Microsurgical anatomy of the insula and the sylvian fissure

OBJECT: The purpose of this study was to define the topographic anatomy, arterial supply, and venous drainage of the insula and sylvian fissure. METHODS: The neural, arterial, and venous anatomy of the insula and sylvian fissure were examined in 43 cerebral hemispheres. CONCLUSIONS: The majority of gyri and sulci of the frontoparietal and temporal opercula had a constant relationship to the insular gyri and sulci and provided landmarks for approaching different parts of the insula. The most lateral lenticulostriate artery, an important landmark in insular surgery, arose 14.6 mm from the apex of the insula and penetrated the anterior perforated substance 15.3 mm medial to the limen insulae. The superior trunk of the middle cerebral artery (MCA) and its branches supplied the anterior, middle, and posterior short gyri; the anterior limiting sulcus; the short sulci; and the insular apex. The inferior trunk supplied the posterior long gyrus, inferior limiting sulcus, and limen area in most hemispheres. Both of these trunks frequently contributed to the supply of the central insular sulcus and the anterior long gyrus. The areas of insular supply of the superior and inferior trunks did not overlap. The most constant insular area of supply by the cortical MCA branches was from the prefrontal and precentral arteries that supplied the anterior and middle short gyri, respectively. The largest insular perforating arteries usually arose from the central and angular arteries and most commonly entered the posterior half of the central insular sulcus and posterior long gyrus. Insular veins drained predominantly to the deep middle cerebral vein, although frequent connections to the superficial venous system were found. Of all the insular veins, the precentral insular vein was the one that most commonly connected to the superficial sylvian vein.     

Extended lateral transsylvian approach for basilar bifurcation aneurysms

The surgical management of aneurysms of the basilar apex is one of the most challenging areas in neurosurgery. Successful treatment of this subgroup of aneurysms is dependent on the mastery of technical nuances that have been pioneered and advanced over the past 4 decades. Although both the traditional transsylvian and subtemporal approaches have distinct advantages, each is associated with significant limitations. In this article, the senior author shares his insights into a hybrid approach: the extended lateral transsylvian approach. This approach combines the assets of the two traditional approaches while eliminating their liabilities.     

The variations of sylvian veins and cisterns in anterior circulation aneurysms

Summary The anatomical variations of Sylvian vein and cistern were investigated during the pterional approach in 230 patients with 276 aneurysms of anterior circulation arteries, that were operated on at the Neurosurgical Department of Atatürk University Medical School, Erzurum, Turkiye. All patients underwent radical surgery for aneurysm by the right or left pterional approach. The findings were recorded during surgical intervention and observed through the slides and videotapes of the operations.In our study, we surgically classified the variations of the Sylvian vein, according to its branching and draining patterns. Type I: The fronto-orbital (frontosylvian), fronto-parietal (parietosylvian) and anterior temporal (temporosylvian) veins drain into one sylvian vein. Type II: Two superficial Sylvian veins with separated basal vein draining into the sphenoparietal and Rosenthal's basal vein. Type III: Two superficial Sylvian veins draining into the sphenoparietal and the superior petrosal veins. Type IV: Hypoplastic superficial Sylvian vein and the deep one. Four types of Sylvian vein variations were defined as follows. The Type I was seen in 45% (n = 103), the Type II was found in 29% (n = 67), Type III was recorded in 15% (n = 34) and Type IV, or hypoplastic and deep form was discovered in 11% (n = 26) of patients. The course of the Sylvian vein was on the temporal side (Temporal Coursing) in 70 percent of the cases (n= 160), on the frontal side (Frontal Coursing) in 19% of the patients (n = 45) and in 8 percent of the cases (n= 18) in the deep localization (Deep Coursing). Only 3 percent of the cases (n = 7) showed a mixed course. The variations of the Sylvian cisterns were classified into three types, according to the relationships between the lateral fronto-orbital gyrus and the superior temporal gyrus. In Sylvian Type, the frontal and temporal lobes are loosely (Sylvian Type A, Large) or tightly (Sylvian Type B, Close and Narrow) approximated on the surface thereby covering the area of the Sylvian cistern. In frontal type, the proximal part of the lateral fronto-orbital gyrus herniated into the temporal lobe. In temporal type, the proximal part of the superior temporal gyrus herniated into the lateral fronto-orbital gyrus. The variations of the Sylvian cisterns in 230 patients were as follows: in 31% (n = 71) Sylvian Type A, in 21% (n = 48) Sylvian Type B, in 34% (n = 78) Frontal Type, and in 14% (n = 33) Temporal Type.We concluded that venous perfusion disorder of the brain is the most important factor during the pterional approach. Careful intraoperative assessment and protection of the Sylvian vein, which is a surgical pitfall, is an indispensable part of the operation. The recognition of the anatomical variations of the Sylvian vein and cistern, and the detailed knowledge of the microvascular relationships at that level will allow the neurosurgeon to construct a better and safter microdissection plan, to save time and can prevent postoperative neurological deficits.     

Image-guided transsylvian, transinsular approach for insular cavernous angiomas

OBJECTIVE: Surgical treatment of cavernomas arising in the insula is especially challenging because of the proximity to the internal capsule and lenticulostriate arteries. We present our technique of image guidance for operations on insular cavernomas and assess its clinical usefulness. METHODS: Between 1997 and 2003, with the guidance of a frameless stereotactic system (BrainLab AG, Munich, Germany), we operated on eight patients who harbored an insular cavernoma. Neuronavigation was used for 1) accurate planning of the craniotomy, 2) identification of the distal sylvian fissure, and, finally, 3) finding the exact site for insular corticotomy. Postoperative clinical and neuroradiological evaluations were performed in each patient. RESULTS: The navigation system worked properly in all eight neurosurgical patients. Exact planning of the approach and determination of the ideal trajectory of dissection toward the cavernoma was possible in every patient. All cavernomas were readily identified and completely removed by use of microsurgical techniques. No surgical complications occurred, and the postoperative course was uneventful in all patients. CONCLUSION: Image guidance during surgery for insular cavernomas provides high accuracy for lesion targeting and permits excellent anatomic orientation. Accordingly, safe exposure can be obtained because of a tailored dissection of the sylvian fissure and minimal insular corticotomy.     

Microsurgical anatomy of the mesencephalic veins

OBJECT: The mesencephalic veins drain crucial brainstem areas. Due to the narrowness of the tentorial notch, these veins can become obstructed as a result of herniation or surgery, leading to hemorrhage and severe consequences for the patient. There is little in the literature about the mesencephalic veins. The aim of this study was to perform an exact analysis of their microanatomy. METHODS: Fifty-two cadaveric hemispheres were examined under an operating microscope, and measurements were made with a digital caliper. The authors focused on the basal vein (BV), pontomesencephalic vein (PMV), peduncular vein (PV), lateral mesencephalic vein (LMV), and other smaller veins. The PMV was identified in 84.6% of specimens (mean diameter 0.54 mm); the PV, in 86.5% (mean diameter 0.86 mm); and the LMV, in 100% (mean diameter 1.07 mm). Four types of LMV were identified on the basis of the vein's course. Other smaller veins were also differentiated according to whether they drained mainly the cerebral peduncle, the lemniscal trigone, or the tectum. These veins and their junctions with other veins were depicted. CONCLUSIONS: A thorough understanding of the microanatomy of the mesencephalic veins is crucial in brainstem surgery in order to avoid brain damage due to venous infarction and subsequent edema. Because knowledge of the course, variations, and outflow system of these veins could improve surgical outcome, they warrant special attention during surgery.     

桡骨远端Barton骨折的手术治疗

目的　探讨桡骨远端Barton骨折的手术方法及疗效观察。方法　对 1999年 6月至 2 0 0 2年3月收治的 2 6例Barton骨折的病人 ,其中背侧Barton骨折 12例 ,掌侧Barton骨折 14例 ,分别进行背侧及掌侧T形纯钛金属板钉内固定 ,术后进行早期功能锻炼。结果　 2 6例全部得到随访 ,术后随访 5～ 18个月。X线片显示桡骨远端骨折全部愈合 ,掌倾角 7°～ 15°,平均 10 .2° ,尺偏角 18°～ 2 7°,平均 2 0 .2°。桡骨轴向无短缩 ,按Mehara关于掌侧Barton骨折功能评价[1],优 18例 ,良 6例 ,可 2例 ,优良率达到 92 .3 %。结论　对于桡骨远端Barton骨折 ,采用T形纯钛金属板钉内固定配合术后早期功能锻炼 ,可达到骨折准确复位及早期恢复腕关节功能的目的     

Novel entry point for intraoperative ventricular puncture during the transsylvian approach

Summary Objective. In dealing with cases of oedematous brain, relaxation during the transsylvian approach to supratentorial aneurysms has been accomplished by ventricular drainage by using the anatomic point defined by Dr. Paine. However, we have experienced patient complications when using this point. We propose a novel anatomic point to reduce catheter-related complications and facilitate adequate ventricular puncture during ruptured aneurysm operations. Methods. Ten patients underwent aneurysmal neck clipping for ruptured aneurysm by means of the transsylvian approach. The use of a novel anatomic point for intraoperative drainage was examined using a neuronavigation system. Results. Using the novel point of entry for ventricular cannulation proved to be reliable for puncture and reduced chance of malpositioning. Conclusion. Secure intraoperative ventricular cannulation is reliably achieved by pointing the catheter approximately 2 cm beyond a line extending from the anterior limb of the triangle described by Paine. This technique reduces injury to the deep brain and enhances preciseness and safety of ventricular cannulation.     

Operative treatment for separation of distal tibiofibular syndesmosis

Objective: To study the influence of separation of distal tibiofibular syndesmosis on ankle joint and to compare various operative methods so as to find suitable stabilization for separated distal tibiofibular syndesmosis. Methods: From July 1997 to July 2002, we treated 87 patients (64 males and 23 females, aged 18-54 years) with separation of distal tibiofibular syndesmosis, among whom, 79 were combined with fracture of malleolus. Manipulative reduction, internal fixation with cancellous screws and external fixation with plaster support were performed on 37 patients, fixation with plate and screws for fibular fracture and fixation with cancellous screws for distal tibiofibular syndesmosis on 34 patients, and repair of the distal tibiofibular ligaments with tendon of peroneus longus, reduction of the separated distal tibiofibular syndesmosis, and fixation with cancellous screws on 16 patients. The ankle joint had been dorsiflexed for 30°when the distal tibiofibular syndesmosis was fixed with cancellous screws. And the cancellous screws were taken out at 8-10 weeks after operation. Results: These patients were followed up for at least two years. The curative effects were assessed according to the complaints of the patients and the contour, function and radiogram of the ankle joint: excellent in 55 patients (63%), good in 18 patients (21%) , and fair in 14 patients (16%). Separation of distal tibiofibular syndesmosis recurred in 2 patients, who underwent a reoperation for repairing the distal tibiofibular ligaments with tendon of peroneus longus and recovered. One cancellous screw was broken off. No necrosis developed in the anterior skin of the ankle mortise. Conclusions:Separation of distal tibiofibular syndesmosis can be treated with various reasonable operations. Repair with tendon of the peroneus longus can get excellent outcomes for complete separation of the distal tibiofibular syndesmosis.     

Ligamentous anatomy of the distal clavicle

We describe the insertional variations of supporting ligaments of the acromioclavicular joint, especially with respect to gender. We analyzed 41 cadaveric clavicles (22 female and 19 male) with attached ligaments. The distance between the insertion of the trapezoid ligament and the distal end of the clavicle was not significantly different between sexes, although that of the conoid ligament and the mean anteroposterior width of the distal clavicle was significantly greater in men. Although there are significant sex-related differences in the insertional distances of the CC ligaments, resection of less than 11.0 mm should not violate the trapezoid ligament and less than 24.0 mm should not violate the conoid ligament in either sex in 98% of the general population. Resection of more than 7.6 mm of the distal clavicle in men and 5.2 mm in women, performed by an arthroscopic approach, may violate the superior acromioclavicular ligament.     

The volar anatomy of the distal radius—An MRI Study of the FCR approach

Introduction

Fractures of the distal radius are one the commonest orthopaedic injuries. Recent advances in implant technology have seen a dramatic rise in the number of fractures treated with volar locked plates, as they permit accurate peri-articular reconstruction. The surgical approach along the bed of flexor carpii radialis (FCR) tendon encounters a number of key soft tissue and neurovascular structures during the dissection to the fracture plane. The aim of this study was to describe the exact position of such structures involved (and hence at risk) during the FCR approach.

Methods

100 adult MRI scans were reviewed. The relationships between the brachioradialis tendon (BR), flexor carpi radialis (FCR) tendon, flexor pollicis longus (FPL) tendon, median nerve (MN) and radial artery (RA) were measured.

Results

The male to female ratio was 35:65. Average age was 39. FCR tendon was 7.4 mm (SD 1.46) from the RA and 7.01 mm (SD 2.37) from the MN. The distance between BR and RA was significantly different between male and female (5.06 mm vs. 4.1 mm, p = 0.034).

Conclusion

This study highlights the precise nature of the surgical anatomy involved in dissection to the fracture site. Vigilance is needed during the initial steps of the FCR-bed approach to avoid damage to the radial artery and median nerve which lie in close proximity. If the approach is extended to include a brachioradialis tenotomy, we suggest this should be made under direct vision, given its relationship with the radial artery.     

Age-related variations of varicose veins anatomy

BACKGROUND: Primary varicose veins are commonly considered a progressive disease starting from the saphenous junctions and extending to tributaries in a retrograde fashion along the saphenous trunks. This theory has been criticized by studies indicating different patterns of development and progression of varicose veins. To contribute to the understanding of the pathogenesis of the disease, the anatomy of the venous bed was comparatively evaluated by duplex sonography in patients with varicose veins with a marked difference in age. METHODS: The study included 100 varicose limbs in 82 patients aged < 30 years and 238 limbs in 183 patients aged > 60 years. Veins were designated as saphenous veins (SVs), tributaries of the SVs (STVs), and veins not connected with the SVs (NSVs). Four main anatomic patterns were comparatively evaluated: (1) varicose changes only along SVs, (2) varicose changes along SVs and STVs, (3) varicose changes only in STVs, and (4) varicose changes only in NSVs. RESULTS: SVs were normal in 44% of varicose limbs. In most limbs from young subjects, varicose changes afflicted only SVTs (25%) and NSVs (36%). Varicose SVs were more frequent in the older group (62%) than in younger one (39%) owing to a higher prevalence of limbs with combined SV and STV varicosities (respectively, 59% and 37%). In the older group, varicosities in the STVs were more frequently observed in association with incompetence of the SV trunks. CONCLUSION: The frequent occurrence of normal SVs in varicose limbs of all patients does not support the crucial role commonly credited to SVs in the pathogenesis of primary varicosities. Moreover, the SV trunks were normal in most varicose limbs from young patients. These findings suggest that varicose disease may progressively extend in an antegrade fashion, spreading from the STVs to the SVs. This hypothesis suggests that the saphenous trunks could be spared in the treatment of a relevant number of varicose legs. Prospective longitudinal studies with serial duplex evaluations of large series of extremities are necessary to confirm this hypothesis.     

Surgical anatomy for endoscopic subfascial division of perforating veins

Purpose: This study was undertaken to define the surgical anatomy of the medial perforating veins (PVs) of the leg and to provide information on how to gain access to all medial PVs from the superficial posterior compartment during a subfascial endoscopic procedure.Methods: The venous anatomy of 40 limbs (from 23 cadavers) were studied. Medial PVs located between the ankle and the tibial tuberosity were dissected. None of the subjects had pathologic evidence of venous disease. Each PV's type (direct or indirect), size (<1 mm, 1 to 2 mm, >2 mm), location (distances from ankle [D1], and tibia [D2]), and accessibility from the superficial posterior compartment were recorded.Results: Five hundred fifty-two PVs were identified (mean, 13.8; range, 7 to 22). Two hundred eighty-seven PVs (52%) directly connected the superficial with the deep systems, 228 (41%) were indirect muscle perforators, and 37 PVs (7%) were undetermined. One hundred thirty-seven PVs (25%) were >2 mm. Sixty-three percent of PVs were accessible from the superficial posterior compartment. In the distal half of the leg, two groups of direct PVs could be identified (Cockett II: D1, 7 to 9 cm; Cockett III: D1, 10 to 12 cm). In the proximal half of the leg, paratibial direct PVs (D2 ≤ 1 cm) were found clustered in three groups (D1, 18 to 22 cm; D1, 23 to 27 cm; D1, 28 to 32 cm).Conclusions: Our study confirmed the presence of the Cockett II and III PVs and three groups of proximal paratibial PVs, including the “24-cm” perforators. Two thirds of the medial direct PVs are accessible for endoscopic division from the superficial posterior compartment. To divide paratibial PVs, however, incision of the paratibial deep fascia is frequently required. (J Vasc Surg 1996;24:800-8.)     

Surgical anatomy of the posterior tibial veins]

An investigation of the posterior tibial vascular plexus has established certain specific features of its structure both in normality and in patients with postthrombotic disease. The alterations found require an individual approach to choice of surgical measures which is finally determined intraoperatively. At the present time surgical interventions on the posterior tibial veins in patients with postthrombotic disease are thought to be of three types: extended resection, extravasal correction and plasty of the posterior tibial veins.     

股骨远端骨折的手术治疗

目的探讨股骨远端骨折的手术治疗方法及合并症的预防。方法对1991年～2001年,348例股骨远端骨折手术治疗,选用螺钉、动力加压钢板(DCP)、角钢板、动力髁部螺钉(DCS)、股骨髁钢板、带锁髓内钉治疗股骨远端骨折。研究内固定物的使用、骨折复位、植骨、骨折不愈合等相关问题。结果13例发生内固定失效、钢板断裂,需要重新固定植骨。8例延迟愈合,二期植骨。其余骨折均愈合。14例术后伤口感染,18例晚期出现肢体短缩,范围1～4cm。52例因骨折愈合后膝关节屈曲小于90°需要行松解手术。结论手术治疗股骨远端骨折能够恢复解剖结构,从而最大限度地恢复肢体的功能。     

Microsurgical anatomy of the veins of the posterior fossa

The microsurgical anatomy of the veins of the posterior fossa was defined in 25 cadavers. These veins are divided into four groups: superficial, deep, brain-stem, and bridging veins. The superficial veins are divided on the basis of which of the three cortical surfaces they drain: the tentorial surface, which faces the tentorium and is exposed in a supracerebellar approach, is drained by the superior hemispheric and vermian veins; the suboccipital surface, which is below and between the lateral and sigmoid sinuses and is exposed in a wide suboccipital craniectomy, is drained by the inferior hemispheric and inferior vermian veins; and the petrosal surface, which faces forward toward the posterior surface of the petrous bone and is retracted to expose the cerebellopontine angle, is drained by the anterior hemispheric veins. The deep veins course in the three fissures between the cerebellum and the brain stem, and on the three cerebellar peduncles. The major deep veins in the fissures between the cerebellum and brain stem are the veins of the cerebellomesencephalic, cerebellomedullary, and cerebellopontine fissures, and those on the cerebellar peduncles are the veins of the superior, middle, and inferior cerebellar peduncles. The veins of the brain stem are named on the basis of whether they drain the midbrain, pons, or medulla. The veins of the posterior fossa terminate as bridging veins, which collect into three groups: a galenic group which drains into the vein of Galen; a petrosal group which drains into the petrosal sinuses; and a tentorial group which drains into the tentorial sinuses near the torcula.     

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.     

肝脏尾状叶肿瘤手术途径探讨

肝脏尾状叶肿瘤中最常见的是原发性肝癌和转移癌。其次,肝门胆管癌可通过尾状叶的胆管引流或直接浸润而侵犯肝尾状叶。迄今,手术切除仍是有效治疗肝尾状叶恶性肿瘤的唯一手段。由于尾状叶位置深、手术显露困难,且毗邻下腔静脉、肝静脉、门静脉等重要血管一直是肝脏外科手术的禁     

国人下腰椎前方血管解剖结构特点和入路分型

目的研究国人下腰椎前方血管与椎间隙之间的解剖特点,并进行解剖结构分型,为下腰椎前路椎间融合手术入路,尤其是腹腔镜下手术入路的选择提供解剖学依据。方法随机抽取94例国人腰椎MRI片,观察腰3-4、腰4-5,腰5-骶1椎间隙横断面前方的大血管解剖结构,判断腹主动脉的分叉位置和左髂总静脉与下腔静脉汇合位置,并进行解剖结构分型。结果根据腹主动脉分叉、左髂总静脉与下腔静脉汇合点与腰。椎间隙的上边缘之间的关系,确定4种类型。21例(22.3％)被归为A类(低分叉／低汇合),34例(36．2％)被归为B类(高分叉／高汇合),38例(40．4％)被归为C类(高分叉／低汇合),1例(1．1％)被归为D类(低分叉／高汇合)。在腰5-骶1间隙腹主动脉均已分叉,左髂总静脉均未汇合。男女之间无显著性差异。结论下腰椎前方血管解剖位置具有多变性,以腰4-5椎间隙为著,使腹腔镜下手术入路变的复杂。术前常规腰椎。MRI图像能用来进行血管解剖位置的分类,并设计最佳的手术入路。