Operative anatomy and classification of the sylvian veins for the distal transsylvian approach

Methods for preservation of the sylvian veins in the transsylvian approach have not been established because of the considerable variations. This study attempted to classify the sylvian veins to facilitate systematic dissection of the sylvian fissure for sylvian veins to be preserved. The operative anatomy of the sylvian vein was examined in 82 hemispheres. The type of drainage and the pattern of branching were investigated. The superficial sylvian vein (SSV) was classified into three types according to the number of stems draining into the dural sinus on the inner surface of the sphenoid bone: The SSV was absent or hypoplastic in eight cases, the SSV was single in 38 cases, and the SSV was double in 36 cases. The SSV drained into neither the sphenoparietal sinus nor the cavernous sinus in nine cases. An anastomosis between the SSV and the deep middle cerebral vein (DMCV) was observed in 42 cases. The frontobasal bridging vein (FBBV) drained into the sphenoparietal sinus in 47 cases. The type of connection was further subdivided into four types according to the connections with the DMCV and FBBV. The venous anatomy of sylvian fissure indicates that dissection (skeletonization) of the main stem of sylvian veins from the temporal lobe should be performed to preserve the tributaries from the frontal lobe.     

Detection of the venous system of the skull base using three-dimensional CT angiography (3D-CTA): utility of the pterional and anterior temporal approaches

Three-dimensional CT angiography (3D-CTA) and digital subtraction angiography (DSA) were compared as means for imaging the skull base venous system. 3D-CTA and DSA were performed on 209 sides of 109 patients to visualize the superficial Sylvian vein (SSV), deep middle cerebral vein (DMCV), and basal vein of Rosenthal (BVR). 3D-CTA clearly visualized the SSV, especially when it coursed along the middle cranial fossa, and flowed into the transverse sinus. However, 3D-CTA could not confirm the point of flow into the sphenoparietal sinus (SPS), cavernous sinus (CS), or pterygoid plexus. 3D-CTA was superior to DSA for delineating the flow of the insular vein or DMCV into the SPS, CS or BVR. The flow of the DMCV passed through the uncal vein into the SPS or CS in more than 60% of the cases, but into the BVR in only a few cases. The flow of the BVR passed into great vein of Galen in about half of the cases, and into the CS through the DMCV in almost all the others. The 3D-CTA provided excellent delineation of veins and their stereoscopic anatomical relationships with the bone structure or the arteries and it must be useful for landmarking and kind of venous treatment during operation. 3D-CTA is potentially a powerful means for operative planning of the pterional and anterior temporal approaches.     

Cerebral vein disorders and postoperative brain damage associated with the pterional approach in aneurysm surgery.

The possible causes of postoperative brain damage were examined in 100 cases of cerebral aneurysms operated on by the pterional approach. Postoperative brain damage occurred in 15% of cases, located mostly in the inferior frontal lobe. Its incidence was higher in early than in delayed operation and increased with severity of preoperative clinical conditions but not correlated with patient age and aneurysm location. The venous perfusion patterns in the inferior frontal lobe were classified into three types based on preoperative venograms: Sylvian type drained mainly into the superficial Sylvian veins (SSVs), Frontal type drained mainly into the frontal bridging veins, and Intermediate type. Postoperative brain damage was most frequent in the Sylvian type with statistical significance (p < 0.01). The brain retraction procedure impairs regional cerebral blood flow (rCBF). Venous congestion in the retracted inferior frontal lobe, caused by stretching and narrowing of SSVs due to both brain retraction and dissection of the Sylvian fissure, also reduces rCBF. Thus, a marked reduction in rCBF in the retracted area causes postoperative brain damage. Postoperative venograms showed the SSVs to be obscured in 24% of patients, indicating that the pterional approach possibly influences the SSV perfusion. A venous perfusion disorder during the pterional approach is the most important factor in postoperative brain damage, and careful preoperative assessment of cerebral veins is indispensable.     

Evaluation of venous system with 3D-CTA--from the viewpoint of treatment to cerebral aneurysm]

BACKGROUND AND PURPOSE: Recently, many reports have suggested that cerebral aneurysms can be treated under diagnoses based only on the information obtained from three-dimensional CT angiography (3D-CTA). However, these reports have mainly emphasized the excellence of the stereoscopic images of aneurysms and the relationships with the arteries, and almost never discuss the venous information. The present study used 3D-CTA images to evaluate potential problems in the venous system which may affect the pterional approach. PATIENTS AND TECHNIQUE: This study included 500 sides of 250 patients who underwent screening for cerebrovascular diseases by 3D-CTA. The voxel-transmission method was used for 3D reconstruction. 3D-CTA images in axial stereoscopic views were mainly evaluated, with views in other directions. RESULTS: The variations of the superficial middle cerebral vein draining the sphenoparietal sinus and cavernous sinus were related to the operative view to assess the potential for venous damage. Potential locations of venous damage to the basal vein include the veins of the first segment draining from the frontal base, the direct communication of the basal vein with the sphenoparietal sinus or cavernous sinus, and the veins of the first segment which independently form the uncal vein draining the sphenoparietal sinus or cavernous sinus. CONCLUSION: 3D-CTA demonstrates the venous system and the spatial relationships with other structures clearly. Such information will help neurosurgeons to construct a better and safer microdissection plan, which will preserve the venous system and help prevent postoperative neurological deficits.     

Microsurgical anatomy of the superficial veins of the cerebrum

The microsurgical anatomy of the superficial cortical veins was examined in 20 cerebral hemispheres. The superficial cortical veins are divided into three groups based on whether they drain the lateral, medial, or inferior surface of the hemisphere. The veins on the three surfaces are further subdivided on the basis of the lobe and cortical area that they drain. The superficial cerebral veins collect into four groups of bridging veins: a superior sagittal group, which drains into the superior sagittal sinus; a sphenoidal group, which drains into the sphenoparietal and cavernous sinuses on the inner surface of the sphenoid bone; a tentorial group, which converges on the sinuses in the tentorium; and a falcine group, which empties into the inferior sagittal or straight sinus or their tributaries. The superior sagittal group drains the superior part of the medial and lateral surfaces of the frontal, parietal, and occipital lobes and the anterior part of the basal surface of the frontal lobe. The sphenoidal group drains the parts of the frontal, temporal, and parietal lobes adjoining the sylvian fissure. The tentorial group drains the lateral surface of the temporal lobe and the basal surface of the temporal and occipital lobes. The falcine group drains an area that includes the cingulate and parahippocampal gyri and approximates the cortical parts of the limbic lobe of the brain. The relationship of these veins to the venous lacunae was also examined.     

Dissection of the Sylvian Fissure in the Trans-sylvian Approach Based on the Morphological Classification of the Superficial Middle Cerebral Vein

The superficial middle cerebral vein (SMCV) is one of the main factors that can impede a wide opening of the sylvian fissure. To reveal the most efficient SMCV dissection for a wide operative field while preserving the veins in the trans-sylvian approach, we retrospectively investigated the SMCVs through intraoperative video images. We characterized the SMCV as composed of the frontosylvian trunk (FST; receiving frontosylvian veins [FSVs] or parietosylvian veins [PSVs]), the temporosylvian trunk (TST; receiving temporosylvian veins [TSVs]), and the superficial middle cerebral common trunk (SMCCT; receiving both FSV/PSV and TSV), and classified the SMCVs of the 116 patients into 5 types based on the morphological classification of the SMCV. Type A SMCV (60.4%) with the SMCCT anastomosed to the frontal side had few bridging veins (BVs) between the SMCCT and the temporal side during dissection. Type B (7.8%) had the SMCCT with no anastomoses to the frontal side. In Type C (17.2%) consisting of the FST and TST and Type D (12.9%) with a merging of the vein of Trolard and Labbé posteriorly and the SMCVs dividing into the FST and the TST again proximally, there were few BVs between the FST and the TST during dissection. Finally, in Type E (1.7%) showing an undeveloped SMCV, there were no BVs between the frontal and the temporal lobes. Postoperative venous infarction occurred in 2.6%. Morphological classification of the SMCV can inform appropriate dissection line to create a wide operative field while preserving the veins in the trans-sylvian approach.     

Unusual intra- and extracranial arteriovenous communication--case report.

The authors report an unusual case of arteriovenous communication between extracranial and intracranial vessels, accompanied by incidentally detected bilateral arachnoid cysts of the middle cranial fossa. A 52-year-old male was admitted with a sudden onset of headache, vomiting, and conjunctival hyperemia of the right eye followed by progressive chemosis and proptosis. He had undergone a craniotomy for hypertensive right putaminal hemorrhage 4 months previously. Angiography showed the main feeding artery to be the superficial temporal artery and the draining veins to be the superficial Sylvian veins and the basal vein of Rosenthal. Partial obstruction of the right cavernous sinus was also shown. At surgery, granulation tissue continued to the dura mater through the skull aperture of previous craniotomy and adhered to the underlying damaged cerebrum. The extremely unusual nature of the communication, the operative findings, and the atypical fistulous figures suggested that communication had occurred postoperatively via newly generated vessels in granulation tissue.     

Dural arteriovenous fistulas of the cavernous sinus with onset of intracerebral haemorrhage mimicking hypertensive putaminal hemorrhage

Summary We describe a patient with dural arteriovenous fistulas of the cavernous sinus (CS-dAVFs) who developed an intracerebral haemorrhage (ICH) mimicking hypertensive putaminal haemorrhage. Drainage into the superior ophthalmic vein (SOV) and inferior petrosal sinus (IPS) was not demonstrated on cerebral angiography, and only cortical venous reflux into the Sylvian vein was observed. In cases of venous drainage concentrated on the Sylvian vein, CS-dAVFs could indicate ICH with radiological appearance resembling putaminal haemorrhage.     

Venous aneurysm development associated with a dural arteriovenous fistula of the anterior cranial fossa with devastating hemorrhage--case report

A 67-year-old man presented with devastating intracranial hemorrhage (ICH) from an anterior cranial fossa dural arteriovenous fistula (DAVF). Four years earlier, digital subtraction angiography had disclosed a DAVF at the right anterior cranial fossa fed mainly by the ethmoidal branches of the bilateral sphenopalatine arteries and slightly by the ethmoidal arteries of the bilateral ophthalmic arteries, and drained primarily by the sphenoparietal and cavernous sinuses via two dilated cortical veins and slightly by the superior sagittal sinus via a frontal ascending vein. Three-dimensional computed tomography angiography revealed the development of a venous aneurysm on the main draining vein over a 4-year period, but no other changes. Venous aneurysm development may be part of the natural history of DAVF with cortical venous drainage and may contribute to the occurrence of ICH.     

Prevalence, anatomic patterns, valvular competence, and clinical significance of the Giacomini vein

OBJECTIVE: Coursing the posterior thigh as a tributary or trunk projection of the small saphenous vein (SSV), the Giacomini vein's clinical significance in chronic venous disease (CVD) remains undetermined. This cross-sectional controlled study examined the prevalence, anatomy, competency status, and clinical significance of the Giacomini vein across the clinical spectrum of CVD in relation to the SSV termination. METHODS: One hundred eighty-nine consecutive subjects (301 limbs) with suspected CVD (109 men, 80 women; age, 18-87 years [median, 61 years]) underwent examination, clinical class (CEAP) stratification, and duplex ultrasound determination of the sites and extent of reflux >0.5 sec) and Giacomini vein's anatomy. RESULTS: A Giacomini vein was found in 70.4% of limbs (212 of 301; 95% confidence interval, 65%-75.6%). Extent, pattern, and sites of reflux in all named superficial and deep veins were evenly distributed in limbs with and without a Giacomini vein; perforator vein incompetence in thigh and calf was also balanced (all, P > .2). Giacomini vein had no effect ( P > .2) on SSV termination anatomy, displaying a similar prevalence in classes C(0-6) . In 212 limbs, either as a tributary or trunk projection of the SSV, the Giacomini vein ascended subfascially (n = 210) to the lower (8%; n = 17), middle (47.6%; n = 101), or upper (44.3%; n = 94) thigh, and terminated at the deep system (45.3%; n = 96) and/or perforated the fascia (64.2%; n = 136), to join the superficial system. Giacomini vein morphology was not affected by the SSV termination anatomy and CEAP clinical class. Incompetence was detected less often (P < .001) in the Giacomini vein (4.7%; n = 10 of 212) than in the saphenous trunks cumulatively (53.3%; n = 113 of 212). Yet the odds ratio of Giacomini incompetence was 11.94 (7 of 33 over 3 of 169) in the presence of SSV reflux, and 11.67 (6 of 23 over 4 of 179) when both the great saphenous vein (proximal, proximal plus distal) and SSV were incompetent. CONCLUSION: Found in more than two thirds of limbs, the Giacomini vein has a complex anatomy that is linked vastly to the deep or superficial veins of the posteromedial thigh, but is unaffected by the anatomy of SSV termination and CEAP clinical class. Its presence proved insignificant to the extent, pattern, sites, and clinical severity of venous incompetence, yet the Giacomini vein was far less often susceptible to reflux than the saphenous trunks were. Routine Giacomini vein investigation is not justified in view of these findings. Investigation could be considered selectively in limbs with SSV incompetence, with or without great saphenous vein incompetence, supported by the high odds of concomitant Giacomini vein reflux.     

The pretemporal approach to the interpeduncular and petroclival regions

Summary A pretemporal approach to the interpeduncular and petroclival regions is described.Through a frontotemporal craniotomy based very low in the middle fossa the temporal lobe is completely exposed. The Sylvian, carotid, chiasmatic, and lamina terminalis cisterns are widely opened. The arachnoid fibers between the uncus and the frontal lobe, as well as those binding the temporal lobe to the tentorial edge and to the oculomotor nerve are also separated. The bridging veins from the temporal pole to the spheno-parietal sinus are usually coagulated and sacrificed allowing for posterior displacement of the temporal lobe.The approach combines the advantages of both the classical pterional and subtemporal approaches providing unhindered exposure of the anterior portion of the tentorial incisura in dealing with vascular and tumoural lesions arising at the sellar, parasellar, and interpeduncular regions, and at the superior aspect of the petroclival region.     

Preoperative evaluation of the venous system for potential interference in the clipping of cerebral aneurysm

BACKGROUND: Variations of the venous system affecting the surgical treatment of cerebral aneurysm were evaluated using three-dimensional computed tomography angiography (3D-CTA) to evaluate the essential aspects of preoperative diagnosis. METHODS: This study included 50 patients who underwent clipping of cerebral aneurysm through the pterional and trans-sylvan approaches. The 3D-CTA and operative findings were compared to assess the characteristics of cases in which the veins restrict brain retraction, hinder operative manipulations or require sacrifice because of the position in the operative field. RESULTS: Superficial sylvian veins that restricted brain retraction were identified in 8 cases. The veins entered the cavernous sinus in a relatively high position just below either the sphenoid ridge (superior lateral type) or the anterior clinoid process (superior medial type), and the veins entering at a more medial position were closer to the spatula and tended to be compressed or directly excluded (superior medial type). The inferior medial type did not tend to become tense and so did not restrict brain retraction. The inferior lateral type hardly affected the operative manipulation. The first segment of the basal vein of Rosenthal, the uncal vein entering the cavernous sinus, or the sphenoparietal sinus were located in the operative field in six cases, and affected the manipulation of dissecting arteries, and exposure and clipping of the aneurysm. CONCLUSIONS: 3D-CTA provides essential information for operative planning to protect the venous system during the pterional and trans-sylvian approaches.     

Case of traumatic dural arteriovenous fistula presenting as an acute subdural hematoma and an intracerebral hematoma. A case report

A rare case of traumatic dural arteriovenous fistula presenting as an acute subdural hematoma and an intracerebral hematoma is reported. A 57-year-old man was admitted to our hospital complaining of aphasia and right hemiparesis. A CT on admission demonstrated a left frontotemporal subdural hematoma and an intracerebral hematoma in the left frontal lobe. Left external carotid angiographies revealed a dural arteriovenous fistula, fed by the left middle meningeal artery and draining the middle meningeal vein. A retrograde drainage into the cortical vein was also revealed. The patient had sudden loss of consciousness after cerebral angiography and demonstrated increased subdural hematoma and severe midline shift. We performed emergency decompressive craniectomy, coagulation of the dural vessels, and evacuation of the subdural hematoma. Postoperative left external carotid angiographies revealed the disappearance of the dural arteriovenous fistula. This case suggested a dural arteriovenous fistula, between the middle meningeal artery and the middle meningeal vein close to the sinus (sphenoparietal or superior sagital sinus), and resulted in a subdural hematoma and an intracerebral hematoma, due to the retrograde venous drainage into cortical veins.     

Operative neurosurgery: personal view and historical backgrounds (3). Anterior circulation--pterional approach

Under the title of anterior circulation aneurysms and the pterional approach, followings are presented and emphasized along with mentioning their historical development in our present performance status. Pterional approach: head positioning with Mayfield-Kees fixation apparatus using one pin around the processus matoideus and the other 2 pins on the contralateral side behind the hair line the head turned 30 degrees and reclined chin-up l5-20 grade. Skin incision beginning just in front of the tragus ending up at the midline hair line in a curvilinear fashion always including the superficial temporal artery STA in its frontal branch and the facial nerve (frontal branch) in the skin flap. A muscle fascial preparation is so fashioned such that a strip of myofascial cuff is left at the linea temporalis and the temporal musculature is reflected and retracted towards the postero-basal direction in order to expose the pterion, for which a small short myofascial incision is added parallel to the skin incision towards the tragus up to several cm above it to prevent postoperative trismus. Bone flap is sawed out usually using three burr holes, at the key hole just at the proximal part of the linea temporalis, frontomedially on the squama frontalis and on the sutura squamosa, so that the Sylvian fissure and the superior temporal gyrus are exposed enough for further procedure. The sphenoid ridge is drilled away until the most lateral corner of the superior orbital fissure comes into view. Thus one has drilled away enough to do surgery in question at the skull base even at the time of "angry brain" due to subarachnoid hemorrhage SAH. This procedure can be followed by selective extradural anterior clinoidectomy SEAC in case of necessity. The dura is opened in a curvilinear fashion so that the dura can be reflected over the drilled sphenoid wing and so that the Sylvian fissure and the superior temporal gyrus is exposed for the treatment of aneurysms of the internal carotid artery ICA, of the anterior communicating artery AcomA and the middle cerebral artery MCA. The dural incision is suitable also for doing other surgeries e.g. basilar bifurcation aneurysms and amygdalohippocampectomy AHE. Following points are emphasised in aneurysm surgery at the acute stage of SAH: (1) Artificial hypotension of the systolic pressure down to 100 mmHg. (2) Use of temporary clipping (or trapping) method not only for the management of premature rupture but for complete dissection of aneurysms and for optimal neck clipping. (3) Opening of the lamina terminalis to gain slackness of "angry brain" and to insert an external ventricular drainage at the end of surgery for the intracranial pressure ICP registration and its regulation. (4) Importance of subpial approximation ("subpiale Ann?herung) at the time of aneurysm dissection to take advantage of the strength of the pia mater over (the arachnoid) and the dome of aneurysm. (5) Use of oxycellulose Tabotamp insertion technique between the aneurysm neck and neighbouring perforators to avoid inclusion of the latter ("Mitklippen") at the time of neck clipping. (6) Double clipping method at the time of incomplete neck clipping due to athromatous plaque. Combination of fenestrated clip and standard clip or "puncture and collapse" method at the time of aneurysm incorporation of parent and/or branching arteries. (7) Use of microDoppler to confirm patency of the parent arteries and their branches. For doing surgery of aneurysms of main cerebral arteries following points are discussed: (1) AcomA aneurysms; (a) Aneurysms located lower than 1.5 cm above the level of the anterior clinoid process in the lateral view on digital subtraction angiography DSA can be managed with conventional pterional approach. (b) Usually from the right side (non dominant hemisphere) but in the following situations from the left side: hematoma on the left side, concomitant unruptured aneurysms on the left side, left A1 dominancy at the acute stage of SAH and its dissection is considered to be difficult from the right side. (c) Always rectal gyrus approach to the aneurysm with any direction. This also enables safety subpial approximation "subpiale Annaeherung" to aneurysms. (d) No use of coagulation as much as possible. (2) ICA aneurysms; (a) Performance of selective extradural anterior clinoidectomy SEAC for paraclinoid aneurysms not only for aneurysm dissection but for proximal control. (b) Neither sacrifice nor Mitklippen of the posterior communicating artery at the time of ICA-PcomA aneurysms, not only for the prevention of the PCA infarction in case of its embryonal type but also for the prevention of tuberothalamic infarction due to compromise of the anterior thalamoperforating arteries originating from the PcomA. (c) Dissecting aneurysms of the ICA: difficulties of diagnosis or differentiation from paraclinoid anurysms. Difficulties of optimal direct clipping and resort to trapping or proximal ligation plus bypass. Its predilection site is at the medial anterior wall of the C1 portion but may occur also in any other portion of the ICA. (3) Middle cerebral artery MCA aneurysms; (a) For dissection, superior temporal gyrus ablation is not necessary but opening of the Sylvian fissure by retrograde tracing of a cortical artery on the surface of the temporal lobe. This cortical artery can be used as recipient when a bypass surgery turns out to be necessary with the use of a donor artery from the frontal branch of the STA. (b) Importance of interpreting DSA or 3DCT angiography in regard to whether the aneurysm dome is outside (lateral) or inside (medial) of the MCA bifurcation. This helps in anticipating whether the aneurysm dome or MCA branches come into view first at the time of intraSylvian dissection. (c) In case of presence of aneurysms at the contralateral MCA, accessibility from the ipsilateral side depends on the distance form the midline (for example early bifurcation), the relationship to the sphenoid wing (not below the level of the sphenoid wing) and no strong Sylvian vein darining into the sphenoparietal sinus being in the way.     

肝脏CT影像解读分析系统在规范肝移植技术中的临床应用

目的分析肝移植术前应用肝脏CT影像解读分析系统研究肝静脉合干及其在下腔静脉注入的解剖与分布情况,按肝静脉解剖特征拟定肝移植的技术类型。方法统计武汉大学中南医院和中南大学湘雅三医院2000年5月至2007年8月期间共施行的248例背驮式肝移植患者的手术数据,并根据该248例患者的肝静脉解剖及其注入下腔静脉的数据对肝静脉类型进行分型并命名。另外收集武汉大学中南医院2010年3月至2013年4月期间实施的40例背驮式肝移植患者的术前肝脏CT影像解读分析系统的数据,分析每例患者的肝静脉在第二肝门合干及其注入下腔静脉的解剖情况,并分析肝短静脉在第三肝门注入下腔静脉的解剖情况,最后按笔者肝静脉分型标准在术前对肝脏CT影像解读分析系统的数据进行分型并拟定肝移植技术类型。结果 248例背驮式肝移植患者术中按肝静脉合干及其注入下腔静脉的解剖情况将肝静脉分为5型：Ⅰ型（左中肝静脉合干型）142例（57.25%）、Ⅱ型（右中肝静脉合干型）54例（21.77%）、Ⅲ型（左、中、右肝静脉共干型）14例（5.64%）、Ⅳ型（分别汇入型）34例（13.71%）〔其中ⅣA型16例（6.45%）,为同轴水平汇入;ⅣB型18例（7.25%）,为非同轴水平汇入〕、Ⅴ型（肝段型）4例（1.61%）。40例背驮式肝移植患者的术前肝脏CT影像解读分析系统的数据显示：Ⅰ型24例（60.00%）,Ⅱ型9例（22.50%）,Ⅲ型2例（5.00%）,Ⅳ型4例（10.00%）,Ⅴ型1例（2.50%）,肝脏CT影像解读分析系统的数据得出的肝静脉各型所占比例与笔者肝静脉分型标准中各型所占比例基本吻合。结论根据术前肝脏CT影像解读分析系统的数据确定肝静脉合干与非合干汇入肝后下腔静脉的解剖状况,从而按肝静脉分型标准归类后术前确定背驮式肝移植手术方式（Ⅰ、Ⅱ、Ⅲ型和ⅣA型可常规行经典式背驮式肝移植,ⅣB型和Ⅴ型仅能进行改良式背驮式肝移植或行经典式原位肝移植,亦可结扎或缝扎各肝静脉分支,在供、受体下腔静脉后、前正中行梭形切口或三角形开孔吻合）,为临床术前决策提供重要依据。     

Anterior interhemispheric approach for distal anterior cerebral artery aneurysm surgery: preoperative analysis of the venous anatomy can help to avoid venous infarction

Summary Background. The anterior interhemispheric approach is a well-known operative technique for a distal anterior cerebral artery (ACA) aneurysm. However, a frontal parasagittal bridging vein is occasionally sacrificed in this approach, creating a risk of postoperative venous infarction.Method. To evaluate the risk of venous infarction, the current study investigated the venous phase of preoperative angiograms and postoperative CT scans for 20 patients in whom a parasagittal bridging vein had been sacrificed during the anterior interhemispheric approach. The draining territory index of the sacrificed bridging vein (DTISBV), draining territory index of the adjacent collateral ascending draining veins (DTIADV), and drainage impediment index (DII) were all calculated, plus the development of the superficial Sylvian vein (SSV) was evaluated.Findings. Extensive postoperative venous infarction occurred in two of four patients with an aplastic SSV, for whom the DTISBVs were 41% and 43%, and the DIIs 26% and 37%. Among 16 patients with a normal SSV, two patients suffered postoperative venous congestion, and their DTISBVs were 40% and 50%, and their DIIs 21% and 30%. The other 14 patients without any postoperative venous drainage problems had a lower DTISBV and DII, where the DTISBV was 22.3±6.8% (mean±SD) and the DII 4.3±8.1%.Conclusions. The present results suggest that the venous phase of a preoperative angiogram should be carefully evaluated before distal ACA aneurysm surgery. In particular, a DTISBV and DII over 50% and 30%, respectively, in patients with a normal SSV and over 40% and 25%, respectively, in patients with an aplastic SSV were found to be critical to the production of postoperative venous infarction.     

Variations of hepatic veins: helical computerized tomography experience in 100 consecutive living liver donors with emphasis on right lobe

Anatomical variations in the venous system of liver are not a rarity. A prospective helical computerized tomography (CT) study was undertaken to determine the prevalence of surgically significant hepatic venous anatomic variations among 100 consecutive living liver donors. The studies evaluated the ramification pattern of hepatic veins, the presence of accessory hepatic veins, and of segment 5 or 8 veins (or both) draining into middle hepatic vein. These data obtained by CT influenced surgical planning. Sixty-four donors donated their right lobes and 24 donors, left lateral segments. Only one donor candidate was refused due to combined hepatic and portal venous variations accompanied by multiple bile ducts. Eleven donors were also refused due to reasons other than anatomical variations. Seventeen segment 5 and 17 segment 8 veins draining into middle hepatic vein were anastomosed to inferior vena cava in 23 (36%) of the right lobe liver transplantations. The middle hepatic vein was harvested in only one of the donors. Among the 100 cases, 47 had accessory right inferior hepatic veins, 13 of which were multiple. Twenty-two of the right lobe grafts required surgical anastomoses of these accessory hepatic veins (34%). An isolated hepatic vein anomaly or the presence of accessory hepatic veins are not contraindications to be a living liver donor candidate. However, preoperative knowledge of vascular variations alters surgical management. Helical CT is a valuable tool to delineate the hepatic venous anatomy for surgical planning in living liver donors.     

Transfer of a pedicled venous flap containing perivenous areolar tissue and nerve: an experimental study.

In this paper, we evaluated experimentally the feasibility of transferring a pedicled venous flap with perivenous areolar tissue into an ectopic site and investigated the role of each vein, the perivenous areolar tissue and nerve in the viability of pedicled venous flaps. Three groups of flaps were created using a rabbit-ear model: Group 1 (n = 11), containing perivenous areolar tissue and a draining vein; Group 2 (n = 10), perivenous areolar tissue, a draining vein and nerve; Group 3 (n = 10), only perivenous areolar tissue. Macroscopic, angiographic and histological assessments were performed 14 days after transfer. The total survival areas including superficial necrosis of Groups 1, 2 and 3 were 52.7%, 82.5% and 0%, respectively. There were significant differences in mean survival area and mean total survival area including superficial necrosis between Group 1 and Group 2 (P < 0.05). In contrast, all flaps in Group 3 became necrotic. These data suggest that a preserved vein is the necessary condition, and additional arterial flow through the preserved nerve and a small vascular network within the areolar tissue may play an important role in flap survival.     

"Tangential" resection of medial temporal lobe arteriovenous malformations with the orbitozygomatic approach

OBJECTIVE: Arteriovenous malformations (AVMs) of the medial temporal lobe are usually resected through subtemporal-transcortical approaches that provide a trajectory that is perpendicular to the plane of the AVM. The pterional approach is sometimes used for AVMs in the uncus and amygdala, but it is not recommended for AVMs in the hippocampal region because it provides a "tangential" approach with limited access to posterior feeding arteries and draining veins. The orbitozygomatic approach enhances exposure along this tangential trajectory and was used in a consecutive series of 10 patients to determine its advantages. METHODS: During a 5.7-year period, 43 patients underwent resection of temporal lobe AVMs, 10 of which were located in the medial temporal lobe (amygdala and uncus [Region A] or hippocampus, parahippocampus, and fusiform gyrus [Region B]). AVMs were evenly distributed by region and by hemispheric dominance and included two Spetzler-Martin Grade IV lesions. An orbitozygomatic approach was used in all cases. RESULTS: Complete resection was accomplished in nine patients, and one patient underwent multimodality management with postoperative stereotactic radiosurgery. Good outcomes (Rankin outcome score 相似文献   

The importance of the superficial venous anatomy of the abdominal wall in planning a superficial inferior epigastric artery (SIEA) flap: case report and clinical study

The importance of the venous drainage of the anterior abdominal wall to free tissue transfer in deep inferior epigastric artery perforator flap surgery has been highlighted in several recent publications in this journal, however the same attention has not been given to superficial inferior epigastric artery (SIEA) flaps, in which the flap necessarily relies on the superficial venous drainage. We describe a unique case, in which the presence of two superficial inferior epigastric veins (SIEVs) draining into separate venous trunks was identified. The use of only one trunk led to a well-demarcated zone of venous congestion. A clinical study was also conducted, assessing 200 hemiabdominal walls with preoperative computed tomographic angiography imaging. The presence of more than a single major SIEV trunk was present in 80 hemiabdominal walls (40% of overall sides). There was considerable variability in the source of drainage of the SIEV, draining variably into the deep inferior epigastric vein, the great saphenous vein, the saphenous bulb, a common trunk with the superficial circumflex iliac vein or a common trunk with a second branch of the SIEV. These findings highlight the considerable variation in the number of SIEV trunks as well as their source of regional drainage, and show the importance of consideration of such variation.