Proximal Vein Research Articles

Severe Iron Deficiency Anemia Leading to Thrombocytosis With Arterial and Venous Thrombosis

A 45-year-old female who was a teacher by profession with a history of chronic asymptomatic anemia in the past presented to our hospital with complaints of intermittent fever for two weeks, cough with expectoration, dyspnea on exertion, and left upper limb edema for four days. She had a history of abdominal pain after food intake. She gave a history of having anemia for the past 23 years. Evaluation after admission showed raised inflammatory markers, marked thrombocytosis, and severe iron deficiency anemia. Further imaging in the form of a CT of the abdomen and thorax showed that she had a left-sided pleural effusion which showed an exudative picture, splenomegaly with a splenic infarct with a splenic abscess, and a suprarenal abdominal aorta thrombus. She was also found to have deep vein thrombosis (DVT) of the left subclavian and proximal internal jugular vein in a ultrasonogram (USG) Doppler. The workup done ruled out congenital and acquired causes of thrombosis and after extensive evaluation the patient was found to have unexplained thrombosis. The cause of unexplained thrombosis is the point of interest in this patient. Despite extensive workup, no precise cause for thrombosis, which was both arterial and venous in nature could be found out initially. Hence by exclusion, the possibility of secondary thrombocytosis causing the thrombosis was considered. Over the next few years, this patient underwent repeat esophageal endoscopies, colonoscopies, and capsule studies all without being able to pinpoint a diagnosis. Eventually three years later, a CT enteroscopy with biopsy showed the diagnosis of Crohn’s disease and the patient was started on appropriate immunosuppressive treatment for the same. There have been multiple case reports of thrombocytosis causing arterial or venous thrombus but not many have recorded both arterial and venous thrombosis in the same patient.

Endovenous microfoam ablation of below knee superficial truncal veins is safe and effective in patients with prior saphenous treatment across a wide range of CEAP classes

ObjectivePatients requiring thermal or chemical ablation of below knee (BK) truncal veins often have their proximal saphenous veins treated initially and comprise a study population with multilevel, refractory chronic venous insufficiency. The study objective was to assess the outcomes after microfoam ablation of BK truncal and tributary veins in patients with a history of proximal great saphenous vein (GSV) ablation or stripping. MethodsA retrospective review of a prospectively maintained database was performed. All the patients who had undergone endovenous chemical ablation with commercially manufactured polidocanol microfoam for symptomatic BK truncal vein reflux after a previous saphenous ablation or stripping were identified. The patients had undergone duplex ultrasound scanning 48 to 72 hours after the procedure; those who had not adhered to the recommended follow-up protocol were excluded. The demographic data, CEAP (clinical, etiologic, anatomic, pathophysiologic) classification, venous clinical severity score (VCSS), procedure details, adverse thrombotic events, and follow-up data were abstracted. ResultsBetween April 2018 and April 2021, 201 limbs were treated for symptomatic superficial truncal vein reflux with microfoam ablation. Of the 201 limbs, 68 in 49 patients met the inclusion criteria for the present study. The veins treated included the BK GSV (n = 45) and small saphenous vein (n = 23). The median follow-up was 97 days (range, 33-457 days) for the entire cohort. Most patients (63%) had a preoperative CEAP classification of C4 to C6. The median preoperative VCSS was 12.5. All the limbs that had undergone microfoam ablation in this cohort had a previously treated proximal ipsilateral GSV, with either thermal ablation or stripping. The median postoperative VCSS after BK treatment decreased to 10 (P < .001). The closure rate at the last follow-up was 96%. The overall symptomatic relief was 78% at the last follow-up. The absolute ulcer healing rate during the study period was 64% (16 of 25 ulcers had healed). One patient had developed thrombus extension into the popliteal vein, which resolved with anticoagulation therapy. One asymptomatic patient had developed nonocclusive thrombus in a gastrocnemius vein after small saphenous vein ablation. Because she was asymptomatic, anticoagulation therapy was not prescribed. Postoperative pain, phlebitis, and swelling were reported in 12%, 12%, and 2% of patients, respectively, and all had resolved at the last follow-up visit. Three limbs treated with chronic oral anticoagulant agents had had recanalized truncal veins during the study period after initial closure. No pulmonary emboli or neurologic adverse events were reported. No symptoms of saphenous or sural nerve injury had occurred. ConclusionsEndovenous chemical ablation with commercially manufactured polidocanol microfoam of BK truncal veins is a safe and effective treatment for patients with severe, refractory chronic venous insufficiency and prior saphenous interventions. This technique results in excellent overall closure rates and symptomatic relief with low adverse venous thrombotic events, across a wide range of CEAP classes.

Anatomical consideration of deep calf veins: application to catheter-directed thrombolysis.

PurposeAn antegrade approach is frequently used in catheter-directed thrombolysis to remove deep-vein thrombosis. However, the antegrade approach is difficult when accessing veins with small diameters; therefore, understanding the variation of deep calf vein is important.MethodsThis study measured the diameters and surface areas of the proximal and distal posterior tibial vein, peroneal vein, and anterior tibial vein to determine which are preferable for venous access. This study dissected 132 legs from Korean and Thai cadavers. The proximal and distal posterior tibial vein, peroneal vein, and anterior tibial vein were scanned and measured.ResultsThe mean diameter and surface area were largest for the proximal tibial vein, at 6.34 mm and 0.312 cm2, respectively, followed by the anterior tibial vein (5.22 mm and 0.213 cm2), distal posterior tibial vein (3.29 mm and 0.091 cm2), and peroneal vein (3.43 mm and 0.081 cm2). The proximal posterior tibial vein and anterior tibial vein have large diameters and surface areas, which make them ideal for applying an antegrade approach in catheter-directed thrombolysis.ConclusionsThe distal posterior tibial vein and peroneal vein are not recommended due to their smaller surface areas and also the anatomical variations therein.

Pancreatic-Portal Vein Fistula: a Rare Diagnosis with Wide-Ranging Complications—13-Year Experience of a Pancreas Center of Excellence

PurposeTo determine factors affecting mortality, and long-term patency of portal vein, in patients with pancreatic-portal vein fistula (PPVF). MethodsConsecutive cases of PPVF at the University of Pittsburgh Medical Center from 2008 to 2020 were retrospectively identified. Clinical history, imaging studies, management strategies, complications, and long-term outcomes were analyzed. ResultsFourteen patients, representing the largest PPVF cohort reported to date (mean age 58.6 years, 64.3% women, median follow-up 10 months [1–98 months]) were identified. Underlying chronic pancreatitis was seen in 9 (64.3%) patients, while 5 (35.7%) developed PPVF with first attack of acute pancreatitis. PPVF involved proximal main portal vein (MPV) in 10 (78.6%) patients. Of the 5 patients (35.7%) who died, all had occlusive (n=4) or near-occlusive (n=1) PPVF-associated filling defect (FD) in the MPV. Conversely, 7 of 9 survivors (87.5%) had subocclusive FD and patent MPV. In patients with sepsis (n=5), 1 underwent surgical necrosectomy and survived, while 3 of 4 (75%) patients without debridement died. ConclusionOcclusive/near-occlusive PPVF-associated MPV FD, and sepsis, are associated with high mortality rates, while subocclusive MPV FD is associated with survival and long-term MPV patency. PPVF is a potentially life-threatening, and possibly under-diagnosed, entity that warrants early clinical suspicion for timely diagnosis, to facilitate optimal management.

Risk factors for venous thromboembolism in patients with diabetes undergoing joint arthroplasty

BackgroundVenous thromboembolism (VTE) is a significant complication after joint arthroplasty. Diabetes is related to a few changes in coagulation and fibrinolysis that may lead to thrombophilia. We aimed to investigate the incidence of postoperative VTE and associated risk factors among patients with diabetes undergoing total hip (THA) or total knee anthroplasty (TKA) in a single centre in China.MethodsPatients with diabetes who underwent THA or TKA from January 2016 to December 2018 (n = 400) at Beijing Jishuitan Hospital were recruited in this study. Lower limb venous Doppler ultrasound was performed before and after surgery to confirm deep venous thrombosis (DVT). Computer tomography pulmonary angiography was done to confirm pulmonary embolism (PE) for those with new postoperative DVT and typical symptoms of PE. A multivariate logistic regression model was conducted to examine factors associated with the development of postoperative VTE.ResultsThe overall incidence of postoperative VTE in patients with diabetes after THA or TKA was 46.8 % (187 out of 400). Among the 187 VTE patients, 7.5 % (14 out of 187) had proximal vein thrombosis and 92.5 % (173 out of 187) had distal vein thrombosis. No PE occurred. Female patients and patients undergoing TKA had higher incidence of postoperative VTE. Patients who developed postoperative VTE were older, and had higher levels of preoperative D-Dimer and Caprini score. A high level of preoperative D-dimer (OR = 2.11, 95 %CI = 1.35–3.30) and the surgery of TKA (OR = 2.29, 95 %CI = 1.29–4.01) significantly increased the risk of developing postoperative VTE. Postoperative initiation of concomitant mechanical prophylaxis and low molecular weight heparin (LMWH) was protective for postoperative VTE (OR = 0.56, 95 %CI = 0.37–0.86).ConclusionsVTE is common in patients with diabetes undergoing joint arthroplasty. Patients undergoing TKA or with a high level of preoperative D-dimer are at a considerable risk of developing postoperative VTE. There may be a protective role of postoperative initiation of concomitant mechanical prophylaxis and LMWH for VTE.

The potential of closed-loop endovascular neurostimulation as a viable therapeutic approach for drug-resistant epilepsy: A critical review.

Over the last few decades, biomedical implants have successfully delivered therapeutic electrical stimulation to reduce the frequency and severity of seizures in people with drug-resistant epilepsy. However, neurostimulation approaches require invasive surgery to implant stimulating electrodes, and surgical, medical, and hardware complications are not uncommon. An endovascular approach provides a potentially safer and less invasive surgical alternative. This article critically evaluates the feasibility of endovascular closed-loop neuromodulation for the treatment of epilepsy. By reviewing literature that reported the impact of direct electrical stimulation to reduce the frequency of epileptic seizures, we identified clinically validated extracranial, cortical, and deep cortical neural targets. We identified veins in close proximity to these targets and evaluated the potential of delivering an endovascular implant to these veins based on their diameter. We then compared the risks and benefits of existing technology to describe a benchmark of clinical safety and efficacy that would need to be achieved for endovascular neuromodulation to provide therapeutic benefit. For the majority of brain regions that have been clinically demonstrated to reduce seizure occurrence in response to delivered electrical stimulation, vessels of appropriate diameter for delivery of an endovascular electrode to these regions could be achieved. This includes delivery to the vagus nerve via the 13.2±0.9mm diameter internal jugular vein, the motor cortex via the 6.5±1.7mm diameter superior sagittal sinus, and the cerebellum via the 7.7±1.4mm diameter sigmoid sinus or 6.2±1.4mm diameter transverse sinus. Deep cerebral targets can also be accessed with an endovascular approach, with the 1.9±0.5mm diameter internal cerebral vein and 1.2-mm-diameter thalamostriate vein lying in close proximity to the anterior and centromedian nuclei of the thalamus, respectively. This work identified numerous veins that are in close proximity to conventional stimulation targets that are of a diameter large enough for delivery and deployment of an endovascular electrode array, supporting future work to assess clinical efficacy and chronic safety of an endovascular approach to deliver therapeutic neurostimulation.

A systematic review on long-term clinical impact in patients with iliofemoral deep vein thrombosis.

The aim of this systematic review was to investigate the long-term clinical impact of iliofemoral (IF) deep vein thrombosis (DVT) based on patient reported outcomes, physician administered test measures and compare medical to interventional treatment. This study was conducted according to the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines. Criteria for inclusion were patients with thrombus involving the common femoral vein or more proximal veins, ≥5-year follow-up and physician assessment. Data quality was assessed using the Robins-I tool and Cochrane tool. Eight studies that fulfilled our criteria were deemed eligible and provided data for 499 patients. There were 230 patients who received medical treatment and 269 interventional. Two studies were randomized controlled trials and six observational. Venous claudication, where reported, was found in 7.7% (1/13) of interventionally treated patients and 21% (13/62) of medically treated patients. Long term symptom resolution was reported in 58% (18/31) and 24% (12/50) of interventionally and medically treated patients, respectively. Venous ulcers were seen in 5.5% (7/126) of medically treated patients and 5% (5/100)of interventionally treated patients. A wide range of signs and symptoms was reported at long-term. Interventional treatment appeared to be better than medical one but the evidence was weak. Given the significant lack of patient reported outcomes, objective testing and use of validated instruments, the results should be interpreted in context with these limitations. Data on long-term outcomes after IF DVT have been poorly reported and outcome criteria should be better defined in future studies.

State of the Art: Venous Causes of Pulsatile Tinnitus and Diagnostic Considerations Guiding Endovascular Therapy.

Venous variants and pathologic abnormalities are the most common causes of pulsatile tinnitus. These conditions include causes of turbulence within normally located veins and sinuses, and abnormally enlarged or abnormally located veins in close transmissive proximity to the conductive auditory pathway. Such disorders include pathologic abnormalities of the lateral sinus (transverse sinus stenosis and sigmoid sinus wall anomalies), abnormalities and variants of the emissary veins, and anomalies of the jugular bulb and jugular vein. Despite being the most common causes for pulsatile tinnitus, venous variants and pathologic abnormalities are often overlooked in the workup of pulsatile tinnitus. Such oversights can result in delayed patient care and prolonged patient discomfort. Advances in both cerebrovascular imaging and endovascular techniques allow for improved diagnostic accuracy and an increasing range of endovascular therapeutic options to address pulsatile tinnitus. This review illustrates the venous causes of pulsatile tinnitus and demonstrates the associated endovascular treatment. © RSNA, 2021.

Prevalence of Preoperative Lower Extremity Deep Vein Thrombosis in Bilateral Calcaneal Fractures

There are no studies on epidemiologic characteristics of deep vein thrombosis (DVT), when specified at in patients with bilateral calcaneal fractures. This study aimed to address the preoperative DVT in bilateral calcaneal fractures. Between October 2014 and December 2018, adult patients presenting with bilateral calcaneal fractures and having preoperative Duplex ultrasound (DUS) of bilateral lower extremities for detection of DVT were included. Their medical data were collected, with regards to demographics, comorbidities, injury-related data and biomarkers. Baseline characteristics between patients with and without DVT were compared using bivariate tests. The further multivariate logistics regression analysis was conducted to identify independent factors associated with DVT. In total, 258 patients with bilateral calcaneal fractures were included, with 21 (8.1%) having preoperative DVT, diagnosed at 7.7 ± 4.2 days after injury. The prevalence rate of proximal DVT was 1.9% and of distal DVT was 6.2%. Thirty five thrombi were found, with 6 (17.1%) in proximal veins and 29 (82.9%) in distal veins. Nine patients had DVTs in multiple veins, and 2 patients had bilateral DVTs. The multivariate analyses showed history of allergy (odds ratio [OR] = 2.17), concurrent other fractures (OR = 4.53), prolonged time since injury (for each day, OR = 1.16), elevated plasma D-dimer level (≥1.73 vs <1.73 mg/L, OR = 3.74) and reduced albumin level (<34.2 g/L vs ≥34.2 g/L, OR = 2.92) were independent factors associated with DVT. Multiple factors were identified to be associated with DVT and greater consideration should be given to the use of pharmacologic prophylaxis in patients involving these factors, to reduce DVT occurrence.

Chapter 5 Scottish mineral Geological Conservation Review sites – Hydrothermal veins and mineral assemblages

This fifth paper on Scottish mineral Geological Conservation Review (GCR) sites details those of highest conservation value for hydrothermal veins and associated mineral assemblages. The GCR sites are both large and small reflecting variations in past economic mining and extraction history. During the long mining histories, and after, the sites have yielded new mineral species and a new metal. From the largest ore field for lead, zinc and copper 80 or so minerals have been recognised, including nine new species, one of which was established as the first sulphite, scotlandite. Elsewhere gold and silver were also extracted. For some veins the country rocks were analysed to determine whether they provided the vein elements for primary and secondary minerals, and sometimes dated. Two sites exhibit polymetallic mineralisation, i.e., five elements in the mineral assemblages. In one site veins in close proximity to a sanukitoid pluton received signature elements from the intrusion. Veins in various areas formed in faults, fractures and shears which became conduits for ground waters reacting with vein minerals. Oxygen in the water reacted with lead, zinc and copper minerals and in the presence of CO2 and SO4 supergene mineral assemblages formed in appropriate alkalinities. It is therefore possible to establish paragenetic sequences and calculate stability fields for specific assemblages. Alkalinities and formation temperatures may also be obtained through fluid inclusions studies and isotope analysis.

Application of Proximal Splenic Vein Embolization to Interrupt Complicated Large Splenorenal Shunts in Adult Living Donor Liver Transplantation.

The aim of the present study is to evaluate efficacy and safety of proximal splenic vein embolization (PSVE) for liver transplant recipients having complicated large splenorenal shunts (SRS). In adult living donor liver transplantation for a patient who has large splenorenal shunts (SRS), their interruption is utmost important to maintain adequate portal flow by avoidance of portal flow steal through the preexisting SRS. We effectively managed most of the recipients with surgical ligation and/or additional radiologic embolization using by intraoperative cine-portogram. However, when complete interruption is not achieved in a few recipients having complicated large SRS, it may leave a chance of lethal portal flow steal in the recipient afterward. PSVE was performed in 13 patients between April 2014 and November 2017. We performed a retrospective analysis of preoperative images, postoperative graft and recipient outcomes, and presence of isolated portal hypertension. Ten patients underwent PSVE as an additional secondary method because of portal steal syndrome through the remaining SRS after surgical interruption and/or embolization, and 3 patients underwent PSVE only as a primary method of SRS interruption. In all 13 patients, portal steal on the final intraoperative cine-portogram completely disappeared after PSVE. All patients recovered with satisfactory regeneration of the partial liver graft without the reappearance of portosystemic collaterals, and there were no procedure-related complications. PSVE is an effective and safe procedure to secure adequate portal flow without portal steal for patients with complicated large SRS arising from multiple sites of the splenic vein or escaping to multiple terminal ends.

Constraints on the timing and genetic link of scheelite- and wolframite-bearing quartz veins in the chuankou W ore field, South China

• LA-ICP-MS zircon analysis confirms age of ~237–227 Ma of the Granitic intrusion. • Diverse W deposit type in Chuankou shows accordant mineralization age. • Late Triassic W mineralization and magmatism are recognized. • Undiscovered granite in the deep part is associated to W mineralization. The Chuankou W ore field, located in the Nanling region, South China, is one of the famous W ore fields in China, which displays many of the metallogenic features commonly associated with granitic intrusion, including vein type scheelite and wolframite mineralization. The Chuankou W deposit is the most important deposit in the Chuankou ore field. The diverse W mineralization around the Chuankou pluton exhibits orderly zoning and comprises proximal wolframite-bearing quartz veins and distal scheelite-bearing quartz veins. The scheelite-bearing quartz veins occur invariably in sandstone and slate, whereas the wolframite-bearing veins are mainly hosted by the granite. Medium-grained muscovite granite exposed to the surface, while the hidden granite pluton in tunnel is mainly composed of fine-grained tourmaline-bearing granite. In situ zircon and hydrothermal wolframite U–Pb dating and molybdenite Re–Os dating techniques are used to refine the age spectra of granitic intrusion and W mineralization in the Chuankou area. Medium-grained muscovite granite and fine-grained tourmaline-bearing granite of the Chuankou granitic intrusion have zircon U–Pb ages of 237 Ma and 227 Ma, respectively. The molybdenite Re–Os age of the scheelite-bearing quartz veins is 212.5 ± 7.3 Ma, which is consistent with the U–Pb age of the hydrothermal wolframite from wolframite-bearing quartz vein (212.6 ± 1.4 Ma). The combined chronology data collectively indicate that the two types of W mineralization have a temporal and genetic link. Our new magmatism and mineralization dates in the Chuankou deposit demonstrated that Nanling region has an enormous potential for Indosinian W mineralization and more attention should be given to the Indosinian ore prospecting in the region. These similar ore-forming ages demonstrate that the W mineralization type may be controlled by the lithologies of wall-rock which can provide Ca for scheelite and Fe/Mn for wolframite. The two mineralization ages are significantly inconsistent with the zircon U–Pb age of the Chuankou pluton, which may indicate that granite only plays a wall rock role in the formation of wolframite-bearing quartz veins. The W mineralization in the Chuankou is interpreted to be genetically related to a hidden Late Triassic granitic pluton. By studies of the high-precision geochronological, the genetic model of the W mineralization of the Chuankou deposit precludes genetic link between the W mineralization and Chuankou pluton and predicts a metallogenic granite in the deep part of Chuankou pluton have not been exposed.

The thrombosis of a 13 years old aneurysmal arteriovenous fistula

A 46 years old female, with chronic stage renal failure for 15 years, presents to the emergency room with a thrombosis of her brachiocephalic arteriovenous fistula (functional for 13 years). The cephalic vein was aneurismal (6cm diameter) and the brachial artery was not dilated. After proximal and distal control of the brachial artery and the proximal cephalic vein, the aneurismal arteriovenous fistula was excise, the cephalic vein was ligatured, and the brachial artery was repaired with an end to end anastomosis.

The Carotid Endarterectomy Cadaveric Investigation for Cranial Nerve Injuries: Anatomical Study.

Cerebral stroke continues to be one of the leading causes of mortality and long-term morbidity; therefore, carotid endarterectomy (CEA) remains to be a popular treatment for both symptomatic and asymptomatic patients with carotid stenosis. Cranial nerve injuries remain one of the major contributor to the postoperative morbidities. Anatomical dissections were carried out on 44 sides of 22 cadaveric heads following the classical CEA procedure to investigate the variations of the local anatomy as a contributing factor to cranial nerve injuries. Concurrence of two variations was found to be important in hypoglossal nerve injury: the presence of a direct smaller vein in proximity of the carotid bifurcation, and the intersection of the hypoglossal nerve (HN) with this vein. Based on the sample investigated, this variation was observed significantly higher on the right side. Awareness of possible anatomical variations and early ligation of any small veins can significantly decrease iatrogenic injury risk.

Incidence and risk factors predicting deep venous thrombosis of lower extremity following spinal fractures

The aim of this study was to investigate the presence of preoperative DVT following spinal fracture and the association between the presence of DVT and risk factors. Ultrasonography and blood analyses were performed preoperatively in patients diagnosed with spinal fracture between October 2014 and December 2018. Univariate analyses were performed on the data of demographics, comorbidities, location of injury, spinal cord injury (SCI) grading and laboratory biomarkers. The receiver operating characteristic (ROC) curve analysis was employed to obtain the optimal D-dimer cut-off value for diagnosis. In total, 2432 patients with spinal fractures were included, among whom 108 (4.4%) patients had preoperative DVTs. The average interval between fracture and initial diagnosis of DVT was 4.7 days (median, 2 days), ranging from 0 to 20 days; 78 (72.2%) were diagnosed within 7 days after injury and 67 (62.0%) within 3 days; 19 (17.5%) patients had proximal vein involved and 89 (82.4%) presented in distal veins. Multivariate logistic regression suggested six risk factors independently correlated to DVT, including delay to DUS (in each day) (odds ratio [OR] = 1.11), ASA class III–IV (OR = 2.36), ASIA grade (A/B) (OR = 2.36), ALB < 3.5 g/dL (OR = 2.08), HDL-C < 1.1 mmol/L (OR = 1.68) and d-Dimer > 1.08 µg/ml (OR = 2.49).

RENAL VEIN THROMBOSIS AT HIGH ALTITUDE

Though risk of venous thromboembolism in increased at high altitude, involvement of renal veins is rare. A 27-year-old soldier was evacuated from a height of 18000 feet after developing flank pain and haematuria. Ultrasound showed an enlarged left kidney and lack of flow in proximal renal vein. CT scan confirmed the presence of renal vein thrombus. Serum IgM Anti β-2 Glycoprotein I antibodies, IgG Anti β-2 Glycoprotein I antibodies and IgM anticardiolipin antibodies were detectable and the former two were present after three months also. Secondary causes of antiphospholipid syndrome were excluded. He was started on low molecular weight heparin and is now on lifelong oral anticoagulation with warfarin.

Pathophysiological Processes Underlying the High Prevalence of Deep Vein Thrombosis in Critically Ill COVID-19 Patients.

Coronavirus disease 2019 (COVID-19) predisposes to deep vein thrombosis (DVT) and pulmonary embolism (PE) particularly in mechanically ventilated adults with severe pneumonia. The extremely high prevalence of DVT in the COVID-19 patients hospitalized in the intensive care unit (ICU) has been established between 25 and 84% based on studies including systematic duplex ultrasound of the lower limbs when prophylactic anticoagulation was systematically administrated. DVT prevalence has been shown to be markedly higher than in mechanically ventilated influenza patients (6–8%). Unusually high inflammatory and prothrombotic phenotype represents a striking feature of COVID-19 patients, as reflected by markedly elevated reactive protein C, fibrinogen, interleukin 6, von Willebrand factor, and factor VIII. Moreover, in critically ill patients, venous stasis has been associated with the prothrombotic phenotype attributed to COVID-19, which increases the risk of thrombosis. Venous stasis results among others from immobilization under muscular paralysis, mechanical ventilation with high positive end-expiratory pressure, and pulmonary microvascular network injuries or occlusions. Venous return to the heart is subsequently decreased with increase in central and peripheral venous pressures, marked proximal and distal veins dilation, and drops in venous blood flow velocities, leading to a spontaneous contrast “sludge pattern” in veins considered as prothrombotic. Together with endothelial lesions and hypercoagulability status, venous stasis completes the Virchow triad and considerably increases the prevalence of DVT and PE in critically ill COVID-19 patients, therefore raising questions regarding the optimal doses for thromboprophylaxis during ICU stay.

Two-point compression ultrasonography: Enough to rule out lower extremity deep venous thrombosis?

Deep venous thrombosis (DVT) is a major cause of morbidity and is a common presenting complaint to the emergency department (ED). Point-of-care two-point compression ultrasonography has evolved as a quick and effective way of diagnosing DVT. The purpose of this study is to validate the prevalence and distribution of venous thrombi isolated to proximal lower extremity veins, other than common femoral and popliteal veins in patients with DVT. This is a single-center retrospective study that looked at patients presenting to the ED of a tertiary care hospital between January 2014 and August 2018. The clinical presentation and laboratory and imaging results were obtained using the hospital's electronic medical record. A total of 2,507 patients underwent a lower extremity duplex ultrasound during the study period. Among them, 379 (15%) were included in the study. The percentages of isolated thrombi to the femoral vein and deep femoral vein were 7.92% and 0.53%, respectively. When the patients were stratified into the two groups of isolated DVT and two-point compression DVT, there were no statistically significant differences in the laboratory results between both groups. However, immobilized patients and patients with recent surgeries were more likely to have an isolated DVT. Thrombi isolated to proximal lower extremity veins other than the common femoral and popliteal veins make up 8.45% of DVTs. Given this significant number of missed DVTs, the authors recommend the addition of the femoral and deep femoral veins to the two-point compression exam.

Complex reconstruction of arteriovenous fistula for hemodialysis

We report a complex reconstruction of arteriovenous fistula (AVF). Proximal stenosis of cephalic vein was followed by aneurysms of fistulous veins (distal segment of cephalic vein and median cubital vein) complicated by AVF thrombosis. Blood outflow from AVF was retrograde. One week after thrombosis, an aneurysm of median cubital vein containing dense clots was excised. We resected cephalic vein wall and repaired the vessel. Anastomosis with the brachial artery was created distal to the last anastomosis. Proximal cephalic vein repair was performed using resected aneurysm walls. After a year, AVF has been successfully used for hemodialysis.

Splenic vessels first approach laparoscopic spleen-preserving distal pancreatectomy with kimura technique (with short video clip)

Aim: In order to improve the success rate of spleen preservation in laparoscopic distal pancreatectomy with Kimura technique, we use a new splenic vessels control procedure which we call splenic vessels first approach. Method: We begin the operation with dividing the gastrosplenic ligament in order to expose the body and tail of the pancreas. We are now dissecting out the splenic artery first. With opening the capsule of the superior border of the pancreas, here the splenic artery comes into view. The proximal splenic artery is blocked with a bulldog. The next step wiil be distal splenic vein mobilization and blockage. We dissect at left side of the inferior border of the pancreas tail near the splenic hilus and block the distal splenic vein with another bulldog. After fully blocking the proximal splenic artery and distal splenic vein, we perform laparoscopic spleen-preserving distal pancreatectomy with standard Kimura technique. Result: With fully controlling the inflow of splenic artery and outflow of distal splenic vein , the distal pancrease is easy dissected with the splenic vessels presevation. We have successfully fulfilled all 10 cases of laparoscopic spleen-preserving distal pancreatectomy with Kimura technique. No postoperative splenic complications such as splenic infarction and abscess have been founded by far. Conclusions: Splenic vessels first approach laparoscopic spleen-preserving distal pancreatectomy is a safe procedure and offers technique advantages of lesser blood loss, operation time spare and higher success rate of spleen preservation over the conventional Kimura technique, while no extra postoperative morbidity founded.