Surgical anatomy of retrohepatic inferior vena cava and hepatic veins: a quantitative assessment.

BACKGROUND: Accurate knowledge of the surgical anatomy of the retrohepatic inferior vena cava (IVC) and hepatic veins is necessary for hepatic surgery. METHODS: Lengths of different segments of retrohepatic IVC and their diameters, and prevalence of various types of ramification and lengths of different hepatic veins, were noted in 100 disease-free human livers during autopsy. RESULTS: The mean lengths of the IVC from entry into atrium to diaphragmatic hiatus, from the hiatus to the upper margin of right hepatic vein, between the upper margins of the right hepatic vein and the right suprarenal vein, from right suprarenal vein to the lowermost dorsal hepatic vein, and from the lower-most dorsal hepatic vein to the right renal vein were 29.1 mm, 8.6 mm, 40.6 mm, 28.6 mm and 33.7 mm, respectively. The mean diameter of IVC at the diaphragmatic level was 30.1 mm. The commonest ramification pattern of the hepatic veins was type I (82%) for the right hepatic vein, type II (63%) for the middle and left hepatic veins, and type II (55%) for the caudate veins. In 96% of cases the middle and left hepatic veins formed a common trunk. In a majority of cases, the diameters of the right and left hepatic veins were between 7 mm and 12 mm. No gender differences were found. CONCLUSION: This study provides an anatomical perspective for various hepatic surgical techniques.     

Surgical anatomy of the inferior vena cava ligament

BACKGROUND/AIMS: The inferior vena cava ligament is a fibrous membrane located around the inferior vena cava. Few reports exist on the ligament's location, attachment to the liver, or the inferior vena cava. METHODOLOGY: We obtained 16 specimens of human liver and inferior vena cava from cadavers. The inferior vena cava ligament was photographed and then dissected for histological examination. Relationships among the ligament, inferior vena cava, and liver were examined microscopically. The numbers and diameters of veins, arteries, and lymph vessels at least 1 mm in diameter were recorded. RESULTS: The cranial margin of the inferior vena cava ligament was ended in a blind loop. The cranial portion above the mid-portion of the Spiegel lobe was thicker than the caudal portion. The ligament was attached to the right and left hepatic veins. The mean length of the right side of the inferior vena cava ligament was 37.0 mm and the mean width 15.6 mm. The inferior vena cava ligament had a mean thickness of 0.8 mm (thin end) and 2.5 mm (thick end). Although the inferior vena cava ligament was usually tightly continuous with the liver capsule, microscopically the attachment between the ligament and the inferior vena cava was loose. The mean number and diameter of veins in the inferior vena cava ligament was 1.0 and 1.4 mm, respectively. The mean number and diameter of arteries was 0.2 and 2.4 mm, respectively. The mean number and diameter of lymphatic vessels was 2.8 and 1.7 mm, respectively. CONCLUSIONS: After dissection of the inferior vena cava ligament, major hepatic veins can be dissected extrahepatically. Because the ligament is wider caudally, the forceps should be inserted caudocranially during separation. Since both the number and diameters of lymphatic vessels in the ligament are large, the ligament should be ligated and cut.     

Asymptomatic membranous obstruction of the inferior vena cava forming intrahepatic collateral pathways

Intrahepatic and/or extrahepatic collateral pathways result from the membranous obstruction of the inferior vena cava. These collaterals are usually insufficient to prevent Budd-Chiari syndrome. We reprot an unusual case of asymptomatic membranous obstruction of the inferior vena cava in which marked intrahepatic collateral pathways were formed. Although the inferior vena cava terminated above the orifice of the right hepatic vein, the middle and left hepatic veins were patent above the membrane, without narrowing. Blood from the inferior vena cava drained into the right atrium via the intrahepatic collaterals between the right and middle hepatic veins without resistance.     

Liver hanging maneuver for right hemiliver in situ donation--anatomical considerations

Background. An anatomical study was carried out to evaluate the safety of the liver hanging maneuver for the right hemiliver in living donor and in situ splitting transplantation. During this procedure a 4–6 cm blind dissection is performed between the inferior vena cava and the liver. Short subhepatic veins entering the inferior vena cava from segments 1 and 9 could be torn with consequent hemorrhage. Materials and methods. One hundred corrosive casts of livers were evaluated to establish the position and diameter of short subhepatic veins and the inferior right hepatic vein. Results. The average distance from the right border of the inferior vena cava to the opening of segment 1 veins was 16.7±3.4 mm and to the entrance of segment 9 veins was 5.0±0.5 mm. The width of the narrowest point on the route of blind dissection was determined, with the average value being 8.7±2.3 mm (range 2–15 mm). Discussion. The results show that the liver hanging maneuver is a safe procedure. A proposed route of dissection minimizes the risk of disrupting short subhepatic veins (7%).     

Treatment of the Budd-Chiari syndrome with percutaneous transluminal angioplasty. Case report and review of the literature

A patient with the Budd-Chiari syndrome due to membranous obstruction of the right hepatic vein and long segmental obstruction of the inferior vena cava who was successfully treated with percutaneous transluminal angioplasty is described. Review of the literature revealed 14 prior cases of balloon dilatation of the hepatic venous system: 10 of the hepatic portion of the inferior vena cava, three of the right hepatic vein, and one of the left hepatic vein. Follow-up ranged from six months to 37 months. No serious complications were reported. All attempts at dilatation were successful, but reocclusion occurred in six patients, three of whom had occlusion of the hepatic vein. All but one patient with reocclusion, however, underwent repeated angioplasty, which was successful in all cases attempted. Two patients who had repeated angioplasty required no further therapy, but two patients required a total of three angioplasties and two patients required four angioplasties. Successful angioplasty was accompanied by resolution of clinical symptoms in all patients described. It is concluded that percutaneous transluminal angioplasty is a safe and effective mode of therapy in the management of the Budd-Chiari syndrome due to membranous obstruction of the hepatic portion of the inferior vena cava or the hepatic veins.     

The paracaval segments of the liver

Two segments constitute thedorsal sector: I to the left and in front of the inferior vena cava, and IX in front and to the right of the cava; they are united inferiorly by the caudate process. Segment I includes the caudate lobe, and segment IX is incorporated in the posterior surface of the right liver. Small dorsal pedicles, which are quite numerous, arise from the posterior margin of the main portal elements, and ascend upward. Segment I receives twigs from the left or right livers, many from the right lateral pedicle (67 biliary branches enter the right lateral duct, the unique duct in three cases). Segment IX consists of three subsegments. IXb lies under the interval between the middle and right superior hepatic veins, in 40% of the cases examined the veins come from the left portal vein or the bifurcation, in 6 cases the ducts enter the left hepatic duct, in 40 cases the branches extend higher than the plane of the main hepatic veins, in 18 cases reaching the upper surface of the liver. IXc is under the right hepatic vein, and IXd is to the right of a vertical plane passing by the right superior vein. Hepatic veins, enter the cava directly, sometimes the middle or the left hepatic veins.     

Methodology of renal vein renin study: comparison between simultaneous and sequential sampling (author's transl)

Purpose of this study has been to compare the results obtained using two different procedures in blood sampling from the renal veins for measuring renal venous renin. The first is the classical procedure which employs three catheters for simultaneous sampling from both renal veins and from the inferior vena cava, or from an artery. The other one is a simplified procedure which employs a single catheter that allows blood to be collected in the following rapid sequential manner: right renal vein, inferior vena cava, left renal vein, inferior vena cava. We have studied 13 patients (8 with essential hypertension, 5 with unilateral renal artery stenosis). Two catheters were introduced through a femoral vein and inserted into both renal veins; a third catheter was inserted into the femoral artery; then the blood sampling was performed strictly simultaneously. Soon after, the blood sampling was repeated according to the above mentioned sequential single catheter procedure. PRA was measured by Angiotensin I radioimmunoassay, then the Renal Vein Ratios (RVRR) were calculated. Even though as average of less than 20 seconds elapsed between the blood sampling in a renal vein and that in inferior vena cava, our results demonstrate that the release of renin can vary so quickly that erroneous informations may be obtained unless a strictly simultaneous sampling of blood is performed. In conclusion, our study demonstrates that the only reliable renal vein renin sampling procedure must employ the simultaneous renal venous and arterial (or inferior vena cava) blood collection.     

Anatomical basis of the liver hanging maneuver

BACKGROUND/AIMS: The anterior approach to right hepatectomy using the liver hanging maneuver without liver mobilization claims to be anatomically evaluated. During this procedure a 4 to 6-cm blind dissection between the inferior vena cava and the liver is performed. Short subhepatic veins, entering the inferior vena cava could be torn and a hemorrhage, difficult to control, could occur. METHODOLOGY: On 100 corrosive casts of livers the anterior surface of the inferior vena cava was studied to evaluate the position, diameter and draining area of short subhepatic veins and inferior right hepatic vein. The width of the narrowest point on the planned route of blind dissection was determined. RESULTS: The average value of the narrowest point on the planned route of blind dissection was 8.7+/-2.3mm (range 2-15mm). The ideal angle of dissection being 0 degrees was found in 93% of cases. In 7% we found the angle of 5 degrees toward the right border of inferior vena cava to be the better choice. CONCLUSIONS: Our results show that liver hanging maneuver is a safe procedure. With the dissection in the proposed route the risk of disrupting short subhepatic veins is low (7%).     

Leiomyosarcoma of the middle segment of the inferior vena cava: tactical problems raised by renal and caval revascularisation

INTRODUCTION: Leiomyosarcoma of the inferior vena cava is mesenchymal tumor accounting for 95% of primary tumors of the vena cava. Characteristic features include late invasion of adjacent structures and metastases, and delayed diagnosis. OBSERVATION: We report a case of inferior vena cava (IVC) leiomyosarcoma (LMS) found in a 53 year-old man who complained of abdominal pain. Morphologic exams found a very large polycyclic mass in the inferior vena cava involving the middle segment of the vena cava extending from the renal veins to the hepatic veins. An "en bloc" resection of the tumor was achieved. Caval outflow was restored using a ring-reinforced PTFE tube graft, the left renal vein was ligated and not re-implanted, the right renal vein was implanted in a lumbar sub-renal vein using a short prosthesis. Pathological examination documented a grade II leiomyosarcoma of the inferior vena cava and the patient was given adjuvant chemotherapy (anthracycline). One year later, there was no local or regional relapse. COMMENT: We emphasize the importance of restoring caval outflow which provides effective results when used with a ring-reinforced polytetrafluoroethylene (PTFE) prosthesis. Furthermore, the importance of restoring right renal outflow is highlighted because ligature of the renal vein can lead to renal ischemia and nephrectomy which should only be performed in specific cases. The tactical problems of renal and caval revascularisation, including the place of prosthetic replacement, are discussed.     

多排螺旋CT在检出右侧肾上腺静脉应用价值的初步探讨

目的:探讨多排螺旋CT(MDCT)对右侧肾上腺静脉检出率及右侧肾上腺静脉解剖结构显示情况。方法:402例行MDCT腹部三期增强扫描的患者,由两个不同的影像科医师观察其右侧肾上腺静脉轴位像和三维重建图像,进而评价右侧肾上腺静脉的情况。评价要点:可视化程度;右侧肾上腺静脉的直径与长度;与副肝静脉和其他静脉间的关系;右侧肾上腺静脉的位置及与周围结构间的关系,与下腔静脉的方向关系。结果:402例患者检出右侧肾上腺静脉338例(84.1%),其中,有31例(9.2%)右侧肾上腺静脉与副肝静脉共干,右侧肾上腺静脉开口位于胸11~腰1之间。另307例患者中,在横断面上右侧肾上腺与下腔静脉横方向关系为向后和向右的占282例(91.9%),向后和向左的占25例(8.1%);在垂直面上右侧肾上腺朝向下腔静脉尾侧有292例(95.1%),头侧为15例(4.9%)。在这338例患者中,右侧肾上腺静脉的长度和直径分别为平均(3.8±1.7)mm和(1.7±0.6)mm。结论:MDCT有较高检出右侧肾上腺静脉的能力,并能大致显示其解剖特征,包括它的位置和与周围结构的关系。     

Analysis of Hepatic Vein Waveform by Doppler Ultrasonography in 100 Patients with Portal Hypertension

Objectives : We classified the Doppler waveform seen in patients with portal hypertension and examined the associations of the waveform type with the diagnosis of Budd-Chiari syndrome and severity of the liver cirrho-sis. Methods : The Doppler pattern of right and left hepatic veins in 100 consecutive Japanese patients with portal hypertension and esophagogastric varices was classified into six types: 1, triphasic waveform; IF, bi-phasic waveform without reversed flow; III, decreased amplitude of phasic oscillations; IV, flat waveform with fluttering; V, completely flat waveform with fluttering; VI, no waveform. All patients underwent computed tomography and magnetic resonance imaging. Patients in whom hepatic vein waveform showed type IV, type V, or type VI, positively underwent hepatic venography and inferior vena cavography. Resuits: Type I was seen in 31 of 100 patients, type II in 35, type III in 17, type IV in eight, type V in four, and type VI in five. Types I-IV waveform indicated no lesion in hepatic veins and inferior vena cava, type V indicated stenosis of hepatic veins or occlusion of inferior vena cava, and type VI, occlusion of hepatic veins. For one patient with type V hepatic veins, halloon angioplasty was done, and the waveform changed from type V to type II. Examining the relationship between hepatic vein waveform and the Child-Pugh score, liver function of type IV cases was worse than tbat of type I cases in 66 cirrhotie patients witbout bepatocellular carcinoma(p < 0.05). Tbere was no clear relutionship between bepatic vein waveform and portal venous perfusion, as based on Nordlinger's grade. Conclusions: Our classiflcation of hepatic vein waveform in Doppler ultrasonography is useful in di-agnosing Budd-Cbiari syndrome, in judging the effi-ciency of treatment for bepatic vein lesions, and in assessing severe liver function in cirrbotic patients.     

Middle hepatic vein reconstruction of graft for a patient with intrahepatic portosystemic shunt

Middle hepatic vein reconstructions for modified right liver grafts in living donor liver transplantation provide satisfactory results. We report a patient who had undergone transjugular intrahepatic portosystemic shunt before living donor liver transplantation, in which the middle hepatic vein was reconstructed using a preserved great saphenous vein. A 41-year-old Japanese man with a 5-year history of alcoholic liver cirrhosis and esophageal varices was admitted to our hospital for living donor liver transplantation. He had undergone endoscopic variceal ligations and transjugular intrahepatic portosystemic shunt for esophageal variceal bleeding, and ascites. He had living donor liver transplantation, which was performed using his sister's right lobe without the middle hepatic vein. The recipient's estimated standard liver volume calculated by abdominal computer-assisted tomography was 1166 mL. The exact weight of the donor's right lobe was 507 g, which was equivalent to 44% of the recipient's standard liver volume. At bench surgery, the middle hepatic vein was reconstructed using a preserved great saphenous vein, which was cut in 2 strips to make a thicker tube graft by suturing, and subsequently, the newly made tube graft end was anastomosed to V5 and V8 branches of the graft. The metallic stent for transjugular intrahepatic portosystemic shunt buried in the recipient's right hepatic vein was removed with the right hepatic vein. The other end of the saphenous tube graft was anastomosed to the right anterior aspect of the vena cava. Stumps of the middle and left hepatic veins were oversewn. Postoperative blood flow in the graft and the reconstructed hepatic veins has been satisfactory with normal liver functions.     

Modified techniques for adult-to-adult living donor liver transplantation

BACKGROUND: Because of critical organ shortage, transplant professionals have utilized living donor liver transplantation (LDLT) in recent years. We summarized our experience in adult-to-adult LDLT with grafts of right liver lobe by a modified technique. METHODS: From January 2002 to August 2005, 24 adult patients underwent living donor liver transplantation with grafts of the right liver lobe at West China Hospital, Sichuan University, China. Twenty-two patients underwent modi-Bed procedures designed to improve the reconstruction of the right hepatic vein and the tributaries of the middle hepatic vein by interposing a great saphenous vein ( GSV) graft and the anastomosis of the hepatic arteries and bile ducts. RESULTS: No severe complications and death occurred in all donors. In the first 2 patients, (patients 1 and 2), operative procedure was not modified. One patient suffered from "small-for-size syndrome" and the other died of sepsis with progressive deterioration of graft function. In the rest 22 patients (patients 3 to 24), however, the procedure of venous reconstruction was modified, and better results were obtained. Complications occurred in 7 recipients including acute rejection (2 patients), hepatic artery thrombosis (1), bile leakage (1), intestinal bleeding (1), left sub-phrenic abscess (1), and pulmonary infection (1). One patient with pulmonary infection died of multiple organ failure (MOF). The 22 patients underwent direct anastomosis of the right hepatic vein to the inferior vena cava (IVC), 9 direct anastomosis plus the reconstruction of the right inferior hepatic vein, and 10 direct anastomosis plus the reconstruction of the tributaries of the middle hepatic vein by in-terpos-ing a GSV graft to provide sufficient venous outflow. Trifurcation of the portal vein was met in 3 patients. Venoplasty or separate anastomosis was performed. The ratio of graft to recipient body weight ranged from 0.72% to 1.17%. Among these patients, 19 had the ratio <1.0% and 4 <0.8%, and the ratio of graft weight to recipient standard liver volume was between 31.86% and 62.48%. Among these patients, 10 had the ratio <50% and 2 <40%. No "small-for-size syndrome" occurred in the 22 recipients who were subjected to modified procedures. CONCLUSIONS: With the modified surgical techniques for the reconstruction of the hepatic vein to obtain an adequate outflow and provide a sufficient functioning liver mass, living donor liver graft in adults using the right lobe can be safe to prevent the "small-for-size syndrome".     

How to explant a diseased liver for living donor liver transplantation after previous gastrectomy with severe adhesion (with video)

We performed living donor liver transplantation (LDLT) in a patient who had undergone distal gastrectomy for gastric ulcer disease with Billroth I reconstruction 30 years before the LDLT. The adhesion was very severe between remnant stomach and hepatic hilum as well as left liver lobe with shortening of hepatoduodenal structures. After dissection of the infrahepatic inferior vena cava, the Spiegel lobe was identified from the dorsal side. The Spiegel lobe was then penetrated with a right angle dissector so that a plastic tape could be placed around the whole adhesion, including important structures in the hepatoduodenal ligament. Next, the right hepatic vein was transected with a vascular stapler using Pringle's maneuver using the plastic tape to fasten the entire adhesional structure. Subsequently, the trunk of the middle and left hepatic vein was transected after clamping. The remaining short hepatic veins in the left side were divided completely from the cranial to the caudal direction to dissect Spiegel's lobe. Finally, the hepatoduodenal ligament was identified from the attached remnant stomach and the duodenum and a vascular clamp was placed on the entire hepatoduaodenal ligament. Finally, the diseased liver was explanted for graft implantation. Thus, retrograde explantation of the liver was effective in decreasing the risk of damaging vital elements in the hepatoduodenal ligament, the remnant stomach, and the duodenum.     

Complex hepatic outflow reconstruction in domino liver transplantation

Domino liver transplantation has been accepted as a safe procedure to further expand the organ donor pool. The most important technical challenge of the procedure resides in restoring a proper hepatic venous allograft outflow in the familial amyloidotic polyneuropathy-liver recipient. To overcome this issue, combined techniques were used to perform an innovative outflow reconstruction. A domino liver transplantation was successfully performed with reconstruction of complex venous outflow. The inferior vena cava sparing hepatectomy technique in the familial amyloidotic polyneuropathy-donor was used to cut the hepatic vein to the liver parenchyma. To overcome this issue the venous outflow tract was reconstructed using a longitudinally opened iliac vein graft from a post-mortem donor to create a new outflow tract using a diamond patch between the right and middle/left hepatic veins.     

Two dimensional echocardiographic diagnosis of situs.

At present there is no reliable method of recognising atrial isomerism by two dimensional echocardiography. We therefore used two dimensional echocardiography to examine 158 patients including 25 with atrial isomerism and four with situs inversus. Particular attention was paid to the short and long axis subcostal scans of the abdomen. Using the position of the inferior vena cava and the aorta with respect to the spine it was possible to separate those with situs solitus from the others. Two false positives for abnormal situs had exomphalos. In situs solitus the aorta lay to the left of the spine and the inferior vena cava lay to the right. One patient with situs solitus and azygos continuation of the inferior vena cava also had inferior vena cava to right atrial connection. In the four patients with situs inversus the mirror image of the normal pattern was present. In nine patients with right isomerism the inferior vena cava and aorta ran together on one or other side of the spine. The inferior vena cava, anterior to the aorta at the level of the diaphragm, received at least the right hepatic veins (normal or partial anomalous hepatic venous connection). Of the 16 patients with left isomerism, 14 had azygos continuation of the inferior vena cava which was visualised posterior to the aorta in all but two. All patients with left isomerism had total anomalous hepatic venous connection to one or both atria via one or two separate veins. Two dimensional echocardiography therefore provides the means of detecting abnormal atrial situs and of diagnosing right or left isomerism in the great majority of patients, if not all.     

Hepatic resection through an anterior approach employing a modified liver hanging maneuver in patients with a massive liver tumor severely oppressing the inferior vena cava

For a large hepatic neoplasm existing in the right hepatic lobe, hepatic resection using an anterior approach is required. We have reported an operative procedure for hepatic transection using absorbable polyglycolic acid tape. In patients with suspected tumor invasion of the inferior vena cava, on the other hand, considering the range of the residual tumor while sparing the inferior vena cava as much as possible, combined resection and reconstruction of the inferior vena cava is conducted only if operative curativity is expected. We conducted hepatic transection while maintaining the blood flow of the residual liver by applying the liver hanging maneuver method of Belghiti et al. and polyglycolic acid tape in patients with giant liver tumors of the right hepatic lobe compressing the hepatic inferior vena cava. Strong angled dissecting forceps were inserted into the ventral side of the inferior vena cava from the caudal side, and the tip was induced between hepatic veins. Two strips of polyglycolic acid tape were pinched with forceps and strongly ligated on the right and left sides of the cutoff line. Subsequently, hepatic transection was conducted using electrocautery spray coagulation and CUSA without blocking the inflow blood of the residual liver, and the right hepatic lobe was extirpated. This procedure has already been performed in 5 patients suspected of inferior vena cava invasion, and the inferior vena cava was able to be preserved in all the patients.     

How Close Are the Phrenic Nerves to Cardiac Structures? Implications for Cardiac Interventionalists

BACKGROUND: Phrenic nerve injury is a recognized complication following cardiac intervention or surgery. With increasing use of transcatheter procedures to treat drug-refractory arrhythmias, clarification of the spatial relationships between the phrenic nerves and important cardiac structures is essential to reduce risks. METHODS AND RESULTS: We examined by gross dissection the courses of the right and left phrenic nerves in 19 cadavers. Measurements were made of the minimal and maximal distances of the nerves to the superior caval vein, superior cavoatrial junction, right pulmonary veins, and coronary veins. Histologic studies were carried out on tissues from six cavaders. Tracing the course of the right phrenic nerve revealed its close proximity to the superior caval vein (minimum 0.3 +/- 0.5 mm) and the right superior pulmonary vein (minimum 2.1 +/- 0.4 mm). The anterior wall of the right superior pulmonary vein was <2 mm from the right phrenic nerve in 32% of specimens. The left phrenic nerve passed over the obtuse cardiac margin and the left obtuse marginal vein and artery in 79% of specimens. In the remaining specimens, its course was anterosuperior, passing over the main stem of the left coronary artery or the anterior descending artery and great cardiac vein. CONCLUSIONS: The right phrenic nerve is at risk when ablations are carried out in the superior caval vein and the right superior pulmonary vein. The left phrenic nerve is vulnerable during lead implantation into the great cardiac and left obtuse marginal veins.     

Relationship between mean right atrial pressure and Doppler parameters in patients with right ventricular infarction

BACKGROUND: The incidence of an inferior left ventricular infarction involving the right ventricle is very high, ranging from 14 to 84%. Isolated right ventricular infarction accounts for < 3% of all cases of infarction. HYPOTHESIS: The aim of the present study was to assess the relationship between Doppler parameters of hepatic vein and tricuspid inflow, as well as mean right atrial (RA) pressure in patients with right ventricular infarction. METHODS: In all, 59 consecutive patients with inferior left ventricular infarction involving the right ventricle were selected for the study. All patients underwent Doppler echocardiographic evaluation of tricuspid and hepatic vein parameters and catheterization of the right side of the heart. Patients were divided into two groups according to the presence or absence of severe tricuspid regurgitation. RESULTS: In patients with severe tricuspid regurgitation, a significant correlation (r = 0.64; p < 0.001) between RA maximal volume and mean right atrial pressure (RAP) was found, and the sensitivity of RA maximal volume in identifying mean RAP > 7 mmHg was 64% with a specificity of 78%. In patients without severe tricuspid regurgitation, the most significant relationship was observed between mean RAP and inferior vena cava collapse index. Significant correlations between maximal and minimal diameters of the inferior vena cava were also observed. CONCLUSIONS: Echocardiographic and Doppler parameters may be useful for evaluating mean RAP in patients with right ventricular infarction. In patients with severe tricuspid regurgitation, the more important parameters are maximal and minimal RA volumes. In patients without severe tricuspid regurgitation together with right atrial volume, the important parameters are acceleration and deceleration time of the tricuspid inflow peak E velocity and hepatic systolic and diastolic venous flow.     

Measurements of central blood vessels in infants and children: normal values.

In order to provide physicians interpreting vascular radiographic studies with normal data regarding central blood vessel size in children and to facilitate the design and adaptation of intravascular devices for pediatric use, we measured lengths and diameters of central blood vessels in 141 radiographic studies in 136 children. The diameters of the following vessels were determined: right and left internal jugular veins and common carotid arteries; the inferior vena cava and the descending thoracic aorta; right and left iliac veins; and right and left femoral veins and arteries. In addition, the lengths of the inferior vena cava and the descending aorta were also determined. Blood vessel dimensions were highly correlated with age, height, weight, and body surface area. The linear regression equations for each measured dimension against age, weight, height, and surface area are provided, along with a table of predicted vessel size as a function of age.