A review of the anatomy and clinical significance of adrenal veins

The adrenal veins may present with a multitude of anatomical variants, which surgeons must be aware of when performing adrenalectomies. The adrenal veins originate during the formation of the prerenal inferior vena cava (IVC) and are remnants of the caudal portion of the subcardinal veins, cranial to the subcardinal sinus in the embryo. The many communications between the posterior cardinal, supracardinal, and subcardinal veins of the primordial venous system provide an explanation for the variable anatomy. Most commonly, one central vein drains each adrenal gland. The long left adrenal vein joins the inferior phrenic vein and drains into the left renal vein, while the short right adrenal vein drains immediately into the IVC. Multiple variations exist bilaterally and may pose the risk of surgical complications. Due to the potential for collaterals and accessory adrenal vessels, great caution must be taken during an adrenalectomy. Adrenal venous sampling, the gold standard in diagnosing primary hyperaldosteronism, also requires the clinician to have a thorough knowledge of the adrenal vein anatomy to avoid iatrogenic injury. The adrenal vein acts as an important conduit in portosystemic shunts, thus the nature of the anatomy and hypercoagulable states pose the risk of thrombosis. Clin. Anat. 27:1253–1263, 2014. © 2014 Wiley Periodicals, Inc.     

An anatomical classification of the variations of the inferior phrenic vein

The majority of anatomical textbooks of gross anatomy offer very little information concerning the anatomy and distribution of the inferior phrenic vein (IPV). However, in the last decade, an increasing number of reports have arisen, with reference to the endoscopic embolization of esophageal and paraesophageal varices, as well as venous drainage of hepatocellular carcinomas (HCC). The IPV is one of the major sources of collateral venous drainage in portal hypertension and HCC. The aim of this study was to identify the origin and distribution of the IPVs (right and left), both in normal and (selective) pathological cases. We have examined 300 formalin-fixed adult cadavers, without any visible gastrointestinal disease, and 30 cadavers derived from patients with HCC. The right IPV drained into the following: the inferior vena cava (IVC) inferior to the diaphragm in 90%, the right hepatic vein in 8%, and the IVC superior to the diaphragm in 2%. The left IPV drained into the following: the IVC inferior to the diaphragm in 37%, the left suprarenal vein in 25%, the left renal vein in 15%, the left hepatic vein in 14%, and both the IVC and the left adrenal vein in 1% of the specimens. The IPVs possessed four notable tributaries: anterior, esophageal, lateral and medial. The right IPV served as one of the major extrahepatic draining veins for all 30 cases of HCC. These findings could have potential clinical implications in the transcatheter embolization of esophageal and paraesophageal varices, as well as in mobilizing the supradiaphragmatic segment of IVC.     

Clinical implications of concomitant variations of the testicular, suprarenal and renal veins: A case report

Multiple venous anomalies have been observed during dissection of the posterior abdominal wall in a 65-year-old, white male cadaver. The left testicular and suprarenal veins united inferior to the superior mesenteric artery, coursed anterior to the abdominal aorta and drained into the inferior vena cava (IVC). Further the left renal vein coursed retroaortically and divided into three branches. The superior branch coursed on the vertebral column and drained into the azygos vein while middle and inferior branches drained into the IVC. The right renal vein was double and both drained into the IVC separately. Due to implications for numerous therapeutical and diagnostic procedures in the retroperitoneal region knowledge of these variations could be useful for clinicians in its recognition and protection.     

Three patterns of extra-testicular venous drainage in the rabbit. Divergence from a traditional concept

Summary Seventy-eight male New Zealand white rabbits were autopsied and found to have variable left extra-testicular venous anatomy. Our observations reveal that in the rabbit the left testis is drained in one of three ways, identified as either A (18%), B (30%) or C (52%) —type drainage. The right testicular vein in all cases drained directly into the inferior vena cava immediately superior to the right iliolumbar vein.In type A drainage, the left testicular vein drained directly into the inferior vena cava at the level of the left iliolumbar vein. In type B drainage, the left testicular vein emptied into the left iliolumbar vein, which in turn drained into the inferior vena cava. In type C drainage both the left testicular and iliolumbar veins anastomosed to form a lumbotesticular trunk which emptied directly into the left renal vein.These three patterns of left venous vascular anatomy in the rabbit can be explained on the basis of their embryologic development. Our observations suggest that it is the caudal segment of the left pelvic subcardinal vein and its anastomosis with the caudal cardinal complex which persist as the left testicular vein and that the more cranial segment of this vein, heretofore presumed to remain patent, atrophies to the level of the developing left renal vein.     

肾上腺静脉MSCT影像解剖研究

目的　利用MSCT准确显示肾上腺静脉正常解剖结构及变异,为临床提供影像解剖数据。 方法　回顾分析上腹部CTA患者108例。薄层MIP/MPR评估测量肾上腺静脉管径、长度及走行路径。 结果　①右侧：显示率64.81%（70/108）,变异5.71%(4/70);汇入下腔静脉7点至8点间占优势42.42%;其管径Rr (2.19±0.56) mm,腺外段长度RD1 (5.02±1.82) mm,汇入下腔静脉距右肾静脉汇入距离RD2 (40.69±12.96) mm,汇入口开口向下角度RA (60.25±17.85)°。②左侧：显示率97.22%（105/108）;变异14.29%（15/105）;肾上腺静脉管径Lr (2.39±0.56) mm,腺外段长度LD1 (7.28±4.01) mm,膈-肾上腺静脉干管径LR (3.65±0.93) mm,膈-肾上腺静脉的共干段长度LD2 (14.07±6.77) mm,膈-肾上腺静脉汇入左肾静脉点至下腔静脉左侧缘距离LD3 (32.89±4.85) mm,膈-肾上腺静脉汇入左肾静脉开口向内的角度LA1 (118.06±18.49)°,肾上腺静脉与膈静脉共干段开口向下的角度LA2 (156.15±13.81)°。 结论　MSCT可显示大部分右侧肾上腺静脉及绝大部分左侧肾上腺静脉正常走行及变异,测量相关影像解剖数据,为AVS等手术方案提供影像数据。     

Multiple variations of the renal and testicular vessels: possible embryological basis and clinical importance

During routine dissection of the abdominal cavity of a 55-year-old African male cadaver, multiple anomalies including renal and testicular vessels were encountered. The right kidney was supplied by three right hilar renal arteries arising from the abdominal aorta at different vertebral levels whereas only one left renal artery supplied the left kidney. On the right three renal veins drained the kidney into the inferior vena cava. In contrast, the left kidney was drained by a single renal vein which received a large primary posterior tributary. The primary posterior tributary had three tributaries from the posterior lumbar region. The right testis had two sources of arterial supply; one from the subcostal artery and another from the abdominal aorta. The left testis was supplied normally by a single testicular artery. The right testis was drained by four testicular veins as follows: one drained into the subcostal vein, the other two drained separately for a longer course and joined shortly before draining into the right main renal vein, the fourth one drained into the anterior aspect of the inferior vena cava at the level of the second lumbar vertebra. On the left, the testicle was drained by two testicular veins which travelled separately from the deep inguinal ring and joined shortly before they drain into the left renal vein. This variation may represent an immature form of complicated development of kidneys and testes. Additionally, emphasis must be put on preoperative vascular examination to avoid surgical complications from variant vessels in this region.     

正常引流肺静脉解剖变异的多层螺旋CT血管成像研究

目的 探讨正常引流肺静脉的解剖变异率及其变异形式。方法 回顾性分析2013年5月—2014年7月中山大学附属孙逸仙纪念医院220例两侧肺静脉均引流至左心房患者的胸部64层螺旋CT血管成像(MSCTA)资料,对肺静脉进行多平面重建(MPR)、最大强度投影(MIP)及VR重建,观察段以上肺静脉引流区域,以及双侧肺静脉与左心房连接模式。两侧肺静脉分别以上、下肺静脉独立开口于左房,右中叶肺静脉回流至上肺静脉者为正常肺静脉引流模式;一侧单支或多于两支肺静脉引流、跨叶引流者为肺静脉解剖变异。结果 220例正常引流肺静脉中,左右肺静脉总变异发生率22.7%(50/220)。右肺静脉解剖变异38例(17.3%,38/220),共见8种变异模式,分别为:(1)上、下叶肺静脉分别汇入左心房,中叶静脉汇入下叶肺静脉 4例(1.8%,4/220);(2)上、下叶肺静脉分别汇入左心房,上叶后段汇入下叶肺静脉2例(0.9%,2/220);(3)上、中、下叶静脉分别汇入左心房16例(7.3%,16/220);(4)上叶后段、尖前段、下叶肺静脉分别汇入左心房,中叶静脉汇入尖前段肺静脉4例(1.8%,4/220);(5)上叶、下叶背段、下叶基底段肺静脉分别汇入左心房,中叶静脉汇入上叶肺静脉2例(0.9%,2/220);(6)上叶、 中叶内段、中叶外段、下叶肺分别静脉汇入左心房6例(2.7%,6/220);(7)上叶后段、上叶尖前段、中叶、下叶肺静脉分别汇入左心房2例(0.9%,2/220);(8)上叶、中叶、下叶背段、下叶基底段肺静脉分别汇入左心房2例(0.9%,2/220)。左肺静脉变异12例(5.5%,12/220),共见2种变异模式,即上、下叶肺静脉组成共干汇入左心房8例(3.6%,8/220),上叶、舌叶、下叶肺静脉分别汇入左心房4例(1.8%,4/220)。220例患者中,左右肺静脉解剖变异率的差异有统计学意义(χ²＝13.533, P<0.01)。结论 MSCTA上正常引流肺静脉解剖变异常见,右肺静脉解剖变异发生率显著高于左肺静脉,且变异模式多样。     

双下腔静脉的MSCT表现及临床意义

目的　探讨双下腔静脉（inferior vena cava,IVC）的多层螺旋CT（multi-slice spiral CT,MSCT）表现及临床意义。 方法　收集经腹部MSCT多期增强扫描发现的18例双IVC患者,采用MPR、MIP和VR等血管成像技术显示IVC解剖,回顾性分析患者临床及影像学资料,结合文献讨论双IVC影像学特征、胚胎学机制及临床意义。 结果　18例双IVC的MSCT表现为3种类型。Ⅰ型83.33%（15例）表现为左侧IVC上行至左肾静脉汇入,再以左肾静脉正常方式经主动脉前方右行,汇入正常的右侧IVC。Ⅱ型11.11%（2例）表现为右侧IVC上行达腰2椎体平面,经腹主动脉后方左行汇入左侧IVC,后者再上行延续为半奇静脉,然后经奇静脉和上腔静脉汇入右心房;右肾静脉主要汇入右侧肾上段IVC,但存在侧支与右侧肾下段IVC相连。Ⅲ型5.56%（1例）表现为右侧IVC全程行径正常,左侧IVC垂直上行接收左肾静脉汇入后,于主动脉后方向右上走行与奇静脉连接。 结论　双IVC有多种复杂的变异类型,对于腹膜后手术及下半身静脉血栓治疗具有重要的临床意义。     

A case of double inferior vena cava with renal,ovarian and iliac vein variation

We encountered a rare case of an anatomic variant of inferior vena cava (IVC) duplication with renal, ovarian and iliac vein variation in an 81-year-old Japanese female cadaver during a student dissection course of anatomy at Aichi Gakuin University School of Dentistry. The two IVCs ran upwards bilaterally to the abdominal aorta. The left IVC joined with the left renal vein (RV) to form a common trunk that crossed anterior to the aorta and ended at the right IVC. We detected a vein [interiliac vein (IiV)] connecting the two IVCs at the level of the aortic bifurcation. The IiV was formed by the union of two tributaries from the left IVC and a tributary from the left internal iliac vein (IIV) and ran obliquely upwards from left to right. Two right ovarian veins, arising separately from the ipsilateral pampiniform plexus, ran vertically in parallel to each other, and each one independently terminated at the right IVC and the right RV. Two right IIVs, connecting each other with small branches, ascended and separately joined the right external iliac vein. The right and left IIVs were connected to each other. These variations cause abnormal drainage, which could lead to clinical symptoms associated with the dysfunction of the vascular and urogenital systems. Here we describe the detailed anatomical features of the area and discuss the related anatomical and developmental aspects.     

Simultaneous aberrant left and right gastric veins draining directly into the liver.

Aberrant gastric veins draining directly into the liver are rare variations of the portal vein system. We report on an autopsy in which both right and left gastric veins drained directly into the liver without joining the portal vein. Although the left gastric artery adopted a standard disposition, the left gastric vein was indeed found to ascend from the lesser curvature through the upper part of the lesser omentum. After receiving branches from the gastroesophageal junction, it directly entered the left part of the porta hepatis. The right gastric vein ascended from the lesser gastric curvature along and in front of the right aspect of the common bile duct without ending in the portal vein. It crossed in front of the common hepatic duct and directly entered the porta hepatis. Careful dissection within the liver parenchyma showed that both gastric veins ended in the intra-hepatic part of the left branch of the portal vein. Although aberrant gastric veins are known variations of the portal vein system, the conjunction of both right and left gastric vein has never been reported. It highlights the possibility that the venous drainage of the gastric lesser curvature may be totally independent of the main portal vein.     

Variations of the iliac and pelvic venous systems with special attention to the drainage patterns of the ascending lumbar and iliolumbar veins

The anatomy of the inferior vena cava (IVC) and common, external and internal iliac veins (CIV, EIV, IIV respectively) was examined in 59 embalmed adult human cadavers of Caucasian origin. In the present study, we focus our attention on the drainage patterns of the ascending lumbar and iliolumbar veins (ALV, ILV) when there are variations in the major pelvic veins by highlighting and describing the variations themselves. The above patterns, when no variations exist, have already been reported. Among the 59 cadavers, nine (9/59, 15.3%) presented anomalies of the major pelvic veins, as follows: anomalous drainage of both EIV and IIV in 8.5% of the specimens (5/59, Type I); variations of the IVC in 3.4% (2/59, Type II); duplication of the IIV (1/59=1.7%, Type III); anastomotic branch between the right IIV and the left CIV (1/59=1.7%, Type IV). ALV drained either into the CIV (8/18 sides, 44.4%) or in EIV (5/18 sides, 27.8%), while absence of ILV was the most frequent pattern (8/18 sides, 44.4%). A common trunk, joining the two veins, was observed in 5/18 sides (27.8%). Those drainage patterns were in accordance with the ones discovered in our previous study. In Type I the two veins always drained into the EIV. Knowledge of the surgical anatomy of all studied veins may prevent injury to these veins during operations in the retroperitoneal space and pelvis or malposition of venous catheters placed from the groin.     

Duplication of the inferior vena cava associated with other variations

Multiple vascular variations, including duplication of the inferior vena cava, double renal arteries and anomalies of the testicular blood vessels, were observed during dissection of the retroperitoneal region of a cadaver of an 87-year-old Japanese man. The right inferior vena cava arose from the union of right common iliac veins and a thinner interiliac vein. This interiliac vein ascended obliquely from right to left and joined the left common iliac veins to form the left inferior vena cava. The right and left inferior venae cavae were of approximately equal width. The right testicular vein consisted of medial and lateral venous trunks. The two venous trunks coalesced to form a single vein, which drained into the confluence of the right inferior vena cava and right renal vein. The left testicular vein was composed of the medial and lateral testicular veins, which drained into the left renal vein. Double renal arteries were seen bilaterally, which originated from the lateral aspects of the abdominal aorta. The right testicular artery arose from the right inferior renal artery and accompanied the lateral trunk of the right testicular vein running downwards. The left testicular artery arose from the ipsilateral inferior renal artery and ran downwards accompanied by the left lateral testicular vein. In addition, the bilateral kidneys showed multicystic changes.     

Duplicate testicular veins accompanied by anomalies of the testicular arteries.

Duplicate testicular veins associated with other anomalies of the testicular arteries were observed during dissection of the posterior abdominal wall in a 90-year-old Japanese male cadaver. The right testicular vein was composed of the medial and lateral testicular veins. The medial testicular vein drained into the inferior vena cava, whereas the lateral testicular vein drained into the confluence of the inferior vena cava and right renal vein. Several anastomosing branches were seen between the medial and lateral testicular veins. The left testicular vein was formed after the medial and lateral venous trunks joined and drained into the ipsilateral renal vein. The right testicular artery originated from the anterior surface of the abdominal aorta at the level of the left renal artery, passed posterior to the inferior vena cava, and accompanied the right lateral testicular vein running downwards. The left testicular artery arose from the abdominal aorta at a level of 5 cm below the origin of the right testicular artery, and then ran downwards accompanied by the medial trunk of the left testicular vein.     

Infra-renal angles, entry into inferior vena cava and vertebral levels of renal veins.

Current norms for renal vasculature hold true in only half the population. Standard textbooks perpetuate old misconceptions regarding renal venous anatomy. This study is aimed to determine left and right infra-renal angles (L-IRA, R-IRA); entry level of renal veins into the inferior vena cava (IVC), and height of IVC under renal vein influence; and their vertebral level. One hundred morphologically normal en-bloc renal specimens randomly selected from post-mortem examinations were dissected and resin casted. IRA were also measured from venograms of 32 adult and 11 foetal cadavers, as were vertebral entry levels. IRA measurements (degrees) were as follows: left, 55 degrees +/- 16 degrees (20 degrees -102 degrees ); right, 60 degrees +/- 17 degrees (10 degrees -93 degrees ). Left vein entered IVC higher than right 54%, lower 36%, and opposite each other 10%. Vertical distance between lower borders of veins was 1.0 +/- 0.9 cm. Vertical distance of IVC under renal vein influence was 2.3 +/- 1.0 cm. Vertebral level of veins in adults lies between TI2-L2. In foetuses, IRA was as follows: left, 65 degrees +/- 12 degrees (45 degrees -90 degrees ); right, 58 degrees +/- 7 degrees (40 degrees -70 degrees ); vertebral level between T12 and L3. Similar IRA values from literature noted on right, 51 degrees (26 degrees -100 degrees ); differences on left, 77 degrees (43 degrees -94 degrees ), clearly differing from Williams et al. (Gray's Anatomy, 37(th) ed, 1989) statement that renal veins "open into the inferior vena cava almost at right angles." Large variations of IRA are not surprising since kidneys are considered normally "floating viscera," varying position with posture and respiratory movement as well as in live vs. cadaveric subjects. The entry level into the IVC also differs from Williams et al. This study uniquely quantitated actual height difference between lower borders of left and right veins. The data presented appears to be the first documentation of vertebral level of entry of renal veins into IVC in foetuses. These findings are clinically important for the angiographer, catheter design, and planning porto-renal shunt procedures.     

Breathing Life into the Cadaver: Introducing Air Dissection As a New Teaching and Dissecting Method for the Venous System

Air insufflation has been used for various surgical procedures such as during laparoscopy. We hypothesized that the use of pressurized air might enable cadaveric dissection to differentiate smaller veins better than traditional dissection techniques. In three fresh‐frozen cadavers, the inferior vena cava (IVC) and right or left femoral veins were exposed just distal to the inguinal ligament and a needle placed into one of them. Pressurized air was then placed into the cannulated femoral vein using an air compressor. In all specimens, the IVC and most of its tributaries, both left and right sides, were clearly insufflated. When the IVC was traced superiorly by resecting the diaphragm through the caval foramen, the right atrium and ventricle were also found to be dilated. Additionally, venous variants that would have not been obvious without dilatation of the IVC were identified. Air dissection of the venous system in fresh‐frozen cadavers aids in anatomical dissection. Such a model might also serve as a surgical training model and teaching tool as it better mimics life‐like anatomy and physiology. We term this technique “cadaveric air dissection.” Clin. Anat. 32:566–572, 2019. © 2019 Wiley Periodicals, Inc.     

Variations of the bilateral testicular veins: embryological and clinical considerations

Variations of the bilateral testicular veins were observed during routine dissection of the posterior abdominal wall in a 77-year-old male Japanese cadaver. The right testicular vein consisted of the lateral and medial testicular veins. The right lateral testicular vein drained into the right renal vein. The right medial testicular vein accompanied the right testicular artery to ascend obliquely and drained into the left aspect of the inferior vena cava. The left testicular vein was composed of the lateral, middle and medial testicular veins. Three left testicular veins accompanied the left testicular artery to course cranially and then finally drained into the left renal vein.     

胎儿和新生儿肾上腺的血管构筑

本文采用血管复型扫描电镜,注射墨汁切片光镜下观察和注射铅丹乳胶X线照像3种方法,研究了28例胎儿和新生儿肾上腺的血管构筑。发自膈下动脉、腹主动脉和肾动脉的肾上腺上、中、下动脉及其分支,在肾上腺囊表面和穿过囊的过程中逐级分支,最后形成毛细血管。动脉和毛细血管共同构成囊血管丛,从该丛发出的皮质动脉和髓质动脉,分别分支供给皮质和髓质。从囊血管丛发出的“V”型动脉在皮质中行一段距离后又返回囊中分支。永久性皮质毛细血管网是囊毛细血管的直接延续。在胎儿性皮质中,毛细血管有两个来源,其一是永久性皮质毛细血管的延伸;另一来源是由皮质动脉分支构成。它们共同构成胎儿性皮质毛细血管网。在胎儿性皮质的中部,毛细血管汇成小静脉。中央区的髓质由髓质动脉供血。在皮质中,正在迁移的髓质细胞团由与之伴行的动脉供应。在皮质中形成的小静脉呈向心性行走。其中一部分在近中央区又分为毛细血管,这些毛细血管相互吻合,最后入中央静脉的属支中。这种分布特点属于门脉形式的血管;另一部分属于中央静脉的第一级属支,它们逐级汇合后形成中央静脉主干。中央静脉系呈树枝状,其主干在腺的前面穿出腺后为肾上腺静脉。左侧肾上腺静脉人左肾静脉;右侧的人下腔静脉。而与动脉伴行的肾上腺上、中、下静脉的末级属支与囊毛细血管相连。本研究讨论了胎儿和新生儿肾上腺血管的分布规律,为胎儿内分泌学和肾上腺移植等方面提供了血管形态学基础。     

64层螺旋CT三维重建活体肝静脉的研究及临床意义

目的:探讨64层螺旋CT应用于正常人活体体肝静脉研究的可行性,观察三维重建肝静脉的一般形态及走行规律.方法:153例正常受试者经肘正中静脉注射造影剂后,使用64层螺旋CT进行上腹部扫描,图像采集后经容积再现(volume rendering,VR)技术重建肝静脉.结果:重建图像清晰,可显示出6～8级血管及与周围组织间的关系.其中153例肝静脉的分型结果如下:①3分支型,占35.3%(54例);②中左共干型,占41.8%(64例);③中左合干型,占20.9%(32例);④中右共干型,占2.0%(3例).结论:64层螺旋CT可以作为研究活体肝静脉形态的有效手段,三维重建能更准确、全方位地显示肝静脉的正常解剖类型和发现变异,而且图像清晰,对于活体肝静脉的研究有较好的临床应用价值.     

Infra‐renal angles,entry into inferior vena cava and vertebral levels of renal veins

Current norms for renal vasculature hold true in only half the population. Standard textbooks perpetuate old misconceptions regarding renal venous anatomy. This study is aimed to determine left and right infra‐renal angles (L‐IRA, R‐IRA); entry level of renal veins into the inferior vena cava (IVC), and height of IVC under renal vein influence; and their vertebral level. One hundred morphologically normal en‐bloc renal specimens randomly selected from post‐mortem examinations were dissected and resin casted. IRA were also measured from venograms of 32 adult and 11 foetal cadavers, as were vertebral entry levels. IRA measurements (degrees) were as follows: left, 55° ± 16° (20°–102°); right, 60° ± 17° (10°–93°). Left vein entered IVC higher than right 54%, lower 36%, and opposite each other 10%. Vertical distance between lower borders of veins was 1.0 ± 0.9 cm. Vertical distance of IVC under renal vein influence was 2.3 ± 1.0 cm. Vertebral level of veins in adults lies between TI2–L2. In foetuses, IRA was as follows: left, 65° ± 12° (45°–90°); right, 58° ± 7° (40°–70°); vertebral level between T12 and L3. Similar IRA values from literature noted on right, 51° (26°–100°); differences on left, 77° (43° –94°), clearly differing from Williams et al. (Gray's Anatomy, 37^th ed, 1989) statement that renal veins “open into the inferior vena cava almost at right angles.” Large variations of IRA are not surprising since kidneys are considered normally “floating viscera,” varying position with posture and respiratory movement as well as in live vs. cadaveric subjects. The entry level into the IVC also differs from Williams et al. This study uniquely quantitated actual height difference between lower borders of left and right veins. The data presented appears to be the first documentation of vertebral level of entry of renal veins into IVC in foetuses. These findings are clinically important for the angiographer, catheter design, and planning porto‐renal shunt procedures. Anat Rec 256:202–207, 1999. © 1999 Wiley‐Liss, Inc.     

The hepatic veins: Anatomy and classification on single slice spiral CT in North Indian population

AimsTo find out the normal pattern of hepatic veins in the North Indian population and to categorize them.MethodsThe present study was conducted on 100 patients whose spiral CT abdomen was performed for various medical conditions in the department of radiodiagnosis.ResultsFour categories were recognized. Category-1, when right hepatic vein drains independently into the inferior vena cava whereas middle and left hepatic veins join together to form a common trunk before draining into the inferior vena cava. It was observed in 74% patients. Category-2 was observed in 2% patients, where right & middle hepatic veins join to form a common trunk and left hepatic vein drain independently into the inferior vena cava. Category-3 was observed in 21% patients, where all the three major hepatic veins drain independently into the inferior vena cava. Category-4 was observed in 3% patients, where all the three major hepatic veins join together to form a common trunk before draining into the inferior vena cava.ConclusionsCategory-1 is the most common pattern of major hepatic vein drainage found in the North Indian population. The present study also concluded that single right, middle and left hepatic vein is the most common pattern of hepatic veins present in the North Indian population. Caudate lobe is drained by more than one vein in majority of North Indians. Also superomedial vein, right accessory vein and inferior right hepatic vein are the most common accessory veins present in the North Indian population.