Carbon dioxide-enhanced virtual MDCT cholangiopancreatography. J Hepatobiliary Pancreat Sci. 2010;17:601-610. [PMID: 19806296 DOI: 10.1007/s00534-009-0201-8]

Survey of preoperative management protocol for perihilar cholangiocarcinoma at 10 Japanese high-volume centers with a combined experience of 2,778 cases

BACKGROUND

In Japan, strategies for preoperative management of perihilar cholangiocarcinoma (PHC) have evolved over the last decade; the operative mortality has significantly reduced to <5%.

METHODS

A questionnaire was sent to 10 institutions based on their case volume. Questionnaire was based on: (1) preoperative biliary drainage, (2) bile replacement, (3) role of synbiotics, (4) remnant liver volume enhancement, (5) predicted remnant liver function, (6) imaging, (7) nutrition, and (8) role of Inchinkoto.

RESULTS

The median case volume was 226 (range 105-889) cases, respectively. Eight institutions preferred endoscopic nasobiliary drainage and two preferred endoscopic biliary stenting for biliary drainage. Nine used bile replacement within 2-3 days of biliary drainage. Four used synbiotics preoperatively. The median cutoff value for future remnant liver volume and serum total bilirubin, at which portal vein embolization (PVE) is done, is <40% and <4 mg/dl. The median interval between PVE and surgery was 3-4 weeks. To predict remnant liver function, indocyanine green retention (n = 8) and clearance rate (n = 2) were mainly used. Five used Inchinkoto to improve liver function. Nine used multidetector computed tomography and direct cholangiography for surgical planning.

CONCLUSION

With appropriate preoperative management of PHC, surgical morbidity and mortality can be reduced. This survey can provide recommendations to improve PHC perioperative outcomes.

Use of carbon dioxide as an intravascular contrast agent: A review of current literature

Use of X-ray contrast allows us to differentiate between two or more adjacent structures on radiographic studies. The X-ray contrast agent can be the one with increase X-ray absorption, like iodine and a barium X-ray contrast agent or the one with decrease X-ray absorption like air and carbon dioxide contrast agent. Each contrast agent possesses different risks and benefits in various ways. Carbon dioxide as an intravascular contrast agent can be used as an alternative intravascular contrast agent and has superior results in some cases. In patients with renal dysfunction or iodinated contrast allergy, the use of Iodinated Contrast Agent poses the risk of considerable morbidity. Similarly, use of Gadolinium is discouraged in subject with severe renal dysfunction. Use of carbon dioxide (CO₂) as an intravascular contrast, offers an alternative in such patients for certain procedures, as it is not nephrotoxic and it does not incite allergic reactions. It is inexpensive, readily available and due to its unique physical properties, it can be used to image a wide variety of vascular beds and chambers. The aim of this paper is to systemically review the current literature to describe the indications, contraindications, adverse effects, instruments, precautions, latest methodologies and data supporting for the use of CO₂ as a contrast agent.

Mediastinal pulmonary artery is associated with greater artery diameter and lingular division volume

Pulmonary vessels have numerous variation and aberrant branching patterns. Mediastinal lingular artery (MLA), the most common aberrant branch, might contribute to greater blood flow to lingular division. Hence, we investigated a correlation between lingular division volume and MLA using three-dimensional CT volumetry. We included 199 consecutive patients who underwent surveillance chest CT to detect possible malignancies in April 2015. We measured lingular division volume and cross-sectional area of lingular arteries using three-dimensional CT volumetry. MLA was identified in 58 cases (29.1%). The MLA group had significantly greater lingular division volume (median ± quartile deviation: 378.3 ± 75.5 mL vs. 330.0 ± 87.5 mL; p = 0.021) and percentage lingular division to left lung volume (19.0 ± 2.62% vs. 16.6 ± 2.39%; p < 0.001) than the non-MLA group. Total cross-sectional area of lingular arteries of the MLA group was significantly larger than that of the non-MLA group (46.1 ± 9.46 vs. 40.2 ± 5.76 mm²; p = 0.003). The total cross-sectional area of the lingular arteries strongly correlated to the percentage of lingular division to left lung volume (r = 0.689, p < 0.001). This is the first report demonstrating a positive correlation between branching pattern of pulmonary artery and lung volume.

Three-Dimensional Liver Surgery Simulation: Computer-Assisted Surgical Planning with Three-Dimensional Simulation Software and Three-Dimensional Printing<sup/>

To perform accurate hepatectomy without injury, it is necessary to understand the anatomical relationship among the branches of Glisson's sheath, hepatic veins, and tumor. In Japan, three-dimensional (3D) preoperative simulation for liver surgery is becoming increasingly common, and liver 3D modeling and 3D hepatectomy simulation by 3D analysis software for liver surgery have been covered by universal healthcare insurance since 2012. Herein, we review the history of virtual hepatectomy using computer-assisted surgery (CAS) and our research to date, and we discuss the future prospects of CAS. We have used the SYNAPSE VINCENT medical imaging system (Fujifilm Medical, Tokyo, Japan) for 3D visualization and virtual resection of the liver since 2010. We developed a novel fusion imaging technique combining 3D computed tomography (CT) with magnetic resonance imaging (MRI). The fusion image enables us to easily visualize anatomic relationships among the hepatic arteries, portal veins, bile duct, and tumor in the hepatic hilum. In 2013, we developed an original software, called Liversim, which enables real-time deformation of the liver using physical simulation, and a randomized control trial has recently been conducted to evaluate the use of Liversim and SYNAPSE VINCENT for preoperative simulation and planning. Furthermore, we developed a novel hollow 3D-printed liver model whose surface is covered with frames. This model is useful for safe liver resection, has better visibility, and the production cost is reduced to one-third of a previous model. Preoperative simulation and navigation with CAS in liver resection are expected to help planning and conducting a surgery and surgical education. Thus, a novel CAS system will contribute to not only the performance of reliable hepatectomy but also to surgical education.

Carbon dioxide contrast medium for endovascular treatment of ilio-femoral occlusive disease

OBJECTIVES

Compare the use of carbon dioxide contrast medium with iodine contrast medium for the endovascular treatment of ilio-femoral occlusive disease in patients without contraindications to iodine.

MATERIALS AND METHODS

From August 2012 to August 2014, 21 consecutive patients with ilio-femoral occlusive disease who were eligible for endovascular treatment and lacked contraindications to either iodine contrast or carbon dioxide were randomized into the carbon dioxide or iodine groups and subjected to ilio-femoral angioplasty.We analyzed the feasibility of the procedures, the surgical and clinical outcomes, the procedure lengths, the endovascular material costs, the contrast costs and the quality of the angiographic images in each group.

RESULTS

No conversions to open surgery and no contrast media related complications were noted in either group. A post-operative femoral pulse was present in 88.9% of the iodine group and 80% of the carbon dioxide group. No differences in procedure length, endovascular material cost or renal function variation were noted between the groups. Four patients in the carbon dioxide group required iodine supplementation to complete the procedure. Contrast media expenses were reduced in the carbon dioxide group. Regarding angiographic image quality, 82% of the carbon dioxide images were graded as either good or fair by observers.

CONCLUSIONS

The use of carbon dioxide contrast medium is a good option for ilio-femoral angioplasty in patients without contraindications to iodine and is not characterized by differences in endovascular material costs, procedure duration and surgical outcomes. In addition, carbon dioxide has lower contrast expenses compared with iodine.

Usefulness of operative planning based on 3-dimensional CT cholangiography for biliary malignancies

BACKGROUND

The complexity of hepatic hilar anatomy is an obstacle to precise diagnosis of tumor spread and appropriate operative planning for biliary malignancies. Three-dimensional (3D) cholangiography and angiography may overcome this obstacle and facilitate curative resection. The objective of this study was to evaluate the impact of 3D CT cholangiography on operative planning and outcomes of biliary malignancies.

METHODS

From 2009 to 2014, 3DCT cholangiography was performed on 49 patients with biliary malignancies requiring major hepatic resection and extrahepatic bile duct resection. The 3D cholangiogram was merged with 3D angiography and portography to create an all-in-one 3D image of the hepatic hilum. The cutting line of the bile duct and the type of liver resection were determined based on the spatial relationship between tumor spread and the landmark vessels. The necessity of vascular reconstruction was also evaluated. Preoperative imaging and operative findings were compared. Operative curability was compared with that of the historical cohort before the introduction of 3D cholangiography.

RESULTS

Histologic examination of the bile duct stump showed a negative margin in 39 (80%), carcinoma in situ in 7 (14%), and invasive cancer (IC) in 3 patients (6%) on the first cutting. The IC-free rate (94%) on the first cutting was superior to that in the historical cohort (80%; P = .02). The necessity for portal and arterial reconstruction was predicted with 98 and 94% accuracy, respectively.

CONCLUSION

We found 3D cholangiography to provide accurate information about hilar anatomy and plays a role in facilitating adequate operative planning.

An integrated teaching method of gross anatomy and computed tomography radiology

It is essential for medical students to learn and comprehend human anatomy in three dimensions (3D). With this in mind, a new system was designed in order to integrate anatomical dissections with diagnostic computed tomography (CT) radiology. Cadavers were scanned by CT scanners, and students then consulted the postmortem CT images during cadaver dissection to gain a better understanding of 3D human anatomy and diagnostic radiology. Students used handheld digital imaging and communications in medicine viewers at the bench-side (OsiriX on iPod touch or iPad), which enabled "pixel-to-tissue" direct comparisons of CT images and cadavers. Students had lectures and workshops on diagnostic radiology, and they completed study assignments where they discussed findings in the anatomy laboratory compared with CT radiology findings. This teaching method for gross and radiological anatomy was used beginning in 2009, and it yielded strongly positive student perspectives and significant improvements in radiology skills in later clinical courses.

Carbon dioxide insufflation for endoscopic retrograde cholangiopancreatography: A meta-analysis and systematic review

AIM

To assess the safety and efficacy of carbon dioxide (CO(2)) insufflation during endoscopic retrograde cholangiopancreatography (ERCP).

METHODS

The Cochrane Library, Medical Literature Analysis and Retrieval System Online, Excerpta Medica Database, Science Citation Index Expanded, Chinese Biomedical Literature Database, and references in relevant publications were searched up to December 2011 to identify randomized controlled trials (RCTs) comparing CO(2) insufflation with air insufflation during ERCP. The trials were included in the review irrespective of sample size, publication status, or language. Study selection and data extraction were performed by two independent authors. The meta-analysis was performed using Review Manager 5.1.6. A random-effects model was used to analyze various outcomes. Sensitivity and subgroup analyses were performed if necessary.

RESULTS

Seven double-blind RCTs involving a total of 818 patients were identified that compared CO(2) insufflation (n = 404) with air insufflation (n = 401) during ERCP. There were a total of 13 post-randomization dropouts in four RCTs. Six RCTs had a high risk of bias and one had a low risk of bias. None of the RCTs reported any severe gas-related adverse events in either group. A meta-analysis of 5 RCTs (n = 459) indicated that patients in the CO(2) insufflation group had less post-ERCP abdominal pain and distension for at least 1 h compared with patients in the air insufflation group. There were no significant differences in mild cardiopulmonary complications [risk ratio (RR) = 0.43, 95% CI: 0.07-2.66, P = 0.36], cardiopulmonary (e.g., blood CO(2) level) changes [standardized mean difference (SMD) = -0.97, 95% CI: -2.58-0.63, P = 0.23], cost analysis (mean difference = 3.14, 95% CI: -14.57-20.85, P = 0.73), and total procedure time (SMD = -0.05, 95% CI: -0.26-0.17, P = 0.67) between the two groups.

CONCLUSION

CO(2) insufflation during ERCP appears to be safe and reduces post-ERCP abdominal pain and discomfort.

Three-dimensional reconstructed computed tomography-magnetic resonance fusion image-based preoperative planning for surgical procedures for spinal lipoma or tethered spinal cord after myelomeningocele repair

Surgical procedures for spinal lipoma or tethered spinal cord after myelomeningocele (MMC) repair are often difficult and complicated, because the anatomical structures can be deformed in complex and unpredictable ways. Imaging helps the surgeon understand the patient's spinal anatomy. Whereas two-dimensional images provide only limited information for surgical planning, three-dimensional (3D) reconstructed computed tomography (CT)-magnetic resonance (MR) fusion images produce clearer representations of the spinal regions. Here we describe simple and quick methods for obtaining 3D reconstructed CT-MR fusion images for preoperative planning of surgical procedures using the iPlan(®) cranial (BrainLAB AG, Feldkirchen, Germany) neuronavigation software. 3D CT images of the vertebral bone were combined with heavily T(2)-weighted MR images of the spinal cord, lipoma, cerebrospinal fluid (CSF) space, and nerve root through a process of fusion, segmentation, and reconstruction of the 3D images. We also used our procedure called "Image Overlay" to directly project the 3D reconstructed image onto the body surface using an LED projector. The final reconstructed 3D images took 10-30 minutes to obtain, and provided the surgeon with a representation of the individual pathological structures, so enabled the design of effective surgical plans, even in patients with bony deformity such as scoliosis. None of the 19 patients treated based on our 3D reconstruction method has had neurological complications, except for CSF leakage. This 3D reconstructed imaging method, combined with Image Overlay, improves the visual understanding of complicated surgical situations, and should improve surgical efficiency and outcome.