Mika Kamiya

Analysis of intrahepatic venovenous shunt by hepatic venography

BACKGROUND The necessity of preserving hepatic venous drainage in hepatectomy and liver transplantation has recently been accepted; however, the hepatic vein (HV) can be removed when an effective intrahepatic venovenous shunt (VV shunt) exists. METHODS Occlusion venography of the right HV (RHV) was performed in 51 patients to investigate the VV shunt characteristics. RESULTS Twenty patients had a shunt between the RHV and large HVs whose root diameters were >3 mm, such as the superficial or inferior RHV, or the middle HV. Twenty patients had a shunt between the RHV and small HVs with root diameters < or =3 mm. Eleven patients had no shunt. The change in anterior portal vein blood flow after RHV occlusion, evaluated by Doppler ultrasonography, was minimal (5 +/- 3%) in patients with a shunt between the RHV and large HVs, and less than in patients with a shunt between the RHV and small HVs (38% +/- 18%) or without a shunt (50% +/- 17%; P < .0001). A shunt between the RHV and large HV was less frequently seen in those patients with cirrhosis (3/20) than in those without cirrhosis (17/31; P = .0044). The existence of the shunt between the RHV and large HVs was unpredictable, however, from computed tomographic findings or laboratory data. CONCLUSION A hemodynamically significant VV shunt between the RHV and large HV was observed in fewer than half of the patients and less frequently in cirrhotic patients. Preservation of hepatic venous drainage should be considered in patients without a hemodynamically significant VV shunt in liver surgery.

Evaluation of tumor blood flow after feeder embolization in meningiomas by arterial spin-labeling perfusion magnetic resonance imaging.

Preoperative embolization changes the amount of blood flow and pattern of flow distribution in meningioma. Tumor blood flow was investigated in eight meningioma patients before and after embolization using arterial spin-labeling (ASL) perfusion imaging. Although blood flow was significantly reduced in the whole tumor after embolization, changes in flow distribution patterns varied from one case to another. The findings suggest that evaluation of post-embolization tumor blood flow by ASL perfusion imaging would be useful in the surgical planning of meningioma.

Anomalous arterial ramification in the right liver

PurposeThe aim of this study was to investigate whether individual arterial and portal venous division during hepatectomy is always safe by examining the presence of the anomalous arterial ramification in the right liver.MethodsThe ramifications of the right hepatic artery (RHA) were investigated by three-dimensional (3D) reconstruction imaging using a computer software program in 87 patients undergoing computed tomography during angiography as a preoperative assessment of intrahepatic tumors.ResultsThe anterior view showed that the RHA bifurcated into the anterior and posterior sector arteries at the hilum in 76 patients. Sector-intersecting arteries from the posterior to the anterior sector and vice versa were found in 7 and 4 of those patients, respectively. The RHA in the other 11 patients was divided in a complex manner into more than 2 arteries: e.g., the first branch to the cranial part of the posterior sector, the second to the anterior sector, and the third to the caudal part of the posterior sector. A total of 22 patients showed anomalous ramification of RHA.ConclusionPreoperative observation of the hepatic artery by 3D imaging is very useful to detect anomalous ramification. Arterial dissection during the intrafascial approach should be cautiously performed based on the 3D images.

Hemorrhagic radiation gastritis successfully treated with repeated intra-arterial steroid infusions

Intra-arterial steroid infusion therapy has previously been shown to be effective for inflammatory bowel disease; however, few cases in which it has been used for the treatment of hemorrhagic radiation gastritis have been reported. We report the case of a 70-year-old Japanese man with hemorrhagic radiation gastritis induced by radiation therapy for para-aortic lymph node metastases of hepatocellular carcinoma. Two months after completing radiation therapy, acute persistent bleeding occurred in the gastric irradiation area. Although argon plasma coagulation was performed five times over a month, the bleeding continued and the patient showed persistent anemia that required 50 units of blood transfusion. Finally, the patient was given intra-arterial steroid infusions through the right gastric artery and the right gastroepiploic artery. After three intra-arterial steroid infusions, the melena stopped, and the anemia no longer progressed. Hemorrhagic radiation gastritis was successfully treated with repeated intra-arterial steroid infusions through the regional vessels to the gastric mucosa. Repeated intra-arterial steroid infusions could be a clinically useful option for the treatment of intractable bleeding from radiation gastritis.

Cerebellar Hemorrhage due to a Direct Carotid-Cavernous Fistula after Surgery for Maxillary Cancer.

Infratentorial cerebral hemorrhage due to a direct carotid–cavernous fistula (CCF) is very rare. To our knowledge, only four such cases have been reported. Cerebellar hemorrhage due to a direct CCF has not been reported. We describe a 63-year-old female who presented with reduced consciousness 3 days after undergoing a maxillectomy for maxillary cancer. Computed tomography showed a cerebellar hemorrhage. Magnetic resonance angiography showed a left-sided direct CCF draining into the left petrosal and cerebellar veins through the left superior petrosal sinus (SPS). Her previous surgery had sacrificed the pterygoid plexus and facial vein. Increased blood flow and reduced drainage could have led to increased venous pressure in infratentorial veins, including the petrosal and cerebellar veins. The cavernous sinus has several drainage routes, but the SPS is one of the most important routes for infratentorial venous drainage. Stenosis or absence of the posterior segment of the SPS can also result in increased pressure in the cerebellar and pontine veins. We emphasize that a direct CCF with cortical venous reflux should be precisely evaluated to determine the hemodynamic status and venous drainage from the cavernous sinus.

Transvenous Embolization of a Dural Arteriovenous Fistula Involving the Suboccipital Cavernous Sinus

Arnautovic et al. [1] termed the venous structures surrounding the extraspinal segment of the vertebral artery (VA; V3) the suboccipital cavernous sinus (SCS) [1, 4]. We experienced a rare dural arteriovenous fistula (AVF) involving the SCS, which differed from dural AVFs involving the anterior condylar confluence (ACC). Here we present a case of SCS dural AVF with pulsatile tinnitus treated by transvenous embolization (TVE).

Dural Arteriovenous Fistula of the Transverse and Sigmoid Sinus Manifesting Ascending Dysesthesia: Case Report and Literature Review

Cases involving intracranial dural arteriovenous fistulas (AVFs) with spinal perimedullary venous drainage exhibit variable presentations, which results in delayed diagnoses. We describe a case of a 66-year-old female with a transverse-sigmoid sinus dural AVF with spinal perimedullary venous drainage who developed dysesthesia and hypalgesia that ascended from the peripheral lower extremities. Sixty cases of intracranial dural AVFs resulting in myelopathy have been reported, and an absence of brainstem signs significantly correlated with a delay in diagnosis (positive group: 3.4 months vs. negative group: 9.6 months, P < 0.05). Intracranial dural AVFs with brainstem signs should be diagnosed without delay because the myelopathy and bulbar symptoms could progress aggressively without alternative drainage routes besides the perimedullary veins. We emphasize that intracranial dural AVFs should be considered as a differential diagnosis in case presenting with symptoms, such as atypical dysesthesia and hypalgesia ascending from the toes, without brainstem signs. Moreover, we should perform cerebral angiography as early as possible because dural AVFs with slow-flow venous drainage can produce false negatives on magnetic resonance angiography.