Variations In Venous Drainage Research Articles

Submental Artery Island Flaps (SAIF) for Oral Cavity Cancer: Surgical Technique and Tertiary Care Experience.

In oral cancer surgeries, oncological outcomes take precious driverseat. But the copassengers like reconstruction, cosmesis, swallowing and speech outcomes deserve equivalent importance. Submental Artery Island Flaps (SAIF) provide an underutilized and extremely versatile option for reconstruction of defects following early stage oral cavity tumour resections. In this prospective observational analysis, we describe the technique, challenges and outcomes of SAIF at our tertiary care institute. Sixteen patients with Stage I and II oral cavity cancers were enrolled between June 2020 to May 2021. Verrucous carcinomas were five and well differentiated carcinomas were 11 patients. After tumour excision and neck dissections, defects were reconstructed with Pedicled submental flaps. Complications and functional outcomes were analyzed over two years. Nineteen percent were ladies and 81% were gentlemen. Median age was 52years. Tongue tumours formed majority with 56% cases. Largest skin paddle taken was 36cm2. Flap survival was 88%. There were variations in venous drainage of flaps which have been depicted in case figures. There was no report of orocutaneous fistula. Grade 3-4 speech satisfaction was achieved by 81.2% patients at 6months. Swallowing was excellent, grade 4-5 for 100% of patients at 6months. One patient had distant metastasis at 7months and died. SRLR (Submental flap Recurrences) and trismus were zero percent at two years. The unexplored field of submental flaps can be used for oral cancer reconstructions in a versatile way. Donor site easy closures, no scars on face, early resumption of daily activities and short hospital stay makes it one of the ideal options in early stage oral cavity defects.

Venous drainage of the left liver: an evaluation of anatomical variants and their clinical relevance

To evaluate the variations in venous drainage from the left liver. A retrospective evaluation was performed of all consecutive abdominal computed tomography (CT) examinations at a tertiary referral facility between 1 January and 30 June 2018. Osirix (Pixmeo SARL, Bernex, Switzerland) was used to examine the major hepatic veins and their tributaries in each scan. The classification of variants as proposed by Nakamura and Tsuzuki was used to describe the findings. The following information was collected: ramification pattern, number, length and diameter of middle (MHV) and left (LHV) hepatic vein tributaries. Two researchers collected data independently, and the average measurements were used as the final dimensions. Of 102 examinations evaluated, only 27 demonstrated the conventional venous drainage patterns. The LHV and MHV combined to form a common trunk that emptied into the inferior vena cava (IVC) in 75 (73.5%) cases. The common trunk had a mean length of 8.89 mm and mean diameter of 20.18 mm. Other patterns included Nakamura and Tsuzuki type I (27.5%), type II (29.4%) and type III variants (16.7%). In addition, 4.9% of patients had absent superior middle veins and 80% had supernumerary short hepatic veins (4%). Only 26.5% of patients in this population had conventional venous drainage from the left liver. Surgeons and radiologists in hepatobiliary practice should be aware of these variants in order to minimise morbidity when performing invasive procedures.

Evaluation of anterior third of superior sagittal sinus in normal population: Identifying the subgroup with dominant drainage.

Background/Object:The ligation and transection of anterior third of superior sagittal sinus (AT-SSS) is an important step to approach anterior skull base lesions. Some clinical studies have shown frontal lobe venous infarct following such surgical procedures questioning the safety of its ligation. We have studied the variations in venous drainage patterns to AT-SSS in the normal population using postcontrast magnetic resonance venogram (MRV). A novel scoring system to recognize the subgroup with dominant venous drainage from frontal lobes has been described.Materials and Methods:In this study, 60 three-dimensional contrast-enhanced (CE) MRVs were obtained from those cases being evaluated for a headache not harboring any intracranial mass lesion. The AT-SSS with all its draining veins was studied in detail. Morphology of individual veins such as length, caliber, tributaries, and angulation with AT-SSS was studied, and a numerical value of 0 or 1 was assigned for each of the above parameters. Summing up these scores derived from the individual cortical veins quantified the drainage of AT-SSS.Results:There are 3–4 veins on either side draining to AT-SSS. Barely, 3% of the veins had > 3 tributaries. Only 6.6% of veins had a caliber >3 mm, and 16.5% drained at acute angles to AT-SSS. About 26% of the veins did cross at least half of the lateral frontal lobe. We found in 26 individuals the AT-SSS score was 0–2, in 22 it was 3–5 and, in only in 12 (20%) the score was 6 or more (dominant drainage).Conclusion:There are anatomical variations in venous drainage of frontal lobes into AT-SSS. Those with dominant drainage are likely to develop venous congestion and complications if sacrificed. It is possible to identify these individuals on the basis of venous drainage pattern as shown in CE-MRV.

Brainstem congestion due to carotid-cavernous fistula via a shunt from the external carotid artery

Venous congestion of the brainstem is an extremely rare complication of carotid-cavernous fistula (CCF). Here, we report a case in which MR imaging revealed characteristic changes associated with a simultaneous increase in pressure in the ophthalmic vein and anterior pontomesencephalic vein. Our patient was a 76-year-old woman who had been diagnosed with spinocerebellar ataxia type 31, had exophthalmos, conjunctival congestion in her left eye, worsening dysarthria, and gait instability. Ten days later, she was admitted to our hospital. A neurologic examination conducted upon admission revealed mydriasis, loss of light reflex, impaired superolateral movement of the left eye, and worsening ataxia with gait difficulty and slurred speech. Laboratory examinations revealed only high levels of serum anti-cardiolipin IgG antibody and the presence of cerebrospinal fluid myelin basic protein, but no other suggestive data of an inflammatory event. T2-weighted MRI revealed a dilated left superior ophthalmic vein and hyperintensity of the pons, mainly on the left side (Fig. 1a), which was depicted as low signal area with a linear high signal lesion in diffusion-weighted images (Fig. 1c), and T1-weighted imaging revealed an isointense mass with ring-shaped contrast enhancement after injection of gadolinium (Fig. 1b). Cerebral angiography confirmed the presence of a very weak, direct, highflow CCF in the left external carotid artery (Fig. 1d, e). The MR venography and venous phase of the angiography did not show any occlusion of veins. Methionine positron emission tomography revealed no tracer uptake in the lesion, which excluded the possibility of a brain tumor. Her symptoms were rapidly getting well before we tried an endovascular treatment. At 4 months, the MRI images showed a high signal spot at the left cerebellar peduncle and slight high signal on the left side of the pons (Fig. 1a). Most cases of idiopathic and traumatic CCF have been reported to be caused by dural arteriovenous fistulas (DAVF) [1]. The providing angiography images showed a shunt from the external carotid artery to the cavernous sinus. According to the Barrow classification, we diagnosed this case as an indirect fistula [2]. The pathomechanisms of venous congestion of the brainstem in CCF remain unknown, but variations in the drainage pattern of the superior petrosal sinus (SPS) and engorged veins in the surrounding brainstem were speculated to be important factors in most of the cases. A large flow volume shunted via the CCF [3, 4], occlusion of the superior or inferior petrosal sinus [5, 6], thrombosis of the dural sinuses or veins of the posterior fossa [4], and variations in venous drainage [7] have been speculated to be primary triggers for venous congestion. The most likely pathomechanism in this patient is that the CCF initially drained via the ophthalmic vein and recruited the prepontine venous plexus for drainage following partial thrombosis of the cavernous sinus. For the cause of the partial thrombosis, we speculate the possible mediation of antiphospholipid-related antibodies because antiphospholipid antibodies are known to be associated with cerebral venous thrombi, and recent studies have suggested that venous congestion and retrograde flow may cause a dysfunctional venous circulation [8]. Y. Ito N. Sanjo (&) K. Ishikawa O. Tao T. Yokota H. Mizusawa Department of Neurology and Neurological Science, Graduate School of Medical and Dental Science, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan e-mail: n-sanjo.nuro@tmd.ac.jp

Anatomical variation of cerebral venous drainage: the theoretical effect on jugular bulb blood samples.

Recent studies have demonstrated significant variation in bilateral jugular venous oxygen saturation measurements which may be of clinical significance. We have therefore measured variations in normal dural sinus venous drainage to assess the possible effects of normal anatomical variations on measured jugular venous oxygen saturation. Normal volunteers (n = 25) were imaged using magnetic resonance venography to demonstrate variations in venous anatomy. Flow was measured in the superior sagittal sinus and bilaterally in the transverse sinus, sigmoid sinus proximal to the jugular bulb and proximal jugular vein using phase difference magnetic resonance imaging. Examination of magnetic resonance venogram images showed considerable variability in the symmetry of transverse sinus flow. Complete absence of one transverse sinus was seen in four cases and significant asymmetry in the size of the transverse sinuses was present in 13. Quantitative flow studies demonstrated that the ratio of superior sagittal sinus to combined jugular bulb flow showed remarkably little variation (0.46 +/- 0.06). Measurements of transverse sinus flow showed significant asymmetry (< 40% of superior sagittal sinus flow in one transverse sinus) in 21 of 25 volunteers. The effect of the observed asymmetry on jugular venous oxygen saturation was modelled based on the assumption of either a supratentorial or infratentorial lesion. This model predicted significant asymmetry in jugular venous oxygen saturation measurements (> 10%) in 65% of cases with a supratentorial lesion which is in close agreement with clinical observations. This study suggests that normal variations in venous drainage may account for observed asymmetry in jugular venous oxygen saturation measurements.

Segmental pancreatic autotransplantation in the pig.

The pig has been considered unsuitable for experimental pancreatic transplantation. In order to develop a model for segmental transplantation, the vascular anatomy was studied in 41 pigs. No variation in venous drainage of the pancrease was found. In contrast, 3 variations of arterial supply were noted. In 29 of the pigs (71% [95% confidence limits 64-84]), 1 main pancreatic artery to the body and tail of pancreas arose from the splenic artery about 1-2 cm from its origin from the coeliac trunk (type 1). In 6 pigs (14.5%, 6.5-29.2), 1 main pancreatic artery emerged from the splenic artery very close to its origin from coeliac trunk (type 2). In 6 pigs (14.5%, 6.5-29.2), the only pancreatic artery supplying the body and tail of pancreas came from the common hepatic artery (type 3). Taking the vascular anatomy into account, 37 pigs were totally pancreatectomized and autotransplanted segmentally. The graft consisted of the body and tail and corresponded to approximately 60% of the entire gland. The pancreatic duct was occluded with neoprene. The left kidney was removed in all animals. In 19 of the grafts, the venous drainage was to the portal vein. In the remaining 18, the renal vessels were used for vascular anastomosis to the graft. The success rate was 68.42% and 72.22%, respectively. The median follow-up was 9 months (3-15). All transplanted pigs were normoglycemic. It is concluded that the pig is suitable for experimental pancreatic autotransplantation studies if the vascular variations are adequately dealt with.

The Pontomesencephalic Veins

The pontomesencephalic veins have in the past been beautifully demonstrated in roentgenograms of anatomical specimens (2, 3). A few authors have also identified these veins on vertebral angiography performed during life (1, 3–5, 10, 11). The present work is an attempt to investigate the pontomesencephalic venous system in greater detail, using clinical neuroradiological means. The variable roentgenographic appearances of the pontomesencephalic veins, their relationship to the anterior border of the brain stem, and their frequency of visualization on vertebral angiography will be discussed. Anatomy The blood from the major part of the pons and mesencephalon drains in an anterior direction (Fig. 1). Numerous parenchymal veins, on reaching the anterior and anterolateral surfaces of the brain stem, usually empty into larger, longitudinal venous channels which are closely associated with the anterior border of the brain stem (2–4). Occasionally, there may be only a single, midline, longitudinal vein situated between the basilar artery and the brain parenchyma (2). This fact and the frequent impression of seeing only one longitudinal vein in front of the brain stem on lateral roentgenograms of vertebral angiography probably prompted Huang and Wolf (3), for the sake of simplicity, to speak of the “anterior pontomesencephalic vein.” Hassler (2), however, states that anatomically there is generally a plexus of longitudinal veins on each side of the pons, a few millimeters from the midline and fairly parallel to the basilar artery. The venous plexus anterior to the pons is continuous with a similar plexus in the interpeduncular fossa and anterior to the medulla oblongata and spinal cord. The pontomesencephalic veins in most cases drain primarily into (a) the superior petrosal sinuses, mostly through the petrosal veins, and (b) peduncular veins which pass laterally around the upper margins of the cerebral peduncles and empty into the basal veins of Rosenthal or posterior mesencephalic veins. Some drainage also occurs into the inferior petrosal sinuses and through bridging veins into the basilar venous plexus along the clivus (2–4, 6–8, 10, 11). With variation in venous drainage, the pontomesencephalic veins may in part empty into the uncal vein (which usually drains into the cavernous sinus) or the lateral anastomotic mesencephalic vein (3, 11). Material On a review of the 1967–1968 vertebral angiographies performed at Ullevål Hospital, we selected for further study the first 100 examinations encountered with a technically satisfactory demonstration of the posterior cranial fossa veins. Thirty-seven patients were males, and 63 were females. Their ages ranged from five months to seventy-four years (Table I). The lateral views were used as the basis for this screening, which was an inspection of the posterior cranial fossa veins in general.