Venous Outlet Research Articles

Thoracic Outlet Syndrome.

Thoracic outlet syndrome is a complex syndrome that manifests with symptoms based on the presumed injury or impairment of the neurovascular structures in the thoracic outlet space with its intricate anatomy and pathophysiology. The thoracic outlet is a specific anatomical region with three distinct anatomical spaces - interscalene triangle, the costoclavicular space, and the retro-pectoralis minor space. Thoracic outlet syndrome is classified into neurogenic, venous, and arterial thoracic outlet syndrome and often poses diagnostic challenge to implicate a specific condition or cause. Many cases of thoracic outlet syndrome can be effectively managed through conservative measures, but patients with refractory symptoms may warrant surgical intervention. Modalities such as intramuscular anesthetic and botulinum toxin injections hold promise as diagnostic, therapeutic, and prognostic procedures. Further research and collaboration are needed to develop algorithms for diagnosis and treatment of thoracic outlet syndrome symptoms. This review aims to explore our understanding of thoracic outlet syndrome, with a focus on current evidence and emerging trends.

End-to-Side Venous Anastomosis with IJV: Improving Outcomes of Microvascular Anastomosis in Head and Neck Reconstruction

Abstract Background End-to-side (ES) venous anastomosis is an established approach for head and neck reconstruction and has several benefits over conventional end-to-end (EE) anastomosis. However, this is not preferred by all, which may be due to technical preferences for an EE anastomosis by many surgeons. We present here our experience of routine ES venous anastomosis for head and neck reconstruction over the past 8 years. Materials and Methods All consecutive head and neck malignancy patients reconstructed with free flap and our routine ES internal jugular vein (IJV) anastomosis approach between 2015 and 2023 have been included in this study. Flap-related variables are reviewed retrospectively. Results Reconstruction was done with a total of 585 free flaps including 303 radial forearm flaps (RFFs), 143 osteocutaneous fibula flaps (OCFFs), and 139 anterolateral thigh (ALT) flaps. The flap survival rate was 573/585 (97.95%). Re-exploration and salvage rates were 45/585 (7.69%) and 38/45, respectively (84.44%). Conclusion Routine use of ES anastomosis simplifies microvascular anastomosis by avoiding efforts related to the selection of recipient vessels, providing a single large-caliber venous outlet, the favorable geometric orientation of the pedicle, and ease of re-exploration. The vascular anastomosis for RFF, ALT, and OCFF flap is feasible with 7–0 sutures and under 4.5X loupe magnification with this approach quite conveniently with similar outcomes to the reported flap survival rate in the contemporary practice.

Boney abnormalities cause arterial, venous, and/or neurogenic thoracic outlet syndrome.

Thoracic outlet syndrome (TOS) is a rare condition caused by compression of the neurovascular structures within the thoracic outlet. Different classifications of TOS exist depending on the neurovascular structure being compressed: neurogenic, venous, or arterial. Any of these forms can present independently or coexist with one other. TOS symptoms are sometimes precipitated by the presence of boney abnormalities that often require surgical intervention for ultimate resolution. This retrospective review will examine the presentations and outcomes of patients with TOS whose cause was a boney abnormality. A total of 73 patients who underwent thoracic outlet surgery between 2016 and 2021 were retrospectively reviewed via electronic medical records. Twelve (16%) patients demonstrated boney abnormalities on presentation causing their symptoms. The patients with boney abnormalities were analyzed based on venous, arterial, or neurogenic TOS diagnosis. Of the 12 patients with boney abnormalities, 5 were classified as venous TOS, 6 patients as neurogenic TOS, and 1 as arterial TOS. The boney abnormalities were as follows: venous TOS: three clavicular fractures, one nonfused congenital clavicle, and one residual rib; neurogenic TOS: three fractured first ribs, one fractured clavicle, and two cervical ribs; and arterial TOS: fused first and second rib with bilateral cervical ribs and arterial compression. Postoperatively, there were no artery, vein, or nerve injuries. Five patients had a pneumothorax treated over night with a chest tube, and one patient had a superficial wound infection. The median hospital stay was 1day. All patients completed physical therapy after surgery. All patients have symptom resolution at follow-up. Patients with boney abnormalities constitute about one-fifth of patients who can present with all three forms of TOS: neurogenic, arterial, and venous, and some will have more than one of these presentations. Results in patients undergoing surgery with boney abnormalities causing thoracic outlet syndrome are excellent with symptom resolution and without substantial complications.

Prediction of the anastomosis angle of arteriovenous fistula in hemodialysis to standardize the surgical technique.

Arteriovenous fistula (AVF) is the preferred route of vascular access in hemodialysis. The primary reason of fistula failure is intimal hyperplasia (IH), which leads to stenosis. Wall shear stress (WSS) and disturbed flow are the critical parameters in the formation of IH. The primary goal of this study is to explore the influence of anastomosis angle on WSS and venous outflow rate, as well as to find the ideal angle of anastomosis for AVF to standardize surgical technique. Three-dimensional idealized geometries of end-to-side type AVF for the five various angles of anastomosis are considered in this study. The WSS, blood flow rate at the venous outlet for non-Newtonian, pulsatile blood flow are calculated using a numerical simulation technique. The WSS is higher at 75° compared to other angles and least at 45° for pulsating arterial inflows. The WSS is moderate at 30°, 60° and 90°. On the arterial bed and outer wall of the vein, immediately after the anastomosis, the recirculation zone is observed. At an angle of 45° and 90° anastomosis, the outflow rate is greater at distal venous end. If one believes that high wall shear stress causes IH within the AVF, the results suggest that the AVF should be formed at a 45° angle to avoid IH. However, if one believes that low wall shear stress causes IH within the AVF, the results suggest that AVF should be formed at either 30° or 75° to avoid IH. The findings spotlight the importance of anastomosis angle in determining AVF hemodynamics.

Venous outflow stenting for symptomatic developmental venous anomaly.

Developmental venous anomaly (DVA) is one of the commonest vascular malformations in the brain but rarely symptomatic. Various pathomechanisms such as mechanical compression, increased in-flow into DVA or outflow obstruction have been described as causative factors in symptomatic DVAs. We report a unique case of a pontomedullary DVA with venous outflow obstruction causing progressive neurological worsening in a young adult despite anticoagulation, who was treated with a novel approach of venous outlet stenting of the collector vein with favorable outcome. In carefully selected cases, this endovascular treatment can be an effective and safe alternative when other measures fail.

The clinical outcome of balloon-assisted maturation procedure between autogenous radiocephalic fistula and brachiocephalic fistula in a single-center experience

ObjectiveBalloon-assisted maturation (BAM) by an endovascular method plays an important role in treating an immature arteriovenous fistula. However, the results between radiocephalic fistula and brachiocephalic fistula were rarely reported. This retrospective study aimed to investigate the effectiveness and outcome of BAM in different sites of autogenous arteriovenous fistulas. MethodsThis single-center retrospective study included patients who underwent BAM procedures from January 2015 to December 2016. Of 148 patients, 117 and 31 patients had a radiocephalic fistula (RC) and a brachiocephalic fistula (BC), respectively. The primary outcome was BAM success. Data regarding fistula lesions, balloon types and size, frequency of procedures, and maturation time were collected for BAMs. The secondary outcome was the patency of a fistula in the follow-up period. ResultsNo difference was observed in procedure of BAM frequency between the RC and BC groups. The total success rate was 77.7%, without significant difference between the RC and BC groups (81.20% vs 64.50%; P = .055). Within the procedures, the culprit lesion of juxta-anastomosis segment (73.5% vs 25.5%; P < .001) and arterial inlet (21.2% vs 7.8%; P = .04) were more common in the RC group, whereas the venous outlet was more common in the BC group (88.2% vs 57.7%; P < .001). Both groups had an equivalent patency rate after the BAM within the follow-up period (P = .272). ConclusionsBAM was an effective procedure for immature fistulas, without significant difference between RCs and BCs. Through the procedure, the culprit lesions causing non-maturation were found to be different between the two groups. The patency rate between the two groups after surgery seems to be equivalent within the follow-up period.

Venous and Arterial Thoracic Outlet Syndrome Requiring Surgical Intervention: Two Case Reports

Background: Thoracic outlet syndrome represents a spectrum of diseases depending on the structures involved. Most cases of thoracic outlet syndrome (TOS) are neurogenic while arterial and venous TOS constitute only 5% of the cases. Paget-Schroetter syndrome represents an acute complication of venous thoracic outlet syndrome (vTOS) commonly occurring in physically active individuals participating in strenuous upper body exercises. Arterial thoracic outlet syndrome (aTOS) is usually associated with bony abnormalities. We discuss one patient of each type who presented with acute thrombosis to illustrate the different associated factors and treatment options. Case Report(s): An 18-year-old Hispanic male presented with six days of left upper extremity (LUE) edema and pain that began following an upper body exercise. He was treated by pharmacomechanical thrombectomy followed by ultrasound assisted catheter-directed thrombolysis. Subsequently the patient underwent trans axillary surgical decompression of the thoracic outlet. A 59-year-old South Asian woman presented with worsening LUE pain, weakness and paresthesia of 10 days duration. She underwent pharmacomechanical thrombectomy with angioplasty followed by supraclavicular thoracic outlet decompression. Conclusions: Treatment of TOS presenting with thrombosis should consist of prompt thrombectomy followed by surgical decompression.

Transarterial Embolization of Intracranial Arteriovenous Fistulas with Large Venous Pouches in the Form of Venous Outlet Ectasia and Large Venous Varix or Aneurysm : Two Centers Experience.

ObjectiveThere are different types of cerebral vascular malformations. Pial arteriovenous fistulas (PAVFs) and dural arteriovenous fistulas (DAVFs) are two entities; they consist of one or more arterial connections to a single venous outlet without a true intervening nidus. The high turbulent flow of PAVFs and aggressive DAVFs with cortical venous reflux can result in venous outflow varix and aneurysmal dilatation. They pose a significant challenge to transvenous embolization (TVE), stereotactic radiosurgery, and surgical treatment. We aim to share our centers’ experience with the transarterial embolization (TAE) for arteriovenous fistulas (AVFs) with large venous pouches and to report the outcome. MethodsThe authors’ two institutions’ databases were retrospectively reviewed from February 2017 to February 2021. All patients with intracranial high flow PAVFs and aggressive DAVFs with venous outlet ectasia and large venous varix and were treated by TAE were included. ResultsFifteen patients harboring 11 DAVFs and four PAVFs met our inclusion criteria. All patients underwent TAE in 17 sessions. Complete angiographic obliteration was achieved after 14 sessions in 12 patients (80%). Four patients (25%) had residual after one TAE session. Technical failure was documented in one patient (6.7%). Fourteen patients (93.3%) had favorable functional outcome (modified Rankin score 0–2). ConclusionsTAE for high flow or aggressive intracranial AVFs is a safe and considerable treatment option, especially for those associated with large venous pouches that are challenging and relatively high-risk for TVE.

Transarterial embolization in dural arteriovenous fistulas under sinus balloon protection using the SHOURYU supercompliant balloon

ObjectiveTransarterial embolization under intrasinus balloon protection is an efficient treatment strategy for intracranial arteriovenous fistula. Ordinary balloon protection methods using the Copernic RC balloon may occlude the normal drainage route, and the occurrence of venous complications is concerning. The aim of this study was to report the efficacy of the supercompliant SHOURYU balloon catheter for intrasinus balloon protection while preserving the normal venous outlet. MethodsEighteen patients with dural arteriovenous fistulas who were treated with transarterial embolization under intrasinus balloon protection between April 2011 and July 2020 were included. All lesions were treated with transarterial embolization under intrasinus balloon protection using the SHOURYU balloon catheter. Clinical and angiographic data were retrospectively collected, and the occlusion rate, complications, and clinical outcomes were analyzed. ResultsNine men and nine women were treated, and their average age was 61.1 years. Fistulas were located at the transverse-sigmoid sinus (n = 13), superior sagittal sinus (n = 3), tentorial sinus (n = 1), and around the torcular Herophili (n = 1). Ten patients were classified as Borden typeⅠand eight as Borden type Ⅱ. Complete (n = 9) or near-complete (n = 4) occlusion was achieved in 72.2% of the patients. Periprocedural complications, but no venous complications were observed in two patients. Symptoms were not aggravated after treatment. ConclusionsTransarterial embolization under intrasinus balloon protection using the SHOURYU balloon catheter is effective and safe for treatment of dural arteriovenous fistulas while maintaining the patency of the venous sinus.

Venous thoracic outlet syndrome and Paget-Schroetter syndrome

Venous thoracic outlet syndrome represents a relatively rare but important diagnosis in the adolescent population with increasing recognition. Compression of the subclavian vein within the costoclavicular space can lead to episodic venous outlet obstruction in the upper extremity, with edema, rubor and functional symptoms. Over time, cumulative injury and compression can lead to thrombosis of the vein, referred to as “effort thrombosis” or the Paget-Schroetter syndrome. This progression can lead to the need for acute management of the venous thromboembolism, requirement for thoracic outlet decompression surgery and the potential for long-term sequelae such as post-thrombotic syndrome. Management is focused on clot minimization, anticoagulation during the period of endothelial injury and inflammation and surgical decompression via first rib resection, anterior scalenectomy and venolysis to remove external compression of the vein. This manuscript reviews the diagnosis, evaluation and treatment of venous thoracic outlet syndrome and Paget-Schroetter syndrome.

Completely Thoracoscopic 3-Port Robotic First Rib Resection for Thoracic Outlet Syndrome

BackgroundIn thoracic outlet syndrome, the constriction between bony and muscular structures leads to compression of the neurovascular bundle to the upper extremity. Traditional surgical techniques using supraclavicular, infraclavicular, or transaxillary approaches to remove the first rib do not usually allow good exposure of the entire rib and neurovascular bundle. We have therefore developed a robotic approach to overcome these limitations. MethodsBetween January 2015 and November 2020, 38 consecutive first rib resections for neurogenic, venous, or arterial thoracic outlet syndrome were performed in 34 patients at our institutions. For our completely portal approach, we used two 8-mm working ports and one 12-mm camera port. ResultsThe surgery time was between 71 and 270 minutes (median ± SD: 133 ± 44.7 minutes) without any complications. Chest tube was removed on postoperative day 1 in all patients and the hospital stay after surgery ranged from 1-7 days (2 ± 2.1 days). No relevant intraoperative or postoperative complications were observed and complete or subtotal resolution of symptoms was seen in all patients. ConclusionsThe robotic technique described here for first rib resection has proven to be a safe and effective approach. The unsurpassed exposure of the entire first rib and possibility for a robotic-assisted meticulous surgical dissection has prevented both intraoperative and postoperative complications. This makes this technique unique as the safest and most minimally invasive approach to date. It helps improve patient outcomes by reducing perioperative morbidity with an easily adoptable procedure.

The first known case of vaccine‐induced thrombotic thrombocytopenia in Australia

The first known case of vaccine‐induced thrombotic thrombocytopenia in Australia

Outcomes of Single Anastomoses for Superficial and Deep-System Venous Drainage of Radial Forearm Free Flaps.

ObjectiveVenous insufficiency occurs in radial forearm free flaps (RFFFs) when either the deep venous system (DVS) or superficial venous system (SVS) is used as the venous outlet. We report our experience using the antecubital perforating vein (APV) in a single-vessel anastomosis to the median-cubital or cephalic vein to drain both systems.Study DesignRetrospective review.SettingSingle, academic, tertiary care center.MethodsData were collected from 72 patients who underwent RFFF from October 2009 to January 2017. In all cases, DVS and SVS were dissected, and an APV single-vessel anastomosis was attempted.ResultsAnatomical variations precluded single-vessel anastomosis in 11 (15.3%) cases. In 61 (84.7%) cases, single-vessel anastomosis produced unobstructed drainage for DVS and SVS without intrinsic venous insufficiency. Venous thrombosis and total loss occurred in 2 (3.3%) and 1 (1.6%) patients, respectively. Proximal dissection of the cephalic vein addressed a vessel-depleted neck in 3 cases.ConclusionThe antecubital perforating vein is present and functional in most patients, allowing for single anastomosis techniques for RFFF. Antecubital perforators capture DVS and SVS outflow through a single, extended venous pedicle, eliminating the risk of venous insufficiency and need for vein grafts.

Outcomes of venous bypass combined with thoracic outlet decompression for treatment of upper extremity central venous occlusion

BackgroundUpper extremity central venous stenosis results from a variety of environmental and anatomic conditions, including venous thoracic outlet syndrome, the presence of device leads or catheters, and the turbulence created by the presence of arteriovenous fistulas or grafts. In cases of total occlusion, especially at the bony costoclavicular junction, options for endovascular treatment and open venous reconstruction are limited and bypass grafting may be needed. We describe our experience with venous bypass combined with thoracic outlet decompression in a cohort of symptomatic patients with subclavian vein occlusion. MethodsA prospectively collected database of patients was queried for patients treated for central venous obstructive disease with venous bypass in the setting of both symptomatic venous thoracic outlet syndrome and ipsilateral arteriovenous access from July 2012 to December 2017. All but one patient presented with arm swelling and had either failed to respond to or were unsuitable for endovenous therapy. One patient desired elective removal of a venous stent because of pain and anxiety. Operative procedures were performed at the discretion of the operating surgeon. ResultsFourteen patients (eight men; average age, 42 years) underwent open thoracic outlet decompression with first rib resection (n = 11) or claviculectomy (n = 4). Indication for treatment was dialysis-associated venous outlet obstruction in five, effort thrombosis (Paget-Schroetter syndrome) in seven, presence of a venous implantable cardioverter-defibrillator lead in one, and patent but painful venous stent in situ with significant anxiety. Nine patients required first interspace sternotomy for exposure of the proximal subclavian vein. One patient with acute Paget-Schroetter syndrome had been treated with preoperative thrombolysis without resolution; all others were chronically occluded. Bypass conduit was jugular vein in one, bovine carotid artery graft in two, paneled great saphenous vein in two, femoral vein in eight, and polytetrafluoroethylene in one. Mean operative time was 187 (±45) minutes, with mean estimated blood loss of 379 (±209) mL. There were two early graft thromboses that were revised with jugular venous turndown and femoral vein bypass, respectively. All patients experienced immediate symptom relief. Morbidity included two graft thromboses, two instances of wound dehiscence, two operative site hematomas, non-ST elevation myocardial infarction, vein harvest site infection, polytetrafluoroethylene graft infection, and phrenic nerve injury. At a mean follow-up of 357 (±303) days, primary assisted patency and secondary patency for the entire cohort were 71.4% and 85.7%, respectively, with 100% primary assisted patency among those with femoral vein conduit. At last follow-up, 13 of the 14 living patients (93%) remained symptom free. ConclusionsIn our experience, venous bypass combined with thoracic outlet decompression achieves symptomatic relief in approximately 90% of patients with symptomatic upper extremity central venous occlusion, with morbidity limited to the perioperative period.

Functional anatomy of the semi-membranosus muscle: main thigh pump and derivative route of the Hunter’s canal

Introduction: Our objective is to highlight the role of the semi-membranosus muscle, which is surprisingly not described in the major books of anatomy, as main thigh pump in the venous return [1]. Material and methods: Latex injection of fresh cadavers followed by anatomical dissection and colored segmentation of the whole venous network of 300 lower limbs, 3D reconstructions by CT venography of 1000 CVD patients are at the basis of this study. Results: The venous arcades of the semi-membranosus muscle constitute a main deep collateral route by-passing the narrowed area of the Hunter’s canal. This anatomical study clearly shows that these venous arcades are regularly connected:(Figure 1) Figure 1. Arcades of the semimembranosus muscle (in dark blue). The 2 lower are connected to the popliteal vein (in light blue). The 2 higher to the deep vein of the thigh (in green). Notice the valves (in yellow) • By their 2 lower branches to the popliteal vein • By their 2 higher branches to the deep femoral vein. Consequently, they constitute a derivative route of the femoral axis, explaining their dilatation in case of stenosis of the Hunter’s canal outlet. Similarly, in a physiological situation, the whole amount of blood ejected by the powerful calf pump through the popliteal vein cannot always reach the femoral vein through the Hunter’s canal: the arcades then play the role of a safety valve. Moreover, the veins of the semi-membranosus muscle constitute a main thigh pump: they push up the blood towards the femoral crossroad at the root of the limb. Discussion and conclusion: The veins of the semi-membranosus should be systematically investigated by USD : their dilatation is the witness of venous outlet syndrome of the Hunter’s canal which is a major cause of femoral vein thrombosis. USD investigation should be systematically carried out at that levels to prevent future deep vein obstruction.

Removal of Protein-Bound Uremic Toxins during Hemodialysis Using a Binding Competitor.

Current hemodialysis techniques fail to efficiently remove the protein-bound uremic toxins p-cresyl sulfate and indoxyl sulfate due to their high degree of albumin binding. Ibuprofen, which shares the same primary albumin binding site with p-cresyl sulfate and indoxyl sulfate, can be infused during hemodialysis to displace these toxins, thereby augmenting their removal. We infused 800 mg ibuprofen into the arterial bloodline between minutes 21 and 40 of a conventional 4-hour high-flux hemodialysis treatment. We measured arterial, venous, and dialysate outlet concentrations of indoxyl sulfate, p-cresyl sulfate, tryptophan, ibuprofen, urea, and creatinine before, during, and after the ibuprofen infusion. We report clearances of p-cresyl sulfate and indoxyl sulfate before and during ibuprofen infusion and dialysate concentrations of protein-bound uremic toxins normalized to each patient's average preinfusion concentrations. We studied 18 patients on maintenance hemodialysis: age 36±11 years old, ten women, and mean vintage of 37±37 months. Compared with during the preinfusion period, the median (interquartile range) clearances of indoxyl sulfate and p-cresyl sulfate increased during ibuprofen infusion from 6.0 (6.5) to 20.2 (27.1) ml/min and from 4.4 (6.7) to 14.9 (27.1) ml/min (each P<0.001), respectively. Relative median (interquartile range) protein-bound uremic toxin dialysate outlet levels increased from preinfusion 1.0 (reference) to 2.4 (1.2) for indoxyl sulfate and to 2.4 (1.0) for p-cresyl sulfate (each P<0.001). Although median serum post- and predialyzer levels in the preinfusion period were similar, infusion led to a marked drop in serum postdialyzer levels for both indoxyl sulfate and p-cresyl sulfate (-1.0 and -0.3 mg/dl, respectively; each P<0.001). The removal of the nonprotein-bound solutes creatinine and urea was not increased by the ibuprofen infusion. Infusion of ibuprofen into the arterial bloodline during hemodialysis significantly increases the dialytic removal of indoxyl sulfate and p-cresyl sulfate and thereby, leads to greater reduction in their serum levels.

The clinical value of venous drainage in patients with spinal dural arteriovenous fistula

BackgroundSpinal dural arteriovenous fistulas (sdAVF) with rapid deterioration are a known clinical phenomenon but have been rarely reported in the past. Clinical and radiologic features of these fistulas are analyzed for this study. Material and methodsWe retrospectively reviewed our medical records for sdAVF patients who were treated in our center between 2006 and 2017. Our cohort was dichotomized in two groups; a) patients with acute/ subacute onset and rapid deterioration within a period of ≤6 months, b) patients with chronic progressive deterioration within a period of >6 months. MR findings at time of diagnosis were re-evaluated. All patients were treated microsurgically. Follow-up data were included. ResultsData of forty patients were available for this study. Rapid deterioration was observed in 13/40 (32.5%) patients. AL-score at time of diagnosis did not differ between both groups (3.2 ± 1.2 vs 3 ± 2, p = .78). Patients with rapid deterioration showed significantly more prominent arterialized perimedullay veins at time of diagnosis (p < .05). At the last follow-up (53 ± 3 months), patients with rapid deterioration improved up to one point on AL-scores (from 3.2 ± 1.4 to 2 ± 1.6) and those with chronic progressive deterioration were unchanged (from 3 ± 1.6 to 3 ± 1.7). ConclusionPatients with rapid deterioration in our group (32.5%) presented with a significantly more prominent appearance of the arterialized perimeduallry veins. This may reflect, in the earlier phase of the disease, a better compensation of the venous hypertension as well as the associated venous outlet disorder of the spinal cord. This may also explain the better outcome of these patients.

Endovascular Treatment of Idiopathic Intracranial Hypertension with Stenting of the Transverse Sinus Stenosis.

For many years, the pathophysiology of idiopathic intracranial hypertension (IIH) was interpreted as “secondary intracranial hypertension,” and IIH was considered to be caused by brain edema due to obstructive sleep apnea. Another theory proposed cerebrospinal fluid (CSF) absorption impairment due to excessive medication with vitamin A derivatives. Other reports pointed out the importance of obesity, which may cause an impairment of intracranial venous drainage due to elevated right atrial pressure. Patients with medically refractory IIH have traditionally undergone a CSF diversion. Venous outlet impairment on IIH has recently been reported as a causative or contributory cause, and thus focused venoplasty of the stenotic sinus with a stent has emerged as a new treatment strategy. We report the cases of two patients who presented with headache and papilledema with IIH. They successfully underwent stent placement at the stenosis of the transverse sinus and experienced complete resolution of symptoms.

An analysis of the anatomic route of the hypoglossal nerve within the hypoglossal canal using dynamic computed tomography angiography in patients with anterior condylar arteriovenous fistulas

ObjectiveThe venous outlet of anterior condylar arteriovenous fistulas (AC-AVFs) often empties into the anterior condylar vein (ACV). Hypoglossal nerve palsy is one of the major complications after transvenous embolization (TVE) for the AC-AVF within the hypoglossal canal. However, no studies have investigated the route of the hypoglossal nerve within the hypoglossal canal in AC-AVF. The aim of the current study is to retrospectively verify the anatomical route of the hypoglossal nerve within its canal using dynamic computed tomography angiography (CTA) in order to facilitate the safe TVE for AC-AVF. Patients and methodsWe included five patients with AC-AVF from 2011 to 2017. Dynamic CTA was performed on all patients. When the ACV was well-visualized by dynamic CTA, the hypoglossal nerve could be recognized as a less-intense structure within the surrounding enhanced vasculatures and the nerve route within the canal was analyzed. We also analyzed the location of the fistulas by digital subtraction angiography and cone-beam computed tomography. ResultsIn all five patients, the filling defect of the hypoglossal nerve ran through the most caudal portion of the hypoglossal canal. The fistulous pouches were located in the hypoglossal canal in three cases, and in the jugular tubercle venous complex in two cases. In all three cases with AC-AVF in the hypoglossal canal, the fistulous pouches were located in the superior wall of the hypoglossal canal, which means superior to the ACV. We performed TVE in four patients and none developed post-therapeutic hypoglossal nerve palsy. ConclusionIn the current study, dynamic CTA is useful for detecting the hypoglossal nerve within the hypoglossal canal. The hypoglossal nerve usually ran the bottom of its canal and the fistulous pouches were usually located at the superior aspect of the canal opposite side to the hypoglossal nerve. Accordingly, the selective embolization within the fistulous pouch located in the superior aspect of the ACV including jugular tubercle venous complex can reduce the risk of hypoglossal nerve palsy.

Evaluating the Feasibility of Isolated Pancreatic Perfusion for Chemotherapy Using Computed Tomography: An Experimental Study in Pig Models.

Percutaneous isolated pancreatic perfusion (PIPP) is performed along with interventional radiology techniques to obtain high drug concentration by occluding the arterial inlet and venous outlet of the pancreas. The experimental study aimed to evaluate the contrast distribution in PIPP under different flow rates with or without anterior mesenteric artery (AMA) occlusion. This study was approved by a local animal experiment ethics committee. Nine pigs were divided into Groups 1, 2, and 3, by infusion rates of 12, 24, and 36mL/min. Groups 4 and 5 (3 pigs each) and Group 6 (2 pigs) underwent PIPP at the same respective infusion rates with and without AMA occlusion. Computed tomography (CT) arteriography was performed during PIPP with nonionic contrast media. The enhanced volume was calculated by adding the enhanced area in each slice using 1.25-mm axial images. The percent enhanced volume to the whole pancreas (%eV) was used to simulate drug distribution; the result was compared among groups. Without AMA occlusion, a larger %eV was obtained with high infusion rates (P = 0.039). The median %eV in Groups 1, 2, and 3 were 57.7, 74.2, and 90.5%, respectively. With AMA occlusion, CT demonstrated duodenal enhancement at an infusion rate of 36mL/min, and the median %eV in Groups 4, 5, and 6 were 92.8, 95.4, and 98.5%, respectively. A significantly larger %eV was obtained after AMA occlusion (P = 0.031). A higher infusion rate or AMA occlusion increases the enhanced volume in PIPP in pig models. No level of evidence.