Vessel segmentation from abdominal magnetic resonance images: adaptive and reconstructive approach

The liver vessels, which have low signal and run next to brighter bile ducts, are difficult to segment from MR images. This study presents a fully automated and adaptive method to segment portal and hepatic veins on magnetic resonance images. In the proposed approach, segmentation of these vessels is achieved in four stages: (i) initial segmentation, (ii) refinement, (iii) reconstruction, and (iv) post-processing. In the initial segmentation stage, k-means clustering is used, the results of which are refined iteratively with linear contrast stretching algorithm in the next stage, generating a mask image. In the reconstruction stage, vessel regions are reconstructed with the marker image from the first stage and the mask image from the second stage. Experimental data sets include slices that show fat tissues, which have the same gray level values with vessels, outside the margin of the liver. These structures are removed in the last stage. Results show that the proposed approach is more efficient than other thresholding-based methods. Copyright © 2016 John Wiley & Sons, Ltd.

Hemodynamic pathways of gestational hypertension and preeclampsia

Gestational hypertension and preeclampsia are the 2 main types of hypertensive disorders in pregnancy. Noninvasive maternal cardiovascular function assessment, which helps obtain information from all the components of circulation, has shown that venous hemodynamic dysfunction is a feature of preeclampsia but not of gestational hypertension. Venous congestion is a known cause of organ dysfunction, but its potential role in the pathophysiology of preeclampsia is currently poorly investigated. Body water volume expansion occurs in both gestational hypertension and preeclampsia, and this is associated with the common feature of new-onset hypertension after 20 weeks of gestation. Blood pressure, by definition, is the product of intravascular volume load and vascular resistance (Ohm's law). Fundamentally, hypertension may present as a spectrum of cardiovascular states varying between 2 extremes: one with a predominance of raised cardiac output and the other with a predominance of increased total peripheral resistance. In clinical practice, however, this bipolar nature of hypertension is rarely considered, despite the important implications for screening, prevention, management, and monitoring of disease. This review summarizes the evidence of type-specific hemodynamic profiles in the latent and clinical stages of hypertensive disorders in pregnancy. Gestational volume expansion superimposed on an early gestational closed circulatory circuit in a pressure- or volume-overloaded condition predisposes a patient to the gradual deterioration of overall circulatory function, finally presenting as gestational hypertension or preeclampsia-the latter when venous dysfunction is involved. The eventual phenotype of hypertensive disorder is already predictable from early gestation onward, on the condition of including information from all the major components of circulation into the maternal cardiovascular assessment: the heart, central and peripheral arteries, conductive and capacitance veins, and body water content. The relevance of this approach, outlined in this review, openly invites for more in-depth research into the fundamental hemodynamics of gestational hypertensive disorders, not only from the perspective of the physiologist or the scientist, but also in assistance of clinicians toward understanding and managing effectively these severe complications of pregnancy.

Systematic examination of the fetal abdominal precordial veins: a cohort study

OBJECTIVES

Examination of the fetal venous system is a necessary part of complete fetal organ scanning to confirm landmark anatomy, such as the ductus venosus and course of the umbilical veins, and, whenever cardiovascular anomalies are identified, to exclude associated anomalous development of the fetal veins. We aimed to develop a protocol for systematic examination of the fetal venous system during midtrimester targeted organ scanning.

METHODS

We included low-risk women with a singleton fetus presenting between January 2011 and June 2013 to our center for routine midtrimester (20-24 weeks) targeted organ scanning. Imaging of the venous system was added to the booked scan and comprised two-dimensional color Doppler scanning of the fetal abdomen in three discrete planes, two transverse and one longitudinal. The more caudal plane was obtained in a ventral or lateral transverse abdominal plane to image the umbilical vein, left portal vein, portal sinus, anterior right portal vein, posterior right portal vein, main portal vein and splenic vein and artery. Moving cephalad, a ventral or lateral transverse plane was obtained to image the right, middle and left hepatic veins and inferior vena cava (IVC). Finally, a longitudinal anteroposterior plane showed the umbilical vein, ductus venosus, IVC and left hepatic vein. In some cases the pulsed Doppler waveform of a given target vessel was also examined. Three-dimensional/4D ultrasound was applied as necessary, when anomalous cases were encountered.

RESULTS

We examined 1810 women. Their body mass index ranged from 19 to 40 (mean, 24.7). In 38 (2.1%) women, the target anatomy was not visualized satisfactorily owing to maternal body habitus. A T-shaped configuration of the portal system vessels was observed in 63% of cases, an X-shaped configuration in 25% and an H-shaped configuration in 12%. During the study period, 24 congenital anomalies of the precordial venous system were diagnosed: nine cases of persistent right umbilical vein, seven of agenesis of the ductus venosus, five of anomalous portal venous drainage and three of interrupted IVC with azygos continuation.

CONCLUSIONS

Examination of the fetal venous system is feasible with the application of three abdominal planes. While a venous system scan is not practicable as part of a screening-level examination, mastery of the normal anatomy is an essential part of the professional knowledge base, in order to provide ready and complete scanning of the system in cases of suspected anomalies or disordered cardiac function.

The Influence of Respiration on Blood Flow in the Fontan Circulation: Insights for Imaging-Based Clinical Evaluation of the Total Cavopulmonary Connection

Congenital heart disease is the most common birth defect and functionally univentricular heart defects represent the most severe end of this spectrum. The Fontan circulation provides an unique solution for single ventricle patients, by connecting both caval veins directly to the pulmonary arteries. As a result, the pulmonary circulation in Fontan palliated patients is characterized by a passive, low-energy circulation that depends on increased systemic venous pressure to drive blood toward the lungs. The absence of a subpulmonary ventricle led to the widely believed concept that respiration, by sucking blood to the pulmonary circulation during inspiration, is of great importance as a driving force for antegrade blood flow in Fontan patients. However, recent studies show that respiration influences pulsatility, but has a limited effect on net forward flow in the Fontan circulation. Importantly, since MRI examination is recommended every 2 years in Fontan patients, clinicians should be aware that most conventional MRI flow sequences do not capture the pulsatility of the blood flow as a result of the respiration. In this review, the unique flow dynamics influenced by the cardiac and respiratory cycle at multiple locations within the Fontan circulation is discussed. The impact of (not) incorporating respiration in different MRI flow sequences on the interpretation of clinical flow parameters will be covered. Finally, the influence of incorporating respiration in advanced computational fluid dynamic modeling will be outlined.

Management of portal hypertension and ascites in polycystic liver disease

Patients suffering from polycystic liver disease may develop Hepatic Venous Outflow Obstruction, Portal Vein Obstruction and/or Inferior Caval Vein Syndrome because of cystic mass effect. This can cause portal hypertension, leading to ascites, variceal haemorrhage or splenomegaly. For this review, we evaluate the evidence to provide clinical guidance for physicians faced with this complication. Diagnosis is made with imaging such as ultrasound, computed tomography or magnetic resonance imaging. Therapy includes conventional therapy with diuretics and paracentesis, and medical therapy using somatostatin analogues. Based on disease phenotype various (non-)surgical liver-volume reducing therapies, hepatic or portal venous stenting, transjugular intrahepatic portosystemic shunts and liver transplantation may be considered. Because of complicated anatomy, use of high-risk interventions and lack of empirical evidence, patients should be treated in expert centres.

What is a precise anatomic resection of the liver? Proposal of a new evaluation method in the era of fluorescence navigation surgery

BACKGROUND/PURPOSE

Indocyanine green (ICG) fluorescence navigation has been adapted for anatomic liver resection (AR) but an objective method for evaluation of its validity is required. This pilot study aimed to propose a new method to evaluate the accuracy of parenchymal division along the plane between hepatic segments and estimate the real-time navigation efficacy for AR by the Medical Imaging Projection System (MIPS), which continuously demonstrates the transection plane using projection mapping with ICG fluorescence.

METHODS

Ten patients who underwent open AR using liver segmentation with ICG fluorescence technique between August 2016 and July 2019 were included: six patients under MIPS guidance (MIPS group), while four using only conventional ICG fluorescence technique before parenchymal resection (non-MIPS group). Densitometry of the captured fluorescence image was performed to evaluate the fluorescence area ratio of each transection plane. The accurate fluorescence area ratio was calculated by subtracting the fluorescence area rate on the resected side from that on the remnant side.

RESULTS

The accurate fluorescence area ratio of the MIPS group and the non-MIPS group was 23.0 ± 12.6% and 5.6 ± 9.5%, respectively (P = .038).

CONCLUSIONS

Based on the results of our new method, real-time navigation using the MIPS may facilitate performing AR along the plane between hepatic segments.

Importance Rat Liver Morphology and Vasculature in Surgical Research

BACKGROUND The laboratory rat is one of the most popular experimental models for the experimental surgery of the liver. The objective of this study was to investigate the morphometric parameters, physiological data, differences in configuration of liver lobes, biliary system, and vasculature (arteries, veins, and lymphatic vessels) of the liver in laboratory rats. In addition, this study supports the anatomic literature and identified similarities and differences with human and other mammals. MATERIAL AND METHODS Forty laboratory rats were dissected to prepare corrosion casts of vascular system specimens (n=20), determine the lymph vessels and lymph nodes (n=10), and for macroscopic anatomical dissection (n=10) of the rat liver. The results are listed in percentages. The anatomical nomenclature of the liver morphology, its arteries, veins, lymph nodes, and lymphatic vessels are in accordance with Nomina Anatomica Veterinaria. RESULTS We found many variations in origin, direction, and division of the arterial, venous, and lymphatic systems in rat livers, and found differences in morphometric parameters compared to results reported by other authors. The portal vein was formed by 4 tributaries in 23%, by 3 branches in 64%, and by 2 tributaries in 13%. The liver lymph was drained to the 2 different lymph nodes. The nomenclature and morphological characteristics of the rat liver vary among authors. CONCLUSIONS Our results may be useful for the planing of experimental surgery and for cooperation with other investigation methods to help fight liver diseases in human populations.

A modified sequential vascular control strategy in robot-assisted level III-IV inferior vena cava thrombectomy: initial series mimicking the open 'milking' technique principle

OBJECTIVE

To introduce a modified sequential vascular control strategy, mimicking the open 'milking' technique principle, for the early release of the first porta hepatis (FPH) and to stop cardiopulmonary bypass (CPB) in level III-IV robot-assisted inferior vena cava (IVC) thrombectomy (RA-IVCTE).

PATIENTS AND METHODS

From November 2014 to June 2019, 27 patients with a level III-IV IVC tumour thrombus (IVCTT) underwent RA-IVCTE in our department. The modified sequential control strategy was used in 12 cases. Previously, we released the FPH after the thrombus was resected and the IVC was closed completely, and CPB was stopped at the end of surgery (15 patients). Presently, using our modified strategy, we place another tourniquet inferior to the second porta hepatis (SPH) once the proximal thrombus is removed from the IVC below the SPH. Then, we suture the right atrium and perform early release of the FPH, and stop CPB. Finally, tumour thrombectomy, vascular reconstruction, and radical nephrectomy are performed.

RESULTS

Compared with the previous strategy, the modified steps resulted in a shorter median FPH clamping (19 vs 47 min, P < 0.001) and CPB times (60 vs 87 min, P < 0.05); a lower rate of Grade II-IV perioperative complications (25% vs 60%, P < 0.05); and better postoperative hepatorenal and coagulation function, including better median serum alanine aminotransferase (172.7 vs 465.4 U/L, P < 0.001), aspartate aminotransferase (282.4 vs 759.8 U/L, P < 0.001), creatinine (113.4 vs 295 μmol/L, P < 0.01), blood urea nitrogen (7.3 vs 16.7 mmol/L, P < 0.01), and D-dimer (5.9 vs 20 mg/L, P < 0.001) levels.

CONCLUSION

With the early release of the FPH and stopping CPB, the modified sequential vascular control strategy in level III-IV RA-IVCTE reduced the perioperative risk for selected patients and improved the feasibility and safety of the surgery. We would recommend this approach to other centres that plan to develop robotic surgery for renal cell carcinoma with level III-IV IVCTT in the future.

Excellent long-term outcomes of endovascular treatment in budd-chiari syndrome with hepatic veins involvement: A STROBE-compliant article

This study aimed to evaluate the long-term efficacy and safety of percutaneous transhepatic balloon angioplasty (PTBA) and transjugular intrahepatic portosystemic stent-shunt (TIPSS) in the treatment of Budd-Chiari syndrome (BCS) with hepatic veins involvement. Between June 2008 and August 2016, a total of 60 BCS patients with hepatic vein involvement in our department were enrolled in this study. Thirty-three cases underwent hepatic vein balloon angioplasty in PTBA Group and 27 cases underwent TIPSS. Data were retrospectively collected, and follow-up observations were performed. TIPSS Group showed significantly higher thrombotic/segmental obstruction and peripheral stenosis/obstruction compared with PTBA Group. The success rates were 93.9% and 100.0% in PTBA Group and TIPSS Group, respectively. The mean portal vein pressure decreased significantly after stenting. Except for 1 patient died from repeated hemorrhage, other sever complications had not been observed in both group. Twenty-six patients and 21 patients were clinically cured in PTBA Group and TIPSS Group, respectively. The primary patency rates were 89.7%, 79.3%, and 79.3% for short-term, mid-term and longterm in PTBA Group, which were significantly higher than TIPSS Group for long-term follow up. The second patency rates were 100.0%, 96.6% and 96.6% for short-term, mid-term and long-term in PTBA Group, which were similar to TIPSS Group (P = 1.0000). In conclusion, PTBA and TIPSS are safe and effective in the treatment of BCS with hepatic veins involvement, with an excellent long-term patency rate of hepatic vein and TIPSS shunt. TIPSS can be used to treat patients with all 3 hepatic veins lesion and failure PTBA.

A randomized porcine study of the hemodynamic and metabolic effects of combined endovascular occlusion of the vena cava and the aorta in normovolemia and in hemorrhagic shock

BACKGROUND

Mortality from traumatic retrohepatic venous injuries is high and methods for temporary circulatory stabilization are needed. We investigated survival and hemodynamic and metabolic effects of resuscitative endovascular balloon occlusion of the aorta (REBOA) and vena cava inferior (REBOVC) in anesthetized pigs.

METHODS

Twenty-five anesthetized pigs in normovolemia or severe hemorrhagic shock (controlled arterial bleeding in blood bags targeting systolic arterial pressure of 50 mm Hg, corresponding to 40-50% of the blood volume) were randomized to REBOA zone 1 or REBOA+REBOVC zone 1 (n = 6-7/group) for 45 minutes occlusion, followed by 3-hour resuscitation and reperfusion. Hemodynamic and metabolic variables and markers of end-organ damage were measured regularly.

RESULTS

During occlusion, both the REBOA groups had higher systemic mean arterial pressure (MAP) and cardiac output (p < 0.05) compared with the two REBOA+REBOVC groups. After 60 minutes reperfusion, there were no statistically significant differences between the two REBOA groups and the two REBOA+REBOVC groups in MAP and cardiac output. The two REBOA+REBOVC groups had higher arterial lactate and potassium concentrations during reperfusion, compared with the two REBOA groups (p < 0.05). There was no major difference in end-organ damage markers between REBOA and REBOA+REBOVC. Survival after 1-hour reperfusion was 86% and 100%, respectively, in the normovolemic REBOA and REBOA+REBOVC groups, and 67% and 83%, respectively, in the corresponding hemorrhagic shock REBOA and REBOA+REBOVC groups.

CONCLUSION

Acceptable hemodynamic stability during occlusion and short-term survival can be achieved by REBOA+REBOVC with adequate resuscitation; however, the more severe hemodynamic and metabolic impacts of REBOA+REBOVC compared with REBOA must be considered.

LEVEL OF EVIDENCE

Prospective, randomized, experimental animal study. Basic science study, therapeutic.

Variations in the vascular and biliary structures of the liver: a comprehensive anatomical study

PURPOSE

Vascular structures of the liver and the bile ducts are crucial during liver transplantation or liver resection surgery. Here, we report on variations in the vascular structures and bile ducts of 200 patients.

MATERIALS AND METHODS

We reviewed magnetic resonance cholangiopancreatographic and multiple-detector computed tomographic data.

RESULTS

Michels type 1 was detected in 54% of the patients. The other most common variations were, respectively, Michels type 5 (13%) and type 2 (11%). Unclassified variations were defined as Michels type 11; 5% of patients were in this group. Type 1 variations in the hepatic portal vein were detected in 76% of our study group. Other common variations were type 2 (9%) and type 3 (8.5%). The left and intermediate hepatic veins united to become a single vein and then joined the inferior vena cava in 64% of the patients. The right, intermediate, and left hepatic veins joined the inferior vena cava separately in 36% of the patients. Type A, which represents the classic anatomy of the bile duct, was observed in 51.5% of our patients. Type C1 and type B were detected in 15% and 12% of patients, respectively.

CONCLUSIONS

We describe vascular and biliary variations in the livers of our patients.

Spectral Doppler of the Hepatic Veins in Rate, Rhythm, and Conduction Disorders

Doppler interrogation of blood flow in the hepatic veins (HVs) provides valuable information regarding a wide spectrum of pathological processes that affect the right heart. Systematic analysis of the direction, velocity, and phasicity of the HV waveforms allows one to distinguish normal from abnormal patterns and provides important diagnostic information. Abnormalities in heart rate, rhythm, and intracardiac conduction are commonly encountered during echocardiographic studies. Sinus bradycardia and tachycardia, bradyarrhythmias and tachyarrhythmias as well as atrioventricular conduction disturbances influence the flow pattern in the HVs and may pose a challenge to the correct interpretation of the HV Doppler. Alterations in HV flow that are induced by the electrical abnormalities may mimic right heart pathology. Awareness of these alterations allows one to avoid misinterpretation of the HV signal, helps diagnose the underlying rhythm or conduction abnormality, and permits assessment of the impact on right heart hemodynamics.

Periportal fields cause stronger cooling effects than veins in hepatic microwave ablation: an in vivo porcine study

BACKGROUND

Vascular cooling effects are a well-known source for tumor recurrence in thermal in situ ablation techniques for hepatic malignancies. Microwave ablation (MWA) is an ablation technique to be considered in the treatment of malignant liver tumors. The impact of vascular cooling in MWA is still controversial.

PURPOSE

To evaluate the influence of different intrahepatic vessel types, vessel sizes, and vessel-to-antenna-distances on MWA geometry in vivo.

MATERIAL AND METHODS

Five MWAs (902-928 MHz) were performed with an energy input of 24.0 kJ in three porcine livers in vivo. MWA lesions were cut into 2-mm slices. The minimum and maximum radius of the ablation area was measured for each slice. Distances were measured from ablation center toward all adjacent hepatic vessels with a diameter of ≥1 mm and within a perimeter of 20 mm around the antenna. The respective vascular cooling effect relative to the maximum ablation radius was calculated.

RESULTS

In total, 707 vessels (489 veins, 218 portal fields) were detected; 370 (76%) hepatic veins and 185 (85%) portal fields caused a cooling effect. Portal fields resulted in higher cooling effects (37%) than hepatic veins (26%, P < 0.01). No cooling effect could be observed in close proximity of vessels within the central ablation zone.

CONCLUSION

Hepatic vessels influenced MWA zones and caused a distinct cooling effect. Portal fields resulted in more pronounced cooling effect than hepatic veins. No cooling effect was observed around vessels situated within the central white zone.

Doppler Ultrasound of Vascular Complications After Pediatric Liver Transplantation: Incidence, Time of Detection, and Positive Predictive Value

Purpose Doppler ultrasound (DUS) is widely used to detect vascular complications after pediatric liver transplantation (LT). This study aimed to assess the moment of first detection of vascular complications with DUS, and to determine the positive predictive value (PPV) of DUS.

Materials and Methods Patients aged 0–18 years who underwent LT between 2015 and 2019 were retrospectively included. 92 LTs in 83 patients were included (median age: 3.9 years, interquartile range: 0.7–10.5). Patients underwent perioperative (intra-operative and immediately postoperative) and daily DUS surveillance during the first postoperative week, and at 1, 3, and 12 months. Vascular complications were categorized for the hepatic artery, portal vein, and hepatic veins. DUS findings were compared to surgical or radiological findings during the 1-year follow-up.

Results 52 vascular complications were diagnosed by DUS in 35/92 LTs (38%). 15 out of 52 (28.8%) were diagnosed perioperatively, 29/52 (55.8%) were diagnosed on postoperative days 1–7, and 8/52 (15.4%) after day 7. The PPV for all vascular complications diagnosed with DUS was 92.3%. During the 1-year follow-up, 18/19 (94.7%) hepatic artery complications, 19/26 (73.1%) portal vein complications, and 7/7 (100%) hepatic vein complications were diagnosed perioperatively or during the first week.

Conclusion The majority of vascular complications during the first year after pediatric LT were diagnosed by DUS perioperatively or during the first week, with a high PPV. Our findings provide important information regarding when to expect different types of vascular complications on DUS, which might improve DUS post-LT surveillance protocols.

Technical Intraoperative Maneuvers for the Management of Inferior Vena Cava Thrombus in Renal Cell Carcinoma

Introduction

Renal vein or inferior vena cava (IVC) invasion by neoplastic thrombus in patients with renal cell carcinoma (RCC) is not an obstacle for radical oncological treatment. The aim of this study is to present our technical maneuvers for complete removal of the intracaval thrombus without compromising hemodymanic stability of the patient.

Materials and methods

Between 2000 and 2014, 15 RCC patients with IVC involvement of levels I–III were treated with curative intent and were prospectively studied. The operative technique varied according to thrombus extent. For type I, extraction of the thrombus is facilitated by a 2–3 cm longitudinal incision on the IVC that begins at the level of the renal vein and extends cranially, encompassing a vessel wall rim of the orifice of the resected renal vein. For type II cases, the IVC is clamped above the neoplastic thrombus, and for type III, the IVC clamping is combined with hepatic blood flow control with “Pringle maneuver.” For type IV, the IVC is clamped above the diaphragm, or if the thrombus extends into the right atrium cardiothoracic input is appropriate.

Results

The main operative steps include preparation and control of the renal vessels and the IVC. Occasionally, for type III tumor thrombi, the patient becomes hemodynamically unstable when IVC is clamped suprahepatically. In such a case, a novel operative maneuver of milking the thrombus below the orifice of the hepatic veins, and subsequently the IVC clamp also beneath the hepatic veins, allowing release of the “Pringle maneuver” is performed. This operative step restores hepatic blood flow and hemodynamic stability and is based on the floating nature of the thrombus into the IVC. Mean operative time was 120 min (range from 90 to 180 min), and average liver and renal warm ischemia time was 20 min (range from 15 to 35 min). Postoperative overall hospital stay ranged from 7 to 13 days.

Conclusion

The technical solutions employed in the current study allow successful removal of neoplastic thrombi from the IVC in most cases, associated with minimal perioperative complication rate even for patients who due to multiple comorbidities would be considered otherwise inoperable.

Spectral Doppler of the Hepatic Veins in Noncardiac Diseases: What the Echocardiographer Should Know

In most instances, the flow profile in the hepatic veins (HVs) reflects the fluctuation of pressure within the right atrium. Thus, interrogation of blood flow in the HVs is highly useful for the evaluation of right heart hemodynamics and has become an integral part of any routine echocardiographic examination. However, flow in the HVs is also affected by the state of the liver parenchyma and by the fluctuation of pressure within the thoracic cavity. Therefore, liver and pulmonary pathologies influence the flow pattern in the HVs and may lead to its dissociation from right heart hemodynamics. Echocardiographers should familiarize themselves with the findings on HV Doppler in noncardiac diseases to avoid misinterpretation and incorrect diagnosis.

Pulsed-wave Doppler ultrasonographic evaluation of hepatic vein in dogs with tricuspid regurgitation

This study was performed to identify the relationships between hepatic vein (HV) measurements, including flow velocity and waveform, using pulsed-wave (PW) Doppler ultrasonography, and the severity of tricuspid regurgitation (TR) in dogs. The study included 22 dogs with TR and 7 healthy dogs. The TR group was subdivided into 3 groups according to TR jet profile obtained by echocardiography. The hepatic venous waveform was obtained and classified into 3 types. A variety of HV measurements, including the maximal velocities of the atrial systolic, systolic (S), end ventricular systolic, and diastolic (D) waves and the ratio of the S- and D- wave velocities (S/D ratio), were acquired. TR severity was significantly correlated with the S- (r = −0.380, p = 0.042) and D- (r = 0.468, p = 0.011) wave velocities and the S/D ratio (r = −0.747, p < 0.001). Receiver operating characteristic curve analysis revealed the highest sensitivity and specificity for the S/D ratio (89% and 75%, respectively) at a threshold of 0.97 with excellent accuracy (AUC = 0.911, p < 0.001). In conclusion, PW Doppler ultrasonography of the HV can be used to identify the presence of significant TR and to classify TR severity in dogs.

Standards of the Polish Ultrasound Society. Ultrasound examination of the portal system and hepatic vessels

Increased incidence of liver diseases, the development of liver surgery and other invasive methods for managing portal hypertension, plus an increasing number of liver transplant procedures pose more and more new challenges for ultrasonography. Ultrasonography, being an effective and clinically verified modality, has been used for several decades for diagnosing diseases of the liver, its vessels and portal hypertension. It is used for both initial and specialist diagnosis (performed in reference centers). The diagnostic value of ultrasonography largely depends on the knowledge of anatomy, physiology, pathophysiology and clinical aspects as well as on the mastering of the scanning technique. In the hands of an experienced physician, it is an accurate and highly effective diagnostic tool; it is of little use otherwise. The paper presents elements of anatomy, physiology and pathophysiology which make the portal system exceptional and the knowledge of which is crucial and indispensable for a correct examination and, above all, for the correct interpretation of results. The authors also present requirements regarding the equipment. Moreover, various technical aspects of the examination are presented and the normal morphological picture and hemodynamic parameters of healthy individuals are described. The authors discuss the most common clinical situations and rare cases during ultrasound examinations. The paper is based on the experience of the author who works in the largest center of liver diseases in Poland, and on the current literature.

Percutaneous Transhepatic Hepatic Vein Angioplasty in Budd-Chiari Syndrome After Transvenous Failure

PURPOSE

To evaluate the safety and efficacy of percutaneous transhepatic route creation for hepatic vein (HV) angioplasty in Budd-Chiari syndrome (BCS).

PATIENTS AND METHODS

Between April 2012 and August 2016, a total of 19 BCS patients underwent percutaneous transhepatic route creation for HV angioplasty after transvenous catheterization failure in this study. Color Doppler ultrasonography was required in all patients after admission and during follow-up. Data were retrospectively collected, and follow-up observations were performed.

RESULTS

Technical and clinical success was achieved in 18 patients. Except for 1 failure of route creation, 19 routes were successfully created in 18 patients, with a technology success rate of 95.0%. Twenty-two balloon angioplasties were performed in 18 patients, with a mean balloon diameter of 13.6 ± 0.5 mm. Blood pressure and length of occlusive HV decreased significantly, and blood flow velocity and diameter of HV increased significantly after procedure. Abdominal distension/pain and ascites decreased significantly after procedure. One procedure-related death occurred, who died of gastrointestinal bleeding 6 days later. Except for the failure case, the rest of 18 patients were successfully followed up. The remaining 18 patients survived during follow-up, with a 5-year survival rate of 94.9%. One patient had a restenosis of HV after 47 days, and had undergone successful dilation. The 5-year primary and second patency rates were 94.1% and 100%, respectively.

CONCLUSION

Percutaneous transhepatic route creation is safe and effective for HV angioplasty, and can be used to treat BCS patients after transvenous catheterization failure.

Deportalization, Venous Congestion, Venous Deprivation: Serial Measurements of Volumes and Functions on Morphofunctional 99mTc-Mebrofenin SPECT-CT

The objective was to assess the changes in regional volumes and functions under venous-impaired vascular conditions following liver preparation. Twelve patients underwent right portal vein embolization (PVE) (n = 5) or extended liver venous deprivation (eLVD, i.e., portal and right and middle hepatic veins embolization) (n = 7). Volume and function measurements of deportalized liver, venous-deprived liver and congestive liver were performed before and after PVE/eLVD at days 7, 14 and 21 using 99mTc-mebrofenin hepatobiliary scintigraphy with single-photon emission computed tomography and computed tomography (99mTc-mebrofenin SPECT-CT). Volume and function progressed independently in the deportalized liver (p = 0.47) with an early decrease in function (median −18.2% (IQR, −19.4–−14.5) at day 7) followed by a decrease in volume (−19.3% (−22.6–−14.4) at day 21). Volume and function progressed independently in the venous deprived liver (p = 0.80) with a marked and early decrease in function (−41.1% (−52.0–−12.9) at day 7) but minimal changes in volume (−4.7% (−10.4–+3.9) at day 21). Volume and function progressed independently in the congestive liver (p = 0.21) with a gradual increase in volume (+43.2% (+38.3–+51.2) at day 21) that preceded a late and moderate increase in function at day 21 (+34.8% (−8.3–+46.6)), concomitantly to the disappearance of hypoattenuated congestive areas in segment IV (S4) on CT, initially observed in 6/7 patients after eLVD and represented 35.3% (22.2–46.4) of whole S4 volume. Liver volume and function progress independently whatever the vascular condition. Hepatic congestion from outflow obstruction drives volume increase but results in early impaired function.

Hepatic vein tumor thrombosis in patients with hepatocellular carcinoma: Prevalence and clinical significance

BACKGROUND

There is strong evidence that portal vein tumor thrombosis (PVTT) is associated with poor survival in patients with hepatocellular carcinoma (HCC). However, data regarding the clinical significance of hepatic vein tumor thrombosis (HVTT) is rare, particularly in Western patients.

OBJECTIVE

To determine the HVTT prevalence in a Western patient population and its impact on survival.

METHODS

We included 1310 patients with HCC treated in our tertiary referral center between January 2005 and December 2016. HVTT and PVTT were diagnosed with contrast-enhanced cross-sectional imaging. Overall survival (OS) was calculated starting from the initial HCC diagnosis, and in a second step, starting from the first appearance of vascular invasion.

RESULTS

We observed macrovascular invasion (MVI) in 519 patients who suffered from either isolated HVTT (n = 40), isolated PVTT (n = 352), or both combined (HVTT + PVTT) (n = 127). Calculated from the initial HCC diagnosis, the median OS for patients with isolated HVTT was significantly shorter than that of patients without MVI (13.3 vs. 32.5 months, p < 0.001). Calculated from the first appearance of MVI, the median OS was similar among patients with isolated HVTT (6.5 months), isolated PVTT (5 months), and HVTT + PVTT (5 months). Multivariate analysis confirmed HVTT as an independent risk factor for poor survival.

CONCLUSIONS

HVTT may be more common than typically reported. In most patients, it was accompanied by PVTT. Isolated HVTT occurred less frequently and later than isolated PVTT; however, once developed, it had the same deleterious impact on survival. Therefore, patients with HVTT should be classified as advanced stage of HCC.

Hepatic venous Doppler assessment can anticipate simplified pulmonary embolism severity index and right ventricle dysfunction in patients with acute pulmonary embolism

PURPOSE

Acute pulmonary embolism (APE) is a life-threating cardiothoracic thromboembolic emergency in which right ventricle dysfunction (RVD) is a major concern. In the present study, we examined the hepatic veins (HVs) blood flow with pulsed-wave spectral Doppler ultrasonography to determine its relationship with the simplified pulmonary embolism severity index (sPESI) and the patient's RVD status.

METHODS

We divided the 243 patients who met the inclusion criteria into two groups based on both their sPESI scores and their RVD status. Transthoracic echocardiography was performed to evaluate the RVD and the HVs within 1 hour after patient admission. The liver was evaluated using subcostal and intercostal echocardiographic windows in grayscale B-mode, and HVs were assessed using color and spectral Doppler assessment though the same echocardiographic windows.

RESULT

A cut-off value of the systolic reverse flow velocity-time integral (SrVTI) = 2.2 cm carried a sensitivity and specificity of 84.29% and 74.89%, respectively, for the prediction of sPESI ≥ 1. A SrVTI cut-off value of 2.1 cm yielded a sensitivity and specificity of 83.03% and 73.91%, respectively, for the prediction of RVD.

CONCLUSION

HV Doppler assessment could be a useful method for anticipating the sPESI and the presence of RVD in patients with APE. In addition, it may provide information regarding the hemodynamic impact of APE.

Diagnostic Fleischner's sign in atrial septal defect

Fleischner sign is very rare in patients with ASD unless the defect remains undiagnosed till the elderly. For adulthood people with Fleischner sign, we should think about the possibility of congenital heart disease.