Aberrant left gastric vein demonstrated by helical CT

Aberrant gastric venous drainage and associated atrophy of hepatic segment II: computed tomography analysis of 2021 patients

PURPOSE

To investigate the prevalence and patterns of aberrant gastric venous drainage and associated atrophy of the hepatic segment on contrast-enhanced computed tomography (CT).

METHODS

Two radiologists retrospectively reviewed contrast-enhanced CT images from 2021 patients who underwent cone-beam CT-guided chemoembolization between January 2013 and December 2018. They determined the presence or absence of an aberrant gastric vein(s) and its drainage site by consensus, and qualitatively analyzed the presence or absence of atrophy of segments II or III. In cases of disagreement between the two reviewers regarding the presence of atrophy, quantitative analysis was performed using dedicated software.

RESULTS

A total of 31 aberrant right gastric veins were revealed on CT (1.5%), most of which drained into P2 (n = 8), the S2/3 border zone (n = 8), S2 (n = 6), or S4 (n = 5). An aberrant left gastric vein was observed in 21 (1.0%) patients, and P2 was the most common drainage site (n = 13) in these patients. Atrophy of segment II was more frequently observed among patients with aberrant gastric veins than among those without (26.9% versus 4.1%; p < 0.001). In addition, an aberrant gastric vein draining into P2 was most frequently accompanied by segment II atrophy (47.6%).

CONCLUSION

Aberrant right and left gastric veins were observed in 1.5% and 1.0% of patients, respectively. Atrophy of segment II was frequently observed in patients with aberrant gastric veins, especially those that drained into P2.

Aberrant left gastric vein is associated with hepatic artery variations

OBJECTIVE

To investigate the imaging findings and hepatic artery variations encountered in patients with aberrant left gastric vein (ALGV).

METHODS

A retrospective database search between January 2014 and November 2018 was carried for ALGV. The course and types (1-3) of ALGV, the presence of associated liver lesions, and coexistence of hepatic artery variations were reviewed on CT images.

RESULTS

A total of 32 patients (22 men, 68.7%) with a mean age of 52.5 years (range 22-76 years) were found to have ALGV. The prevalence of ALGV was 0.073%. The most frequent type of ALGV was type 1 (n = 22, 68.7%), followed by type 3 (n = 7, 21.8%) and type 2 (n = 3, 9.3%). We noticed mild-to-severe parenchymal hyperdensity at the posterior aspect of segments II and III in patients with type 1 (n = 20/22) and type 2 (n = 2/3) ALGV consistent with fat sparing due to third inflow effect. Two out of seven patients with type 3 ALGV had main portal vein thrombosis; however, the presence of ALGV maintained left portal vein flow in these patients. Twelve (37.5%) patients had accompanying hepatic artery variation. Left hepatic and right hepatic artery variations were detected in 8 (25%) and 2 (6.25%) of the patients, respectively. In 2 patients, Michels type IV variation was detected.

CONCLUSION

Aberrant left gastric vein is associated with hepatic artery variations, which can be important for preoperative and pretransplant planning.

Left gastric vein on the dorsal side of the splenic artery: a rare anatomic variant revealed during gastric surgery

Purpose

The left gastric vein (LGV) is an important blood vessel requiring dissection during gastric surgery. We describe a rare anatomic variant of the LGV.

Methods

The LGV drainage pattern was analyzed relative to intraoperative vascular anatomy in 2,111 patients with gastric cancer who underwent radical resection from May 2007 to September 2012. The incidence of the anatomic variant was determined, and the diameter and length of the LGV and the distances from the end of the LGV to the splenoportal confluence and the root of the left gastric artery (LGA) were measured by abdominal CT reconstruction.

Results

In 6 of the 2,111 (0.28 %) gastric cancer patients who underwent radical resection, the LGV descended on the left side of the gastropancreatic fold, ran across the dorsal side of the splenic artery and drained into the splenic vein. The mean diameter and length of the LGV were 5.10 ± 0.40 and 37.40 ± 5.19 mm, respectively, and the mean distance from the end of the LGV to the splenoportal confluence was 13.05 ± 0.86 mm. The closer the LGV and LGA were to the root, the greater the distance between them, with a mean 13.85 ± 1.02 mm between the end of the LGV and the root of the LGA.

Conclusions

In this rare anatomic variant, the LGV descends along the gastropancreatic fold, runs across the dorsal side of the splenic artery and drains into the splenic vein. Knowledge of this rare anatomic variant will help avoid damage to the LGV during gastric surgery.

Accessory Left Gastric Artery from Left Hepatic Artery Shown on MDCT and Conventional Angiography: Correlation with CT Hepatic Arteriography

OBJECTIVE

The objective of our study was to evaluate the diagnostic accuracy of MDCT and conventional angiography in the detection of an accessory left gastric artery using CT hepatic arteriography as the standard of reference.

MATERIALS AND METHODS

The study group consisted of 118 patients who underwent MDCT with a triple-phase liver protocol with a slice thickness of 5 mm, conventional angiography, and CT hepatic arteriography. The early-phase images of MDCT and conventional angiography were retrospectively reviewed. The presence or absence of an accessory left gastric artery was evaluated using CT hepatic arteriography as the standard of reference. The sensitivity, specificity, and accuracy of MDCT and conventional angiography were calculated.

RESULTS

CT hepatic arteriography revealed an accessory left gastric artery in 25 (21.2%) of 118 cases, including 15 proximal- and 10 distal-type accessory left gastric arteries. On MDCT, there were seven false-negative cases and one false-positive case. Six of the seven false-negative cases were a proximal-type accessory left gastric artery, and nine of 10 distal-type accessory left gastric arteries were correctly diagnosed using MDCT. The sensitivity, specificity, and accuracy of MDCT were 72.0%, 98.9%, and 93.2%, respectively. On conventional angiography, there were three false-negative and two false-positive cases, none of whom underwent selective left hepatic arteriography. Two of the three false-negative cases were the distal-type accessory left gastric artery, but eight of the 10 distal-type accessory left gastric arteries were correctly diagnosed. The sensitivity, specificity, and accuracy of conventional angiography were 88.0%, 97.8%, and 95.8%, respectively.

CONCLUSION

Approximately 70% of accessory left gastric arteries can be diagnosed at the early phase of MDCT even with a slice thickness of 5 mm.

Portal vein occlusion with aberrant left gastric vein functioning as a hepatopetal collateral pathway

A rare case of an aberrant left gastric vein functioning as a hepatopetal collateral as a result of portal vein occlusion is presented herein. The portal venous phase of multislice computed tomography clearly demonstrated this anatomic variation and provided a reliable vascular "road map" for percutaneous transhepatic portal venous stent placement. Portal hypertension associated with extensive gastrojejunal varices improved dramatically after stent placement.

Focal sparing of fatty liver in segment II associated with aberrant left gastric vein

We present a patient with aberrant left gastric vein (LGV) that directly enters the posterior edge of segment II in the liver. The corresponding area was focally spared of fatty liver. We consider that this aberrant LGV contributed to the cause of focal sparing. This is the first report of the use of helical CT and Doppler ultrasound to depict the aberrant LGV that directly enters the liver.

Current role of CT in imaging of the stomach

Recent advances in computed tomographic (CT) technology and three-dimensional (3D) imaging software have sparked renewed interest in using CT to evaluate gastric disease. Multidetector row CT scanners allow thinner collimation, which improves the visualization of subtle tumors as well as the quality of the 3D data sets. When water is used as an oral contrast agent, subtle disease is easier to visualize, especially when a rapid contrast material bolus is intravenously administered. Adenocarcinoma is the most common gastric malignancy and typically appears as focal or segmental wall thickening or a discrete mass. Gastric lymphoma can have a CT appearance similar to that of adenocarcinoma. Both gastric adenocarcinoma and lymphoma may be associated with adenopathy. Gastrointestinal stromal tumors (GISTs) tend to appear as well-defined masses that arise from the gastric wall and may be exophytic when large. GISTs are usually not associated with significant adenopathy. In addition to gastric malignancies, CT can also help detect inflammatory conditions of the stomach, including gastritis and peptic ulcer disease. CT angiography is especially helpful for depicting the gastric vasculature, which may be affected by a variety of disease conditions.

Transcatheter arterial chemoembolization for hepatocellular carcinoma: anatomic and hemodynamic considerations in the hepatic artery and portal vein

Hepatocellular carcinoma (HCC) is the most common malignant tumor of the liver. Although several therapeutic options have been advocated, transcatheter arterial chemoembolization (TACE) in particular has been widely performed in the treatment of HCC. Still, hepatic arteriography and portography are mandatory for evaluation of (a) the resectability and multiplicity of HCCs and (b) the hemodynamic status of the portal vein. Thereafter, TACE can be considered as the initial therapeutic modality. The possibility of nontarget organ complications during TACE (eg, ischemic cholecystitis, splenic infarction, gastrointestinal mucosal lesions, pulmonary embolism and infarction, spinal cord injury, ischemic skin lesions) should be taken seriously. A thorough understanding of the anatomic variants and hemodynamic features of the hepatic artery and portal vein is the first step in performing effective and safe TACE for HCC.

Intrahepatic portosystemic venous shunts: spectrum of CT findings in external and internal subtypes

PURPOSE

The purpose of this work was to survey the spectrum of CT findings in intrahepatic portosystemic venous shunts (IPSVSs).

METHOD

One thousand consecutive liver CT scans examined with an enhanced helical technique were retrospectively reviewed on workstation to find IPSVSs.

RESULTS

IPSVSs were noted in 37 patients and divided into two subtypes according to the location of the communicating systemic vein, either outside (external type, n = 34) or within (n = 4) the liver (one patient had both internal and external types). All the external-type shunts were noted in cases with portal hypertension (n = 34). Most shunts (n = 30) ran through segment 4 and/or 3 and came out near the falciform ligament, but five shunts were noted in segment 2 communicating either with the systemic vein (n = 3) or probably with an enlarged left gastric vein (n = 2). Solitary portohepatic venous shunts (internal type) were noted in three cases with (n = 2) or without (n = 1) aneurysmal dilatation and many portohepatic venous shunts in another patient.

CONCLUSION

IPSVSs of the external type were far common than those of the internal type, always associated with increased pressure of the portal system and in specific sites probably lacking the hepatic capsule.

Aberrant left gastric vein directly draining into the liver

An aberrant left gastric vein found in dissection is reported here. The right gastric vein did not exist and only the left gastric vein originating from the lesser curvature of the stomach was present. It directly entered the liver without typically joining the trunk of the portal vein. After giving off a small branch to the liver parenchyma, the left gastric vein merged into the left branch of the portal vein. This aberrant left gastric vein may correspond to the phylogenetic and ontogenetic "left portal vein." The aberrant left gastric vein is considered to play an important role as a portal collateral pathway of the portal system, which is critical not only in anatomy but also in clinical diagnosis.

Embryologic and anatomic basis of esophageal surgery

The embryogenesis, congenital anomalies, and surgical anatomy and applications of the esophagus for benign and malignant processes are detailed in this article. Emphasis is placed on the role of embryology and the anatomy involved in surgical decisions.