Possibility of Middle Meningeal Artery-to-Petrous Internal Carotid Artery Bypass: An Anatomic Study

The possibility of creating a middle meningeal artery (MMA)-to-petrous internal carotid artery (ICA) bypass was investigated in six cadavers (bilaterally). Such a procedure could be used to treat patients with high cervical vascular lesions and those with tumors of the infratemporal fossa invading the high cervical ICA. After a frontotemporal craniotomy, the foramen spinosum and foramen ovale were exposed extradurally. Immediately posterior to the foramen ovale and medial to the foramen spinosum, the petrous portion of the ICA was exposed with a diamond-tipped drill. The MMA was lifted from its groove, and a sufficient length was transected to perform a bypass with the petrous ICA medially. The mean width of the MMA at the site of anastomosis was 2.3 +/- 0.35 mm. The mean length of MMA from the foramen spinosum to the site of the anastomosis was 9.6 +/- 1.7 mm. Based on these measurements, width and length of MMA appear to be sufficient for a bypass with petrous ICA.     

Radial artery graft for bypass of the maxillary to proximal middle cerebral artery: an anatomic and technical study

OBJECTIVE: In this study, we aimed to investigate the use of a radial artery graft for bypass of the maxillary artery (MA) to the proximal middle cerebral artery (MCA) as an alternative to superficial temporal artery-to-MCA anastomosis or extracranial carotid-to-MCA bypass using long grafts. METHODS: Five adult cadavers were used bilaterally. After a frontotemporal craniotomy and a zygomatic arch osteotomy, the MA was found easily 1 to 2 cm inferior to the infratemporal crest. A hole was created with a 4-mm-tip drill in the sphenoid bone 2 to 3 mm lateral to the foramen rotundum extradurally, and the dura over the hole was opened. After the carotid and sylvian cisterns had been opened, the M2 segment of the MCA was exposed. The graft was passed through the hole to reach the M2 segment. Then, the MA was freed from the surrounding tissue and was transected before the infraorbital artery branch. The radial artery graft was anastomosed end-to-end to the MA proximally and end-to-side to the M2 segment of the MCA distally. RESULTS: The mean thickness of the MA before the infraorbital artery branch was 2.6 +/- 0.3 mm. The mean thickness of the largest trunk of the MCA was 2.3 +/- 0.3 mm. The average length of the graft was 36 +/- 5.5 mm. CONCLUSION: MA-to-MCA bypass is as feasible as proximal MCA revascularization using long vein grafts. The thickness of the MA provides sufficient flow; the length of the graft is short, and it has a straight course. MA-to-proximal MCA bypass may be an alternative to superficial temporal artery-to-MCA as well as extracranial carotid-to-MCA bypasses.     

Distal Superficial Temporal Artery to Proximal Posterior Cerebral Artery Bypass by Posterior Oblique Transzygomatic Subtemporal Approach

This article investigates the possibility for the distal superficial temporal artery (STA) to proximal posterior cerebral artery (PCA) direct bypass by subtemporal oblique posterior transzygomatic approach. Five adult cadaveric specimens were dissected. Cadeveric dissection protocol was approved by the Research Ethics Committee. A preauricular vertical skin incision was made, the trunk of STA was identified, and bifurcation, frontal, and parietal branches of the STA were followed distally. Posterior zygomatic arch osteotomy and microcraniotomy were then performed, and the dura was opened. The temporal lobe was retracted, interpeduncular and ambient cisterns were opened, and the P2 segment of the PCA was exposed. Parietal branch of STA and P2 segment of the PCA was anastomosed. The average length of the transected STA from the bifurcation and the zygomatic arch were 47.3 ± 2.1 mm and 71.4 ± 2.3 mm, respectively. The mean calibers of the parietal and frontal branch of the STA at this distance were 1.6 ± 0.1 and 1.4 ± 0.2, respectively. The mean diameter of the P2 was 2.1 ± 0.2 mm. Because of the calibers of the parietal branch of the STA and proximal PCA are over 1.5 mm and 2.0 mm, respectively, this direct end-to-side bypass technique may be a reasonable alternative in suitable cases.     

Proximal STA to proximal PCA bypass using a radial artery graft by posterior oblique transzygomatic subtemporal approach

The aim of the present study was to investigate the use of a radial artery graft (RAG) for bypass of the proximal superficial temporal artery (STA) to proximal posterior cerebral artery (PCA) by posterior oblique transzygomatic subtemporal approach as an alternative to the external carotid artery (ECA) to PCA anastomosis. We conducted an anatomical and technical study at a university hospital. Five adult cadaveric specimens were dissected. A preauricular vertical skin incision was used. The trunk of STA was identified. A 30° oblique posterior zygomatic arch osteotomy and microcraniotomy was performed. The dura of the middle cranial fossa was then opened. The temporal lobe was retracted, the interpeduncular and ambient cisterns were opened, and the P2 segment of the PCA was exposed. The proximal side of the RAG was anastomosed with the proximal STA and the distal side was anastomosed with the P2 segment. The mean caliber of the proximal STA was 2.25 ± 0.35 mm. The mean diameter of the P₂ was 2.2 ± 0.2 mm. The average length of the RAG was 56 ± 3.2 mm. The mean caliber of the proximal and the distal sides of the graft was 2.5 ± 0.25 mm and 2.3 ± 0.15 mm, respectively. Because the proximal STA to proximal PCA bypass uses a short RAG and their calibers are over 2 mm, this bypass technique can provide a sufficient blood flow and may be a reasonable alternative over ECA to PCA bypass using long grafts. This study was presented as a research poster at the American Academy of Otolaryngology Head and Neck Surgery Foundation Annual Meeting on September 16–19, 2007 in Washington DC, USA.     

An anatomic study for a modified technique for bypass of the external carotid artery to the proximal middle cerebral artery

We aimed to evaluate whether bypass of the external carotid artery (ECA) to the middle cerebral artery (MCA) can be established by a short saphenous vein graft in order to increase the anastomosis patency. The method was performed to ten adult cadaver sides. We described a modified technique for bypass of the ECA to the M2 segment of MCA. The diameters of the vessels and graft length were measured by using an electronic micrometer. The mean diameter of the superior, middle, and inferior trunks of the MCA with trifurcation were 1.7 +/- 0.15, 2.2 +/- 0.25, and 2.0 +/- 0.2 mm, respectively, whereas the mean diameter of the superior and inferior trunks of the MCA with bifurcation were 2.1 +/- 0.2 and 2.3 +/- 0.3 mm, respectively. The mean diameter of the ECA was 3.75 +/- 0.4 mm. The mean length of the saphenous vein graft was 71.5 +/- 3.9 mm. The high-flow ECA to proximal MCA bypass using a short venous graft can supply enough blood flow to establish cerebral revascularization with a straighter route.     

面神经-舌下神经吻合术面神经干的显微解剖研究

目的观测面神经干的显微解剖,为面神经-舌下神经吻合术提供解剖学资料。方法解剖9例18侧福尔马林固定成人尸头,分别利用二腹肌后腹作为标志,在肌肉内侧寻找面神经干;在腮腺上作切口分离,寻找面神经干;以茎突作为标志追踪至颈乳孔,于茎乳孔处寻找面神经干的3种不同方法暴露面神经干。观测面神经干长度、深度、直径、分支及与周围结构的关系。结果面神经均由茎乳孔出颅。茎乳孔处面神经干直径为2.57±0.60mm,距皮肤的最小距离为22.62±2.88mm,面神经干长度为15.71±1.97mm,面神经干分叉至乳突尖的距离为18.20±4.41mm,分叉至下颌角的距离为39.91±8.38mm。乳突尖端至茎乳孔的距离为17.91±2.68mm,面神经干分叉前的主要分支有耳后神经、二腹肌神经和茎突舌骨肌神经。结论以茎突作为标志追踪至颈乳孔,在茎乳孔处寻找面神经干的方法安全可靠,面神经-部分舌下神经吻合是可行的。     

Anatomical study of the orbitozygomatic transsellar-transcavernous-transclinoidal approach to the basilar artery bifurcation

OBJECT: An anatomical study in which measurements were obtained was undertaken to demonstrate that the orbitozygomatic transcavernous-transclinoidal approach provides excellent exposure of the trunk of the basilar artery (BA) and its bifurcation. METHODS: Bilateral stepwise dissections were performed on 10 fixed cadaver heads with the aid of x 3 to x 40 magnifications. A frontotemporal craniotomy was made, followed by an orbitozygomatic osteotomy. After the dura mater had been opened, the sylvian fissure was widely separated. The anteromedial triangle of the cavernous sinus was opened to mobilize the internal carotid artery medially. The sella turcica and the dorsum sellae were exposed. The posterior clinoid process and the dorsum sellae were drilled to expose a length of BA that included its bifurcation. Measurements were obtained following the frontotemporal craniotomy, orbitozygomatic osteotomy, and drilling of the posterior clinoid process to quantify the exposures provided by these procedures. Excellent exposure of the trunk of the BA and its bifurcation was achieved. The structures in the interpeduncular cistern and the prepontine cistern were also exposed. There was an average gain of a 13.4-mm-long segment of the BA, which in some surgeries can be invaluable. The angle of exposure that was achieved with the BA bifurcation located at the apex increased markedly. Moreover, this method widened the oculomotor nerve-carotid artery corridor for easier access to the BA bifurcation region. CONCLUSIONS: This approach combines the advantages granted by most conventional approaches to aneurysms of the BA bifurcation. The approach is suitable for aneurysms situated at a high, normal, or low position on the BA bifurcation. It exposes a sufficient length of the BA trunk to place a temporary clip.     

Double aneurysms at distal basilar artery: report of nine cases

OBJECTIVE: Double aneurysms at the basilar bifurcation and the basilar artery-superior cerebellar artery (BA-SCA) junction have not been well investigated previously. We analyzed nine patients with double basilar aneurysms to evaluate their radiological characteristics and suitable treatment. METHODS: Between 1978 and 1999, the incidence of double aneurysms was 5.3% in our 169 consecutive surgical cases of distal BA aneurysms. Seven (77.8%) of the nine patients with double aneurysms had associated aneurysms in the anterior circulation. Open surgery was performed in eight patients and coil embolization in one. The patients' radiological findings, choice of treatment, and surgical results were analyzed retrospectively. RESULTS: The size of the basilar bifurcation aneurysms ranged from 2 to 8 mm (mean, 4.4+/-2.0 mm), and the size of the BA-SCA aneurysms ranged from 2 to 12 mm (mean, 5.6+/-3.6 mm). Diagnosis of double basilar aneurysms was difficult when the basilar trunk had twisted or when size differences between the two aneurysms were apparent. The angle between the posterior cerebral artery and SCA appeared to be wider on the same side as the BA-SCA aneurysms (101+/-42 degrees) than on the opposite side (26+/-24 degrees). The P1 segment of the posterior cerebral artery originated in an upright direction from the basilar bifurcation between the two basilar aneurysms in seven patients. The pterional approach was used in eight patients; 14 basilar aneurysms were successfully clipped and 2 were wrapped. Nonstraight clips with short blades were used frequently. Coil embolization of double aneurysms was required twice in one patient because the initial angiogram was misinterpreted as a single aneurysm and its bleb. CONCLUSION: Measurement of the posterior cerebral artery-SCA angle is a simple method to estimate the presence of BA-SCA aneurysms and to differentiate double aneurysms from a bilocular aneurysm at the basilar bifurcation. The pterional approach is suitable for clipping double basilar aneurysms because anterior circulation aneurysms often coexist, and the upstanding P1 segment is an obstacle in the subtemporal approach to the basilar bifurcation aneurysm. Nonstraight clips with short blades are convenient to avoid conflicting clips in the narrow surgical space.     

Proximal superficial temporal artery to proximal middle cerebral artery bypass using a radial artery graft: an anatomic approach

We present the use of radial artery graft for bypass of the proximal superficial temporal artery to the proximal middle cerebral artery. Six adult cadaver sites were used bilaterally. After apterional incision, 2×2-cm minicraniectomy was performed which began 2 cm behind the zygomatic process of the frontal bone. The superficial temporal artery was transsected before exposing the zygomatico-orbital artery branch. The proximal side of the radial artery graft was anastomosed end-to-end to the proximal superficial temporal artery and the distal side end-to-side to the proximal middle cerebral artery. The mean calibers of the proximal superficial temporal artery and largest trunk of the middle cerebral artery were 2.25±0.35 mm and 2.3±0.3 mm, respectively. The average graft length was 85±5.5 mm. We conclude that such bypasses are simpler than proximal middle cerebral artery revascularization using long vein grafts. This method proves that the caliber of the proximal superficial temporal artery is more suited to providing sufficient flow than the distal superficial temporal artery, and the graft is short. Such bypasses to the middle cerebral artery may be an alternative to those from the distal superficial temporal artery or extracranial carotid artery.     

The inferior epigastric arteries as coronary bypass conduits. Size, preoperative duplex scan assessment of suitability, and early clinical experience.

We are currently evaluating the inferior epigastric artery as an alternative arterial conduit for coronary bypass grafting. Fifty-seven inferior epigastric arteries were harvested from 47 adults. There were no differences in size between the right and left inferior epigastric arteries. Diameter was 2.5 to 3.5 mm proximally and 2 to 3 mm distally. Usable length was 6 to 16 cm (mean 11.2 +/- 0.25 cm). Grade I/IV atherosclerosis was found in one patient (2.1%). Duplex scanning was used for preoperative evaluation of the inferior epigastric arteries in 51 patients. In 21 patients the arteries were not harvested, in part because of duplex scan findings of small caliber or early bifurcation. In 30 patients the duplex findings could be compared with the surgical findings. The average length at operation was twice the length detected on duplex scan (11.2 cm versus 5.8 cm, p less than 0.001). There was a good correlation between diameter on duplex scan and that measured at operation (2.56 +/- 0.05 versus 2.62 +/- 0.07, p = not significant). Between December 1989 and May 1991, 38 patients (29 to 74 years, mean 56 years) received 42 inferior epigastric artery grafts. Proximal anastomoses were to the aorta in 17, to the vein graft hood in 20, or onto an internal mammary artery graft in 5. Distal anastomoses were to the left anterior descending artery in 2, the diagonal branch in 27, the marginal branch in 9, or the right coronary artery in 4. There were no early deaths. Complications included perioperative myocardial infarction in 1, deep sternal wound infection in 2, superficial infection at the harvest site of the inferior epigastric artery in 5, and reexploration for bleeding in 2. Because of its size and the low incidence of atherosclerosis, the inferior epigastric artery may evolve as an alternative arterial conduit for coronary bypass. Duplex scanning is a valuable noninvasive tool for preoperative evaluation of the artery's suitability. Long-term studies of patency of the inferior epigastric artery as a coronary bypass conduit are needed.     

颈横血管肩胛冈支骨瓣移位修复下颌骨缺损的应用解剖

目的为下颌骨缺损提供带血管蒂骨瓣移位修复术的应用解剖学基础。方法在１５具（３０侧）灌注红色乳胶的成人尸体标本上,观测颈横血管及其肩胛冈支的走行、分支及分布。结果颈横动脉全程分为：颈段,长（４．７±０．１）ｃｍ,起始外径（４．０±０．１）ｍｍ;背段,长（５．８８±０．６３）ｃｍ,起始外径（３．３０±０．３５）ｍｍ。颈横动脉肩胛冈支８６．７％起于颈横动脉浅支,１３．３％起自颈横动脉,干长（４．９７±１．６８）ｃｍ,起始外径（２．０８±０．２７）ｍｍ。肩胛冈支恒定地向肩胛冈发出４～８支骨膜支营养肩胛冈。结论颈横血管肩胛冈支是肩胛冈区的主要血供来源之一,以其为蒂的肩胛冈骨瓣可以颈横血管背段起始处为旋转点向下颌区移位,血管蒂平均长约１０．８５ｃｍ,可为下颌骨缺损修复提供一种新的术式。     

About the Suboccipital Part of the Vertebral Artery and the Neighboring Bone-Joint and Nerve Relationships

Length measurements, nerve-vessel relationships, and vessel relationships to articulations and the dura mater were examined in 65 head and neck halves. The paramedian distance of the vertebral artery (midpoint) is a mean of 15.8 mm on the right, and a mean of 17.3 mm on the left, in the area of the intervertebral symphysis C2-C3 at the transverse foramen of the axis the artery has a paramedian mean distance of 17 mm. After the exit of the artery from the axis four types of loop formations of the axoatlantal part and their occurrences are described. Also, the atlantal part of the artery was studied: the overlapping of the posterior arch of the atlas was 5.14 (0 to 13) mm. The length of the axoatlantal part of the vertebral artery was a mean of 39 mm, and the length of the atlantal part was a mean of 44 mm. Besides the measurements of the outer diameter of the artery, the branches and anastomoses of the V₃ segment, nerve-vessel and nerve-joint relationships of the artery, and some veins of the craniocervical junction are described. All findings are discussed in relation to their clinical significance.     

About the suboccipital part of the vertebral artery and the neighboring bone-joint and nerve relationships

Length measurements, nerve-vessel relationships, and vessel relationships to articulations and the dura mater were examined in 65 head and neck halves. The paramedian distance of the vertebral artery (midpoint) is a mean of 15.8 mm on the right, and a mean of 17.3 mm on the left, in the area of the intervertebral symphysis C2-C3 at the transverse foramen of the axis the artery has a paramedian mean distance of 17 mm. After the exit of the artery from the axis four types of loop formations of the axoatlantal part and their occurrences are described. Also, the atlantal part of the artery was studied: the overlapping of the posterior arch of the atlas was 5.14 (0 to 13) mm. The length of the axoatlantal part of the vertebral artery was a mean of 39 mm, and the length of the atlantal part was a mean of 44 mm. Besides the measurements of the outer diameter of the artery, the branches and anastomoses of the V(3) segment, nerve-vessel and nerve-joint relationships of the artery, and some veins of the craniocervical junction are described. All findings are discussed in relation to their clinical significance.     

The perforating branches of the middle cerebral artery. A microanatomical study

The perforating branches (PFB's) of the middle cerebral artery (MCA) were studied in 34 unfixed brain hemispheres which were injected with a polyester resin and dissected under the operating microscope. Five hundred and eight vessels were identified and their site of origin, branching pattern, outer diameter (OD), and length recorded. Four hundred and two PFB's (79%) originated from the main trunk of the MCA before its division; the remaining 106 vessels (21%) had their origin from branches of the MCA as follows: superior trunk, 43 vessels (8.5%); inferior trunk, 30 vessels (6%); middle trunk, four vessels (0.8%); early temporal branch, 27 vessels (5.3%); and early frontal branch, two vessels (0.4%). The number of PFB's in each hemisphere varied from five to 29 (mean 14.9 +/- 0.7 vessels). The great majority of PFB's (96%) originated along the proximal 17 mm of the MCA. The PFB's arising in the first 10 mm had a mean OD of 0.35 +/- 0.01 mm and a mean length of 9.25 +/- 0.19 mm, and those arising from the second 10 mm had a mean OD of 0.47 +/- 0.02 mm and a mean length of 16.67 +/- 1.4 mm. A clear distinction between a medial and lateral group of PFB's was present in only 14 hemispheres (41%). In nine hemispheres (26%), perforating vessels from the anterior cerebral artery (A1 segment) and from the recurrent artery of Heubner replaced the medial group of PFB's of the MCA. In one case this group originated in an accessory MCA. In three hemispheres (9%) a small anastomosis (OD 0.2 mm) was seen between a PFB of the recurrent artery of Heubner and one of the MCA. From a total of 508 PFB's, 255 vessels (50%) originated as single vessels, while 253 vessels (50%) originated as branches of common stems. The OD of the single vessels ranged from 0.1 mm to 1.1 mm (mean 0.39 +/- 0.02 mm), and the length from 3 to 20 mm (mean 10.8 +/- 0.2 mm). The common stems ranged in OD from 0.6 to 1.8 mm (mean 0.87 +/- 0.04 mm), and in length from 1 to 15 mm (mean 4.1 +/- 0.4 mm). The clinical application of these anatomical data to the management of aneurysms and arteriovenous malformations of the MCA, and in the field of interventional neuroradiology is described. The most frequent pathological entities involving the perforating vessels are also discussed.     

Retrograde flow in the internal mammary artery

Thirty-two patients undergoing coronary artery bypass grafting were studied to evaluate retrograde flow in the internal mammary artery (IMA). The left IMA pedicle was prepared in routine fashion from the level of the first rib superiorly to just distal to the IMA bifurcation. Following cannulation for cardiopulmonary bypass but before institution of extracorporeal circulation, the IMA was divided 5 mm proximal to its bifurcation and allowed to bleed freely. The flow from each end was then measured by allowing the segment to bleed for 30 seconds. The mean antegrade flow was 73 +/- 34 ml/min, and the retrograde flow was 25 +/- 17.2 ml/min. The difference between the flows was significant (p less than 0.05). Based on these data we do not recommend the retrograde IMA technique as a primary form of revascularization of the myocardium. In selected circumstances it may be used if adequate retrograde flow is demonstrated before constructing the anastomosis.     

Simulation study on bypass and therapeutic occlusion in the posterior circulation

Summary A hydraulic vascular model of the vertebrobasilar artery with an autoregulatory mechanism was constructed. The haemodynamic effect of superficial temporal artery (STA)-posterior cerebral artery (PCA) bypass was investigated in cases of bilateral vertebral artery (VA) occlusion and basilar artery (BA) occlusion. Assuming therapeutic BA occlusion for basilar bifurcation aneurysms, the flow volume through the P 1 segment of the PCA was determined in relation to diameters of the posterior communicating artery (PCom).The bypass increases both flow volume and intraluminal pressure in the pressure range below 60 mm Hg, while it increases only pressure in the autoregulatory range above 60 mm Hg. Its haemodynamic effect is more marked in BA occlusion than in VA occlusion. The averaged values of the increase in flow volume are 29.0±4.3% (mean±SD) and 16.5+1.0%, respectively. The total flow volume increase of the vertebrobasilar system is usually lower than the flow volume measured at the bypassed STA. The difference between the two is equal to the simultaneous decrease in flow volume through the PComs. Flow volume through the P1 segment can be expressed as a function of the PComs diameter ratio squared.A hydraulic simulation study will be useful for speculating on the haemodynamic effects of these operative procedures.     

A vertebral artery tortuous course below the posterior arch of the atlas (without passing through the transverse foramen). Anatomical report and clinical significance

A vertebral artery (VA) coursing below the posterior arch of the atlas (C1) without passing through the transverse foramen of C1, combined with a tortuous course within the spinal canal has rarely been reported in the literature. This article describes a case encountered during an anatomical study of the far-lateral approach, and reviews its embryonic development and clinical significance. The suboccipital triangle was filled with numerous venous plexures. After exiting from the transverse foramen of C2, instead of passing upwards through the transverse foramen of C1, the VA turned directly medially towards the spinal canal. At the spinal canal, it first formed an angle downwards, then turned upwards, piercing and entering the lateral part of the dura at C1 level. The diameter of this VA seemed to be within its normal limits. The course of the contralateral (right) VA was normal but with a small caliber and mainly supplied the posterior inferior cerebellar artery (PICA); after PICA, it became much thinner and dysplastic, the basilar artery was mainly supplied by the left VA. The bilateral posterior communicating arteries were large in diameter but there was dysplasia of the P1 segment of the posterior cerebral arteries bilaterally. Marked tortuosity of the bilateral intracavernous internal carotid artery (ICA) was also found. We did not find any osseous abnormality in the occipito-axial region or of C1-C2 joint. An abnormal course of the VA should be kept in mind during exposure of the craniocervical junction, especially in the variety of lateral approaches; due to compression of the nerve roots or the spinal cord, this abnormal course of the VA could give rise to clinical symptoms, which could be resolved by microvascular decompression technique.     

Fractal or biologically variable delivery of cardioplegic solution prevents diastolic dysfunction after cardiopulmonary bypass.

OBJECTIVE: To determine whether myocardial protection is improved by restoring physiologic variability to the cardioplegia pressure signal during cardiopulmonary bypass, we compared cardiac function in pigs in the first hour after either conventional cold-blood cardioplegia (group CC) or computer-controlled biologically variable pulsatile cardioplegia (group BVC). METHODS: Invasive monitors and sonomicrometry crystals were placed, and cardiopulmonary bypass was initiated. The aorta was crossclamped, and cold blood cardioplegic solution was infused intermittently through the aortic root with either conventional cardioplegia (n = 8) or biologically variable pulsatile cardioplegia (n = 8; mean pressure, 75 mm Hg for 85 minutes). The crossclamp was released, cardiac function was restored, and separation from cardiopulmonary bypass was completed. With stable temperature and arterial blood gases, hemodynamics and systolic and diastolic indices were compared at 15, 30, and 60 minutes after cardiopulmonary bypass. RESULTS: Diastolic stiffness doubled from 0.027 +/- 0.016 mm Hg/mm (mean +/- SD) at baseline to 0.055 +/- 0.036 mm Hg/mm (P =.003) at 1 hour after bypass in group CC, associated with increased left ventricular end-diastolic pressure from 9 +/- 2 to 11 +/- 2 mm Hg (P =.001), mean pulmonary artery pressure from 14 +/- 2 to 20 +/- 3 mm Hg (P =.003), and serum lactate levels from 2.0 +/- 0.5 to 5.6 +/- 2.3 mmol/L (P =.008). Systolic function was not affected. In group BVC diastolic stiffness, left ventricular end-diastolic pressure, and pulmonary artery pressure values were not different from control values at any time after bypass, and serum lactate levels were significantly less than with conventional cold blood cardioplegia. Peak pressure variability with biologically variable pulsatile cardioplegia fit a power-law equation (exponent = -3.0; R(2) = 0.97), indicating fractal behavior. CONCLUSION: Diastolic cardiac function is better preserved after cardiopulmonary bypass with biologically variable pulsatile cardioplegia and fractal perfusion. This may be attributed to enhanced microcirculatory perfusion with improved myocardial protection. A model supporting these results is presented.     

Morphometric Analysis of the Middle Meningeal Artery Organization in Humans—Embryological Considerations

The middle meningeal artery (MMA) is the largest branch of the internal maxillary artery supplying the meninges. The complex sequence of MMA development gives many opportunities for variant anatomy. Additionally, the variations in the origin of the MMA are of clinical importance when dealing with fractures of the base of the skull, epidural hematomas, and bypass procedures. Therefore, various anastomosis and aberrant origins of the MMA have been documented in literature. However, there are no reports about some morphometric aspects of this important arterial segment. Thus, in this study, we decided to investigate the anatomical organization of the MMA through the bony groove measurements from human skulls (n = 50 subjects). Six measurements were performed bilaterally: angle of the main trunk, length of the main trunk, angle between the frontal and parietal branches, length of the frontal branch, length of the parietal branch, and length of the bony tunnel formed by the frontal branch. We showed that the anatomical organization of the MMA is bilaterally similar, except for the length of the parietal branch (p = 0.009). Moreover, our results provide baseline normal values for future studies aimed at further elucidating the functional and morphological pattern of the MMA.     

Lingual and facial arteries arising from the external carotid artery in a common trunk

The present study describes analytically a rare case in which lingual and facial arteries arise together from an external carotid artery in a common trunk. Thirty anatomic dissections were performed on 15 cadavers in the macroscopic laboratory in the Department of Anatomy of the Medical School of National and Kapodistrian University of Athens. One common trunk from which originated lingual and facial arteries was found. The frequency of this morphology is measured at 6 per cent. The length of the common trunk is measured at 7.3 mm between its origin and its diversion at the facial artery and lingual artery, its diameter at 2.8 mm, its distance from carotid bifurcation at 7.9 mm, and from the superior thyroid artery at 3.3 mm. At the left side of the neck region, facial and lingual arteries arose separately. The anatomic variations of the branching pattern of the external carotid artery and the micrometric values of the vessels are especially important as a result of the numerous operations performed in the neck region that implicate various specialties such as general surgery, head and neck surgery, plastic surgery, and maxillofacial surgery.