Shinya Sonobe

Objectives: Operative time prediction is crucial for efficient operating room scheduling. This study developed and validated an operative time prediction system for robot‐assisted laparoscopic radical prostatectomy using data from two institutions. Methods: Retrospectively identified 557 and 150 patients who underwent RARP at Tohoku University Hospital and Miyagi Cancer Center were analyzed. The following variables were collected as explanatory variables for the prediction system: Age, height, body mass index, comorbidities, performance status, prostate volume, tumor extent of local invasion, grade group, prostatitis, preoperative treatment, history of intraperitoneal surgery, lymphadenectomy, and nerve‐sparing. In addition, the observed operative time was collected as a source variable for the objective variable. The observed operative time was calculated as the sum of components related to institutional, operator, and patient factors. Approximation curves were applied to the first two components, while a random forest‐based machine learning model was applied to the latter, resulting in the development of an integrated prediction system. Results: The normalized root mean square error between the observed and predicted operative times was 0.107 in internal validation and 0.148 in external validation, demonstrating greater reliability than the expected operative time by operators in advance. Factors that are known to impact operative time, such as lymphadenectomy, grade group, prostate volume, and body mass index, were identified as contributing variables. Conclusions: The system provides a reliable and robust prediction focusing on factors known to impact operative time. It has the potential to improve the efficiency of operating room scheduling.

We report a rare case of a vertebro-vertebral arteriovenous fistula (VVAVF) manifesting as amyotrophic lateral sclerosis (ALS). A 76-year-old female patient presented with progressive weakness, muscle atrophy, fasciculation, and preserved deep tendon reflexes in the right upper limb. Electrophysiological testing showed lower motor neuron dysfunction. The patient was suspected to have ALS, but cervical magnetic resonance imaging (MRI) revealed enlarged blood vessels in the spinal canal, which compressed the cervical spinal cord and nerve roots. Angiography showed a shunt from the right vertebral artery to the right intervertebral vein and the vertebral venous plexus; therefore, the patient was diagnosed with VVAVF. Transarterial embolization was performed to obliterate the shunt, and weakness in the patient’s right upper limb subsequently improved. It is worth considering VVAVF as a differential diagnosis of ALS-like diseases.

We report a rare case of a vertebro-vertebral arteriovenous fistula (VVAVF) manifesting as amyotrophic lateral sclerosis (ALS). A 76-year-old female patient presented with progressive weakness, muscle atrophy, fasciculation, and preserved deep tendon reflexes in the right upper limb. Electrophysiological testing showed lower motor neuron dysfunction. The patient was suspected to have ALS, but cervical magnetic resonance imaging (MRI) revealed enlarged blood vessels in the spinal canal, which compressed the cervical spinal cord and nerve roots. Angiography showed a shunt from the right vertebral artery to the right intervertebral vein and the vertebral venous plexus; therefore, the patient was diagnosed with VVAVF. Transarterial embolization was performed to obliterate the shunt, and weakness in the patient’s right upper limb subsequently improved. It is worth considering VVAVF as a differential diagnosis of ALS-like diseases.

We report a rare case of a vertebro-vertebral arteriovenous fistula (VVAVF) manifesting as amyotrophic lateral sclerosis (ALS). A 76-year-old female patient presented with progressive weakness, muscle atrophy, fasciculation, and preserved deep tendon reflexes in the right upper limb. Electrophysiological testing showed lower motor neuron dysfunction. The patient was suspected to have ALS, but cervical magnetic resonance imaging (MRI) revealed enlarged blood vessels in the spinal canal, which compressed the cervical spinal cord and nerve roots. Angiography showed a shunt from the right vertebral artery to the right intervertebral vein and the vertebral venous plexus; therefore, the patient was diagnosed with VVAVF. Transarterial embolization was performed to obliterate the shunt, and weakness in the patient’s right upper limb subsequently improved. It is worth considering VVAVF as a differential diagnosis of ALS-like diseases.

Oculomotor nerve palsy (ONP) may be caused by compression of the oculomotor nerve by the internal carotid artery-posterior communicating artery aneurysm (IC-PC AN) and/or basilar artery-superior cerebellar artery aneurysm (BA-SCA AN). During clipping, the oculomotor nerve can be observed directly and decompressed. However, the positional relationship between the aneurysm and oculomotor nerve is difficult to evaluate during intra-aneurysmal embolization. Constructive interference in steady state (CISS) allows detailed study of blood vessels and nerves in subarachnoid cisterns with high resolution. We herein report two cases of cerebral aneurysms presenting with ONP that were anatomically evaluated using CISS. Case 1 involved an 81-year-old woman who presented with a severe headache. She had no other neurological deficits. Computed tomography (CT) showed subarachnoid hemorrhage, while cerebral angiography revealed a left BA-SCA AN. Intra-aneurysmal embolization was performed; the framing coil spread throughout the aneurysm, and the other coils were placed using the Russian doll technique. The volume embolization rate was 43.4%. The following day, she developed left ONP. CISS on the 10th postoperative day revealed that the aneurysm was in contact with the left oculomotor nerve. The patient’s ONP gradually improved although the recovery was partial. Case 2 involved a 62-year-old woman who presented with a headache and subsequent right ONP. CT showed no subarachnoid hemorrhage, and cerebral angiography revealed the right IC-PC AN with a posterolateral projection. The aneurysm was constricted in the middle portion. CISS visualized that the right oculomotor nerve spanned along with the constriction. Intra-aneurysmal embolization was performed; the aneurysm was compartmentalized with the segment around the apex and the neck and embolized in each segment intentionally by the double-catheter technique while preventing damage to the oculomotor nerve. The volume embolization rate was 44.0%. The patient’s ONP steadily improved, and she fully recovered 1 year later. In endovascular treatment, anatomical information regarding structures around blood vessels is challenging to comprehend. CISS may be helpful for the evaluation of the surrounding structures. Utilizing information from CISS for endovascular treatment remains a challenge for the future.