RESUMEN

OBJECTIVE: The cerebral and spinal venous systems have similar functions but unique anatomical and physiological properties. CSF occupies space in the cranial and spinal vaults, is continuously produced, and has many roles, including maintaining a favorable environment for CNS structures. The influence of the cerebrospinal venous system on CSF dynamics has been theorized since the 1940s. Newer studies suggest venous outflow pattern alterations in response to changes in body position. However, the relationship of postural cerebrospinal venous outflow shifts with and their influence on CSF homeostasis is not well understood. METHODS: The authors searched the published literature related to the anatomy and function of vertebral venous plexus (VVP), CSF, and positional cerebral venous flow characteristics. A comprehensive collection of literature was compiled and reviewed, and the relationship between cerebrospinal and venous system changes and alterations in body positions, with an emphasis on the craniocervical system, is discussed. RESULTS: The VVP is a network of valveless veins extending from the sacrum to the cranium that are interconnected with the cranial dural sinuses. The internal VVP occupies space within the extradural spinal canal and functions to return spinal venous blood to the heart, but it has additional properties, including the capability of bidirectional venous flow, an intraspinal dilatory capacity, and a role in cerebral venous outflow. When one rises to the upright position, CSF shifts toward the spinal canal and force vectors change, leading to reduced intracranial CSF pressure; simultaneously, cerebral venous outflow shifts from the jugular vein to the VVP outflow pathway. The venous outflow shift mechanism and its purpose are poorly understood. The authors review the known physiology of the system, identify gaps in knowledge to direct future research, and propose an interpretation of these data, concluding that position-dependent CSF and cerebrospinal venous shifts are part of a complementary positional craniospinal pressure regulation system that must be kept in balance for optimal CNS function. CONCLUSIONS: Current knowledge of the cerebrospinal venous anatomy, dynamic flow characteristics in response to gravity, and the venous system's influence on CSF suggests that the VVP plays a role in influencing CSF pressure, and the authors hypothesize that it plays a role in supporting intracranial pressure in the upright body posture. Further research is needed to better characterize the functional relationship of the VVP to CSF dynamics as well as identify potentially related disease states.

RESUMEN

Dural arteriovenous fistulas (DAVFs) within the falx cerebri are infrequently documented and may be linked with the falcine sinus/venous plexus. The falcine sinus/venous plexus, often regarded as a normal venous structure, can exhibit pathological characteristics, differing from the persistent fetal falcine sinus. A retrospective analysis was conducted at a single center to identify all cases of DAVFs within the falx cerebri spanning from 2002 to 2022. Demographic data, fistula features, treatment modalities, clinical outcomes, and fistula closure were collected and analyzed. Additionally, relevant literature on DAVFs in this location was reviewed. Ten cases were identified at our center, supplemented by 13 cases reported in the literature. In our cohort, patients had an average age of 49.4 ± 8.1 years, with a male predominance of 90%. Trans-arterial embolization (TAE) alone achieved immediate complete occlusion in eight cases, while conservative treatment was pursued in two cases. No treatment-related complications or fistula recurrences were observed. In the literature, seven patients underwent direct surgery, three underwent TAE, and one underwent both direct surgery and radiosurgery for complete fistula closure. No instances of fistula recurrence or treatment complications were reported. Dural arteriovenous fistulas within the falx cerebri are rare, with limited literature available. They typically present as aggressive lesions. Treatment options include direct surgery or TAE. However, due to a lack of long-term DSA follow-up, the cure and recurrence rates are unknown for endovasdcular therapy. Further investigation is warranted to elucidate the involvement of the falcine sinus/venous plexus in falx cerebri DAVFs.

Asunto(s)

Asunto(s)

RESUMEN

Superficial siderosis (SS) of the central nervous system is a rare disorder that is caused by chronic or recurrent hemorrhage in the subarachnoid space via a dural defect at the spinal level. The most common clinical features of SS include slow-progressive sensorineural deafness, cerebellar symptoms, and pyramidal tract signs. Considering that SS can present with broad clinical manifestations, for precise diagnosis, this disease must be understood. Anti-Ro/SSA antibodies are commonly detected in patients with Sjögren's syndrome and are utilized as markers for autoimmune diseases. In this report, we present a unique pathological condition in which SS coincided with a positive anti-Ro/SSA antibody test result. During the diagnosis of gait disturbance, an elevation in anti-Ro/SSA antibody was detected, and steroid pulse therapy was initiated as the initial treatment for autoimmune diseases. Head magnetic resonance imaging (MRI) revealed extensive hypointensity as a dark band that surrounded the intracranial basal structures and cerebellar hemispheres. Spinal MRI indicated ventral longitudinal intraspinal fluid collection extending from C7 to T5 as well as a defect in the ventral T2-3 dura mater. Intraoperative visualization revealed that the intradural venous plexus was the source of bleeding that caused the SS. To our knowledge, this report is the first to discuss the presence of anti-Ro/SSA antibodies in patients with SS. The role of anti-Ro/SSA antibodies in the pathophysiology of SS remains unclear; therefore, to confirm a possible association, further research and accumulation of cases are required.

RESUMEN

Objective: Hirayama disease is a rare cause of cervical myelopathy predominantly affecting young individuals. The disease is classically characterized by muscle atrophy in the distal upper limbs. While various etiopathogenesis such as dural sac dysplasia, nerve root dysplasia, structural abnormalities of the spinal ligament, and venous dysplasia have been proposed, this study explores the potential role of venous pathology and surgical management on the basis of it. Methodology: This is a prospective descriptive case series of nine cases. The diagnosis was made based on the Huashan diagnostic criteria which includes clinical manifestation, imaging, and electrophysiology. In cases where magnetic resonance imaging (MRI) failed to demonstrate engorged veins, a computed tomography (CT) venogram of the cervical spine was used as an imaging tool. All patients underwent cervical laminectomy and coagulation of the posterior epidural venous plexus with or without laminoplasty. All the patients were followed up regularly; clinical improvement and neck disability index were assessed. Results: All nine patients were male and exhibited classical clinical features, electrophysiological abnormalities, and MRI findings except, in one patient where a CT venogram helped in establishing the diagnosis as the MRI was inconclusive. Postoperatively, all patients had neurological improvement and stabilization of the disease. All patients who underwent CT venogram and cervical spine X-ray in neutral and dynamic position demonstrated no recurrence of engorged venous plexus or significant instability except one patient developing kyphosis. One patient experiencing symptoms in the other limb underwent a second surgery. Conclusion: This comprehensive case series strongly supports venous pathology as a potential etiology of Hirayama disease. Surgical management with laminectomy and venous coagulation with or without expansile laminoplasty has delivered consistent improvement in neurological outcomes and long-term disease stabilization without the restriction of movements and lesser complications. However, further research is warranted to elucidate the mechanism underlying cervical venous dilatation.

RESUMEN

BACKGROUND: Spontaneous intracranial hypotension (SIH) is a rare condition characterized by positional headache, for which contrast-enhanced magnetic resonance imaging (MRI) is the preferred diagnostic method. Although MRI reveals characteristic findings, head computed tomography (CT) is usually the first diagnostic step, but identifying features of SIH on CT is often difficult. This study was specifically designed to evaluate the utility of head CT in detecting upper cervical epidural venous engorgement as a sign of SIH. OBSERVATIONS: Of 24 patients with SIH diagnosed between March 2011 and May 2023, 10 did not undergo upper cervical CT. In the remaining 14 patients, engorgement of the upper cervical epidural venous plexus was observed. CT detection rates were consistent with MRI for spinal fluid accumulation or dural thickening. After treatment, in 92.9% of patients, the thickness of the epidural venous plexus decreased statistically significantly from 4.8 ± 1.3 mm to 3.6 ± 1.2 mm. LESSONS: This study suggests that upper cervical spine CT focused on epidural venous engorgement may be helpful in the initial diagnosis of SIH and may complement conventional MRI evaluation. Extending CT imaging to the upper cervical spine will improve the diagnostic accuracy of patients with positional headaches suspected to be SIH.

RESUMEN

Spinal cord injury is difficult to detect directly on postmortem computed tomography (PMCT) and it is usually diagnosed by indirect findings such as a hematoma in the spinal canal. However, we have encountered cases where the hematoma-like high-attenuation area in the cervical spinal canal was visible on PMCT, while no hematoma was observed at autopsy; we called it a "pseudo hematoma in the cervical spinal canal (pseudo-HCSC)." In this retrospective study, we performed statistical analysis to distinguish true from pseudo-HCSC. The cervical spinal canal was dissected in 35 autopsy cases with a hematoma-like high-attenuation area (CT values 60-100 Hounsfield Unit (HU)) in the spinal canal from the first to the fourth cervical vertebrae in axial slices of PMCT images. Of these 22 had a hematoma and 13 did not (pseudo-HCSC). The location and length of the hematoma-like high-attenuation and spinal cord areas were assessed on reconstructed PMCT images, true HCSC cases had longer the posterior hematoma-like area and shorter the spinal cord area in the midline of the spinal canal (P < 0.05). Furthermore, we found that true HCSC cases were more likely to have fractures and gases on PMCT while pseudo-HCSC cases were more likely to have significant facial congestion (P < 0.05). We suggest that pseudo-HCSC on PMCT is related to congestion of the internal vertebral venous plexus. This study raises awareness about the importance of distinguishing true HCSC from pseudo-HCSC in PMCT diagnosis, and it also presents methods for differentiation between these two groups.

Asunto(s)

RESUMEN

Atlas and axis instrumentation may be necessary in cases of several craniocervical junction pathologies. According to the Harms technique, C1-C2 polyaxial screws are inserted respectively in the C1 lateral masses and in C2 pedicles. C1 lateral mass screw insertion requires the careful subperiosteal dissection of the posterior elements of C1, the identification of the screw entry point by the downward distraction of C2 nerve root, and the cautious sparing of the overlying posterior external vertebral venous plexus (peVVP), whose bleeding, obstructing the surgical field, is sometimes barely controlled by hemostatic agents and swabbing. The authors describe in detail the anatomical aspects of an alternative surgical technique developed for the microsurgical transposition of the C1-C2 interposed external vertebral venous plexus in the case of Harms C1-C2 screw stabilization. The longitudinal median incision of the atlantoaxial membrane, followed by bilateral subperiosteal dissection and microsurgical section respectively at the inferior borders of the C1 laminae and at the superior borders of the C2 laminae, allows, as a "window opening," the symmetrical mediolateral transposition of the peVVP. This procedure provides a faster and cleaner anatomical exposition of the posterior surface of the C1 lateral mass and the C2 isthmus, preventing troublesome intraoperative venous bleeding that hinders C1 lateral mass screw insertion.

Asunto(s)

RESUMEN

Background Adaptive arterial remodeling caused by flow reduction from downstream stenosis has been demonstrated in animal studies. The authors sought to determine whether inward remodeling from downstream stenosis also occurs in humans and is detectable by ex vacuo expansion of the Rektorzik venous plexus (RVP) surrounding the petrous internal carotid artery. Methods and Results The authors analyzed 214 intracranial magnetic resonance imaging examinations that included contrast-enhanced vessel wall imaging. RVP symmetry was qualitatively assessed on vessel wall imaging. RVP thickness (RVPT) was measured on the thicker side if asymmetric or randomly assigned side if symmetric. Maximum stenosis (M1 or intracranial internal carotid artery) was measured. Posterior communicating artery and A1 diameters (>1.0 mm and 1.5 mm, respectively) defined adequate collateral outflow when proximal to the stenosis. Seventy-two patients had stenosis downstream from RVPT measurements. For those without adequate outflow (38 of 72), 95.0% with RVPT ≥1.0 mm had ≥50% stenosis compared with only 5.6% with RVPT <1.0 mm. For these 72 patients, higher RVPT (RVPT ≥1.0 mm versus <1.0 mm) and absent adequate outflow were associated with greater downstream stenosis (P<0.001) using multivariate regression. For patients with downstream stenosis without adequate outflow, asymmetric RVP thickening was associated with greater ipsilateral stenosis (P<0.001, all had ≥46% stenosis) when stenosis was unilateral and greater differences in stenosis between sides (P=0.005) when stenosis was bilateral. Conclusions Inward internal carotid artery remodeling measured by RVPT or RVP asymmetry occurs as downstream stenosis approaches 50%, unless flow is preserved through a sufficiently sized posterior communicating artery or A1, and may serve as a functional measure of substantial flow reduction from downstream stenosis.

Asunto(s)

RESUMEN

BACKGROUND: Nerve-sparing radical hysterectomy(NSRH)has the advantage of reducing postoperative complications and improving postoperative quality of life. The separation and protection of the pelvic plexus in NSRH is extremely important and challenging. METHODS: 24 female cadaveric hemipelves were dissected. Morphologic patterns and compositions of pelvic plexus as well as relationship of pelvic plexus to the surrounding structures were observed and documented. RESULTS: Two patterns of superior hypogastric plexus were observed, including fenestrated and cord-like shape. The origin of bilateral hypogastric nerves were inferiorly to upper margin of promontory about 1.6 ± 0.1 cm and parallel to the ureter in front of the sacrum. Pelvic splanchnic nerves(PSN)from the second sacral nerve, the third sacral nerve and the forth sacral nerve were observed combing with the hypogastric nerves within the lateral rectal ligament. The sacral sympathetic trunk can be identified anteriorly or medially to the anterior sacral foramen. We identified the boundaries of pelvic plexus as following: the upper margin is formed by the PSNs from the third sacral nerve, posterior margin by inferior rectal artery, and anteriorly by vesical venous plexus. The uterine branches from pelvic plexus were observed accompanying with uterine artery, while other branches were inferiorly to the artery. The PSNs were located beneath the deep uterine veins within the cardinal ligament. The upper margin of pelvic plexus was observed directly approach to urinary bladder within the vesico-vaginal ligament as a single trunk accompanying with ureter, between the middle and inferior vesical veins. CONCLUSIONS: Our study clarified the intricate arrangement, distribution and relationship of female pelvic plexus and the related structures to provide reference index for NSRH application. The innervation patterns of bladder and uterine were clarified, and by tracing these visceral branches of pelvic plexus, we suggest several new important land markers for NSRH.

Asunto(s)

RESUMEN

BACKGROUND: Percutaneous glycerol rhizotomy (PGR) is a common, effective, and relatively safe treatment for trigeminal neuralgia that is refractory to medical management. Anastomotic skull base venous anatomy should be considered when delivering percutaneous agents. OBSERVATIONS: The authors report an anastomotic connection, not previously described in the literature, between the bilateral pterygoid venous plexuses upon air injection during PGR with computed tomography (CT) guidance for trigeminal neuralgia. Pertinent microsurgical and skull base venous anatomy is reviewed. LESSONS: Anastomoses between the pterygoid venous plexuses present a potential passage for materials used during PGR to reach unintended contralateral neurovascular structures. The use of CT guidance may identify this anastomotic connection and decrease the likelihood of an aberrant flow of materials used during the PGR.

RESUMEN

BACKGROUND AND AIMS: Both anaesthesiologists and spine surgeons consider the intra-abdominal pressure (IAP) as an important peri-operative factor affected by patient positioning. We assessed the change in IAP caused by using a thoraco pelvic support (inflatable prone support, IPS) with the subject under general anesthesia. The IAP was measured before, during and immediately after surgery. METHODS: The Spine Intra-Abdominal Pressure study (SIAP trial) is a prospective, single-arm, monocenter, observational study looking at changes in IAP prior, during and after spine surgery. The objective is to assess the change in IAP, measured via an indwelling urinary catheter, using the inflatable prone support (IPS) device during prone positioning of patients in spinal surgery. RESULTS: Forty (40) subjects requiring elective lumbar spine surgery in prone position were enrolled after providing informed consent. The inflation of the IPS results in a significant decrease of IAP (from a median of 9.2 mmHg to 6.46 mmHg (p < 0.001)) in patients undergoing spine surgery in prone position. This decrease in IAP was maintained throughout the procedure despite the discontinuation of muscle relaxants. No serious adverse events or unexpected adverse events occurred. CONCLUSION: The use of the thoraco-pelvic support IPS device was able to significantly lower the IAP during spine surgery.

Asunto(s)

RESUMEN

BACKGROUND: The internal jugular vein (IJV) is the pre-eminent outflow of the dural venous sinuses (DVS) in the supine position, while the vertebral venous plexus (VVP) dominates venous outflow in the upright position. Emissary veins can also be an accessory pathway for this venous egress. To our knowledge, alternative dural venous sinus directly drainage via the diploic space has not been previously reported in the literature. METHODS: Ten fresh frozen adult cadavers underwent exposure of the basilar venous plexus. The entire plexus, still adhered to the underlying clivus, was removed with its underlying bone and submitted for histological examination following decalcification (Masson Trichrome, 5 µm slices). RESULTS: All specimens were found to have direct communication between the basilar venous plexus and underlying diploic space of the clivus i.e., no intermediate clival emissary vein. These were concentrated near the midline and were more numerous over the clivus near the junction of the occipital and sphenoid bones. The endothelium of the venous sinus was continuous at the opening into the diploic space and these openings ranged in size from 500 to 750 µm (mean 650 µm). CONCLUSIONS: An improved understanding of the cerebral venous drainage can assist clinicians and surgeons in recognizing normal, pathologic, and variant anatomy in this region. Based on our study, direct venous sinus (DVS) to diploic space drainage offers an additional pathway for venous egress from the intracranium. Therefore, removal of the dura over the clivus during various skull base procedures might be associated with increased venous bleeding from the basilar venous plexus on its deep surface where it interfaces with the clivus.

Asunto(s)

RESUMEN

BACKGROUND: Spontaneous uterine venous rupture combined with ovarian rupture in late pregnancy is extremely rare. It often has an insidious onset and atypical symptoms, develops rapidly, and is easily misdiagnosed. Wewould like to discuss and share this case of spontaneous uterine venous plexus combined with ovarian rupture in the third trimester of pregnancy with colleagues. CASE PRESENTATION: A pregnant woman, G1P0 at 33+4 weeks of gestation,was admitted to the hospital due to threatened preterm labour on March 3, 2022. After admission, she was treated with tocolytic inhibitors and foetal lung maturation agents. The patient's symptoms did not improve during the treatment. After many examinations, tests, discussions, a diagnosis, and a caesarean section, the patient was finally diagnosed with atypical pregnancy complicated by spontaneous uterine venous plexus and ovarian rupture. CONCLUSIONS: Spontaneous rupture of the uterine venous plexus combined with ovarian rupture in late pregnancy is an occult and easily misdiagnosed condition, and the consequences are serious. Clinical attention should be given to the disease and prevention attempted to avoid adverse pregnancy outcomes.

Asunto(s)

RESUMEN

Objective: The clinical grading system for varicoceles is subjective and dependent on clinician experience. Color Doppler ultrasound (US) has not been standardized in the diagnosis of varicoceles. We aimed to determine if US measurement of varicocele could be predictive of World Health Organization (WHO) varicocele grade. Methods: Men who presented for either scrotal pain or infertility to a tertiary men's health clinic underwent physical examination, and varicoceles were graded following WHO criteria (0=subclinical, 1, 2, 3). US was used to measure largest venous diameter in the pampiniform plexus bilaterally at rest and during Valsalva maneuver. Receiver operator characteristic curve analysis was used to determine if resting diameter, diameter during Valsalva, or change in diameter between at rest and during Valsalva provided the highest sensitivity and specificity for determining clinical grade. Threshold values for diameter were determined from these receiver operator characteristic curves. Results: A total of 102 men (50 with clinical varicocele and 52 with subclinical varicocele) were included. Diameter at rest was the best ultrasonographic discriminator between subclinical and clinical varicoceles (area under the curve [AUC]=0.67) with a diameter threshold of 3.0 mm (sensitivity 79%, specificity 42%). Diameter during Valsalva had the greatest AUC for determining clinical Grades 1 versus 2 (AUC=0.57) with diameter threshold of 5.7 mm (sensitivity 71%, specificity 33%). For differentiating between Grades 2 and 3, diameter at rest had the greatest AUC of 0.65 with a threshold of 3.6 mm (sensitivity 71%, specificity 58%). Conclusion: Our results corroborate other studies that have shown a weak correlation between US and clinical grading. The use of diameter during Valsalva was less predictive than diameter at rest and was only clinically significant in differentiating between Grade 1 and 2 varicocele. A standardized method for determining clinically relevant varicoceles on US would allow for improved patient counseling and clinical decision-making.

RESUMEN

Spontaneous thrombosis of the pampiniform venous plexus is a rare phenomenon, with limited cases reported in the literature. Accurate diagnosis necessitates a high index of suspicion, and scrotal Doppler ultrasound proves to be an effective diagnostic tool. This case report aims to elucidate the diagnostic intricacies of spontaneous thrombosis of the left pampiniform venous plexus, emphasizing the pivotal role of scrotal Doppler ultrasound. Additionally, we explore successful treatment modalities, including anticoagulation and bed rest, leading to complete resolution. This contribution aims to enhance clinical understanding, particularly in outpatient and emergency care settings, where accurate and timely diagnosis is imperative.

RESUMEN

The venous plexus of Rektorzik is a network of small veins, which enlace outside the wall of the internal carotid artery while it traverses the petrous part of the temporal bone. The anatomical and clinical issues related to the communication between the plexus of Rektorzik and other cranial venous structures were discussed in this paper.

Asunto(s)

RESUMEN

El objetivo de la presente monografía, fue actualizar la anatomía del Plexo Venoso Vertebral (PVV) del perro de relevancia clínico-quirúrgica y asimismo evaluar el cumplimiento de la Nómina Anatómica Veterinaria (NAV). Se realizaron búsquedas electrónicas utilizando 9 bases de datos, donde se revisaron un total de 49 fuentes bibliográficas. De éstas, 20 correspondieron a artículos científicos. El criterio de exclusión fue el de publicaciones con más de 10 años de antigüedad, con excepción de libros de anatomía veterinaria de referencia base. Publicaciones que no estuvieran escritas en inglés, español o portugués, fueron también excluidas. En general, en la literatura revisada, existió consenso de cuáles son los componentes del PVV, junto con una escueta descripción de éste. El componente del PVV que es más ampliamente descrito y con mayor dimensión es el Plexo Vertebral Interno Ventral (PVIV). La función de retorno venoso sanguíneo alternativo hacia el corazón es la más nombrada. La no existencia de válvulas en el PVIV, pudiese ser una condición promotora para la metástasis tumoral a través del PVV. A nivel quirúrgico, la hemorragia del PVV, representa un peligro no despreciable para la vida del paciente. Con respecto a lo revisado y discutido, se puede concluir que: i) a pesar de la escasa descripción anatómica del PVV se pudo comprender cómo éste está compuesto ii) el nivel de evidencia que avala las distintas capacidades funcionales del PVV es bajo, no obstante, la información de la presentación de la hemorragia del PVV en las distintas cirugías es mayor iii) las variadas referencias bibliográficas consultadas no respetaron la NAV actual para describir al PVV.

SUMMARY: This monograph aims to provide an update on the anatomy of the Vertebral Venous Plexus (VVP) of the dog with emphasis on its clinical and surgical relevance and to evaluate compliance of terms in the literature with Nomina Anatomica Veterinaria (NAV). Electronic searches were conducted using 9 databases, where a total of 49 bibliographic sources were reviewed. Of these, 20 consisted of scientific articles. Publications with more than 10 years old were excluded from review, except for basic reference veterinary anatomy books. Publications that were not written in English, Spanish or Portuguese were also excluded. In general, in the literature reviewed, there was consensus on what the components of the VVP are, along with a brief description of VVP. The most widely described component of the VVP is the Ven- tral Internal Vertebral Plexus (VIVP). The function of alternative venous blood return to the heart is the most frequently described. The absence of valves in the VIVP could be a promoting condition for tumor metastasis through the VVP. At the surgical level, VVP hemorrhage represents a non-negligible threat to the patient's survival. With respect to what has been reviewed and discussed, it can be concluded that: i) despite the scarce anatomical description of the VVP, it was possible to understand how it is composed ii) the level of evidence that supports the different functional capacities of the VVP is low, however, the information on the ocurrence of VVP hemorrhage in surgical procedures is greater and iii) the various bibliographical references describing the VVP did not comply with the current NAV.

Asunto(s)