the outcome in terms of favourable results (no or only minor deterioration) we obtained a similar outcome for grade I–II and grade III AVMs (94% each), and only 79% for grade IV–V malformations. The angiographic outcome showed a better eradication rate in grade III AVMs (88% complete eradication), than in grade I–II AVMs (75%) and in grade IV–V (47%).Our conclusion is that the Spetzler's grading system in this series was well correlated with both the clinical and the angiographic outcome. However, we found no real difference between grade I–II and grade III AVMs. So, in terms of prognostic value, the grade I, II, and III AVMs could be considered together as low-grade malformations, with a better prognosis than the high-grade malformations (grade IV and V).     

脑动静脉畸形影像学诊断方法的评价

目的评价数字减影血管造影（ＤＳＡ）、磁共振成像（ＭＲＩ）及磁共振血管造影（ＭＲＡ）在脑动静脉畸形（ＡＶＭ）诊断中的价值。②方法对病理证实的１１３例ＡＶＭ病人皆行ＤＳＡ及ＭＲＩ检查,其中６７例行ＭＲＡ检查。③结果ＤＳＡ表现为密集成球、相互交叉缠绕的血管团或块状血管;ＭＲＩ表现为蜂窝状、葡萄状和条索状流空血管,无明显占位效应;ＭＲＡ显示局部纡曲的血管团,血管分支增多,缠绕在一起。ＤＳＡ及ＭＲＩ对ＡＶＭ的诊断率远高于ＭＲＡ（χ２＝１０６．７,Ｐ＜０．０１）。④结论ＤＳＡ与ＭＲＩ结合使用,对ＡＶＭ的诊断及治疗有重要价值。ＭＲＡ可作为ＭＲＩ的补充用于筛选及ＡＶＭ切除术后随访检查。     

Case-control study of congenital malformations

To determine potentially teratogenic influencies in Belgrade, a group of 113 mothers who gave birth to severely malformed infants and a control group of 195 mothers with normal infants were interviewed using a structured questionnaire.Statistically significant differences between the two groups were found in the mother's family history of congenital malformations (P < 0.05) and the mother's diseases during the pregnancy (P < 0.01). Infections in the first trimester were particularly more prevalent in case mothers (OR = 7.70; P < 0.01). Mothers did not differ significantly according to exposure to organic solvents, supportive therapy during the pregnancy, use of oral contraceptives, or other personal habits.Corresponding author.     

Craniocervical junction malformation treated by transoral approach. A survey of 25 cases with emphasis on postoperative instability and outcome

Summary An experience with 25 consecutive cases of craniocervical junction (CCJ) malformations operated upon via the transoral route is reported. Twenty-two patients also underwent posterior occipitocervical stabilization with alloplastic material and in only one patient was transoral odontoidectomy and fusion with bone autograph performed.Indication for the transoral route consisted of an irreducible ventral compression of the cervicobulbar junction by the abnormal bone complex.Two patients died during the early postoperative period and the remaining 23 survivors were followed for an average of 3.5 years: 17 of these showed marked improvement and 5 a stabilization of the neurological disturbances. A further patient, who refused posterior stabilization, eventually died because of progressive cranial settling.Long-term results have shown this approach to be decisive in the surgical management of well-selected CCJ anomalies.     

Dandy-Walker malformation: analysis of 38 cases

Thirty-eight cases of Dandy-Walker malformation (DWM) are presented. A female predominance of 3:1 was found. Thirty-two cases (84%) were diagnosed within the 1st year of life. Of these, 17 cases (44.7%) were diagnosed at birth. Ten (26%) were delivered by cesarean section. Thirteen infants (34%) had a birth weight below 3000 g. Several associated malformations were observed, the most frequent being capillary angioma (6 case); cardiac malformations, ophthalmic anomalies, agenesis of the corpus callosum, malformed limbs, and occipital meningocele were also seen. These observations indicate that DWM represents a disorder of the midline central nervous system indicative of marked genetic and etiologic heterogeneity with the possibility of showing clinical and pathological alterations intra-and extracranially. Macrocephaly was the most frequent physical finding, appearing in 31 cases (82%). Seventeen (44.7%) patients died, 11 before 6 months of age, 3 between 6 and 12 months, and 3 after 1 year. Postmortem studies were performed in 13 patients. Three cases have been lost to follow-up. Mental retardation (IQ below 70) was found in 11 cases (58% of survivors), low intellect (IQ between 70 and 85) in 4, and only 2 patients showed normal intellectual development (IQ more than 85). The high incidence of malformations having several genetic and environmental origins, as well as the high early mortality of patients with DWM, indicate the complexity of this syndrome, which involves the midline developmental field structures. It is not an isolated malformation of the posterior fossa in most cases.     

The natural history of familial cerebral cavernomas: a retrospective MRI study of 40 patients

Our objective was to determine the natural history and prognostic factors of familial forms of cerebral cavernous malformations (CCM). Cavernomas are one of the most common central nervous system vascular malformations. Familial CCM is increasingly diagnosed, but little is known about its natural history. In a national survey, we analysed clinical and MRI features of 173 patients from 57 unrelated French families. Of these 40 had undergone at least two clinical and MRI examinations. Occurrence of haemorrhage, new lesions, change in signal intensity and size of lesions have been studied by comparison between first and last MRI studies. The CCM were classified according to Zabramski et al. Mean follow-up was 3.2 years (range 0.5–6.5 years). We followed 232 cavernomas (mean 5.9 per patient, range 1–17). Serial MRI demonstrated changes in 28 patients (70 %). Bleeding occurred in 21 lesions (9.1 %) in 14 patients (35 %). The haemorrhagic risk was 2.5 % per lesion-year, higher in type I and brain-stem CCM. We saw 23 new lesions appear in 11 patients (27.5 %), with an incidence of 0.2 lesions per patient year. Signal change was observed in 11 patients (27.5 %), in 14 lesions (6 %), while 9 lesions (3.9 %) in 9 patients (22.5 %) changed significantly in size. Received: 20 May 1999/Accepted: 1 September 1999     

小儿先天性动静脉瘘的诊治

目的 探讨对小儿先天性动静脉瘘(congenital arteriovenous fistula，CAVF)的诊断与治疗。方法 本组共收治15例CAVF患儿，男6例、女9例，年龄8～14岁。对全部患儿行多普勒超声，动脉造影或MRA检查。发现病变局限者5例，病变范围广泛性者10例，病变大多发生于四肢。动脉造影显示：动静脉之间出现瘘支；动脉分支多而紊乱，可呈碗蜒扭曲状，病变多为弥漫性；静脉象早期出现。对11例患儿行手术治疗，其中4例局限性病变者行病灶切除。对7例病变广泛者行1或多次减量手术，方法是沿动脉主干切除瘘支与病变组织，对分流量大又无法切除的病变组织予以缝扎，以减少分流量。对5例患儿行栓塞治疗(其中2例为术前栓塞治疗以减少手术出血)。1例未治疗。结果 随访1～6年。5例局限性患儿中3例治愈，2例病情控制。10例广泛性病变中，5例病情好转或控制，5例病情仍继续发展。结论 影像学检查是CAVF诊断与治疗的依据。CAVF治疗困难。尤其对广泛性病变者，无论手术或栓塞治疗疗效均欠理想。但对小儿CAVF应尽早治疗，这样可控制病情发展．防止并发症发生。     

DNA Fragmentation in Central Nervous System Vascular Malformations

Recent studies have shown that apoptosis plays an important role in vascular remodeling. We examined central nervous system vascular malformations for the presence of DNA fragmentation which is the evidence of apoptosis. We hypothesize that vascular remodeling through apoptosis may be responsible for recurrence or hemorrhage in these lesions. We examined the specimens of central nervous system vascular malformations by in situ end labeling (ISEL) of fragmented DNA. Moreover, we examined the expression of Caspase-3 which is apoptosis-related proteins in these lesions by immunohistochemistry. DNA fragmentation was observed in all 15 arteriovenous malformation (AVM) specimens. ISEL-positive cells were mainly distributed in the endothelium, media and perivascular tissue. In cavernous hemangioma (CH), DNA fragmentation was also observed in all 5 specimens. ISEL-positive cells were distributed in the endothelium, subendothelium and intercavernous matrix. Thirteen out of 15 AVM lesions stained positive for Caspase-3. Caspase-3 immunoreactivity was mainly distributed in the endothelium, media and perivascular tissue. This distribution was similar to that of ISEL positive cells. As for CHs, all 5 lesions stained positive for Caspase-3. Caspase-3 immunoreactivity was distributed in the endothelium, subendothelium and intercavernous matrix. Our findings indicate that apoptotic cell death and vascular remodeling play a role in the development and maintenance of vascular malformations.