Identification of the aberrant hepatic artery with axial spiral CT

[Status Quo of Surgical Navigation]

Surgical navigation, also referred to as computer-assisted or image-guided surgery, is a technique that employs a variety of methods - such as 3D imaging, tracking systems, specialised software, and robotics to support surgeons during surgical interventions. These emerging technologies aim not only to enhance the accuracy and precision of surgical procedures, but also to enable less invasive approaches, with the objective of reducing complications and improving operative outcomes for patients. By harnessing the integration of emerging digital technologies, surgical navigation holds the promise of assisting complex procedures across various medical disciplines. In recent years, the field of surgical navigation has witnessed significant advances. Abdominal surgical navigation, particularly endoscopy, laparoscopic, and robot-assisted surgery, is currently undergoing a phase of rapid evolution. Emphases include image-guided navigation, instrument tracking, and the potential integration of augmented and mixed reality (AR, MR). This article will comprehensively delve into the latest developments in surgical navigation, spanning state-of-the-art intraoperative technologies like hyperspectral and fluorescent imaging, to the integration of preoperative radiological imaging within the intraoperative setting.

Does Aberrant Right Hepatic Artery Influence the Surgical Short- and Long-term Outcome of Pancreatoduodenectomy?

BACKGROUND

Variations in vascular anatomy in pancreaticoduodenectomy for adenocarcinoma of the pancreatic head, aberrant right hepatic artery (αRHA) being the most frequent, may influence oncological outcome, surgical complexity, intra- and postoperative complications, and overall 5-year disease-free and survival rates.

MATERIALS AND METHODS

Between January 1988 and January 2018, 297 consecutive patients underwent pancreaticoduodenectomy at our Institutions and were divided into two groups: Group 1 patients were affected with αRHA; group 2 were without this vascular anomaly. The groups were retrospectively compared to identify differences in preoperative characteristics and intraoperative course, postoperative morbidity and mortality and long-term disease-free interval and overall survival. Cox regression analysis was used to investigate the role of variables statistically significant at univariate analysis in the short- and long-term outcomes.

RESULTS

Overall 44 (15%) patients had αRHA. No differences in patient characteristics were reported. The mean operative time was 451±58 minutes for group 1 and 317±27 minutes for group 2 (p<0.001), whereas mean blood losses were 729±488 ml and 508±119 ml, respectively (p<0.001). Group 1 patients had a longer stay in intensive care when compared to patients of group 2 (mean 5±2 versus 4±2 days, respectively; p<0.001). Furthermore group 1 patients had a significant longer hospitalization when compared to those of group 2 (mean 17±5 versus 15±3 days, respectively; p<0.006). No other significant differences were observed between the two groups. Cox regression analysis showed that independently of the presence of αRHA, the factors negatively affecting the 5-year survival rate were blood loss (p<0.001) and length of stay in intensive care (p<0.001).

DISCUSSION

αRHA increases the surgical complexity of pancreatoduodenectomy, negatively affecting intraoperative blood loss, length of operation, length in intensive care and hospitalization, but does not influence long-term survival and disease-free rates.

Anatomical variations of the celiac trunk and hepatic arterial system: an analysis using multidetector computed tomography angiography

OBJECTIVE

To analyze the prevalence of anatomical variations of celiac arterial trunk (CAT) branches and hepatic arterial system (HAS), as well as the CAT diameter, length and distance to the superior mesenteric artery.

MATERIALS AND METHODS

Retrospective, cross-sectional and predominantly descriptive study based on the analysis of multidetector computed tomography images of 60 patients.

RESULTS

The celiac trunk anatomy was normal in 90% of cases. Hepatosplenic trunk was found in 8.3% of patients, and hepatogastric trunk in 1.7%. Variation of the HAS was observed in 21.7% of cases, including anomalous location of the right hepatic artery in 8.3% of cases, and of the left hepatic artery, in 5%. Also, cases of joint relocation of right and left hepatic arteries, and trifurcation of the proper hepatic artery were observed, respectively, in 3 (5%) and 2 (3.3%) patients. Mean length and caliber of the CAT were 2.3 cm and 0.8 cm, respectively. Mean distance between CAT and superior mesenteric artery was 1.2 cm (standard deviation = 4.08). A significant correlation was observed between CAT diameter and length, and CAT diameter and distance to superior mesenteric artery.

CONCLUSION

The pattern of CAT variations and diameter corroborate the majority of the literature data. However, this does not happen in relation to the HAS.

Accuracy of routine multidetector computed tomography to identify arterial variants in patients scheduled for pancreaticoduodenectomy

AIM: To assess the efficacy of cross-sectional multidetector computed tomography (MDCT) imaging without arterial reconstruction to identify aberrant right hepatic artery (RHA) and celiac artery stenosis (CAS) in patients scheduled for pancreaticoduodenectomy.

METHODS: Patients with peri-ampullary and pancreatic head tumors who underwent routine preoperative MDCT and subsequent computed tomography (CT) angiography (CTA), conventional angiography or pancreaticoduodenectomy between September 2007 and August 2013 were identified. Retrospective analysis of imaging data was undertaken using CTA, conventional angiographic and surgical findings as the reference standards. The accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of MDCT in evaluation of aberrant RHA and CAS were calculated.

RESULTS: A group of 458 patients met the inclusion criteria of this study to detect aberrant RHA, and 181 cases were included to identify CAS. Fifty-four (11.8%) patients were confirmed to have aberrant RHA, while 12 (6.6%) patients with CAS were demonstrated. MDCT yielded an accuracy of 98.5%, sensitivity of 96.3% and specificity of 98.8% in the detection of aberrant RHA. The sensitivity, specificity, PPV and NPV of MDCT for detecting CAS were 58.3%, 98.2%, 70% and 97.1%, respectively.

CONCLUSION: Routine MDCT is recommended such that surgeons and radiologists be alerted to the importance of arterial variants on preoperative CT scans in patients scheduled for pancreaticoduodenectomy.

The implications of the presence of an aberrant right hepatic artery in patients undergoing a pancreaticoduodenectomy

PURPOSE

An aberrant right hepatic artery (ARHA) is a common anomaly and its implications for patients undergoing a pancreaticoduodenectomy (PD) have not yet been previously reported. We compared the outcomes following PD in patients with and without an ARHA. A novel classification of the anatomical course of ARHA, and surgical techniques for its identification and preservation are described herein.

METHODS

All patients undergoing PD between June 1, 2002, and May 31, 2007, were divided into two groups, one with ARHA and the other without. These groups were compared to identify differences in the intraoperative variables, the oncological clearance, the postoperative complications, and the survival.

RESULTS

A total of 135 patients underwent PD of which 28 (20.8%) patients were found to have either accessory or replaced right hepatic arteries (ARHA group). There were no significant differences in the intraoperative variables (blood loss and operative time) and the incidence of postoperative complications (pancreatic leak and delayed gastric emptying). Oncological clearance (nodal yield and resection margins) and survival were also similar in the two groups.

CONCLUSIONS

The surgical and oncological outcomes of PD remain unaffected by the presence of ARHA provided that the anatomy is recognized and appropriately managed. Aberrant right hepatic artery can be classified into three types according to their anatomical relationship with the head of the pancreas.

Aberrant hepatic artery in patients undergoing pancreaticoduodenectomy

BACKGROUND

It is very important to keep the integrity of the hepatic artery blood supply in patients treated by pancreaticoduodenectomy. Knowing and identifying hepatic artery anomalies is helpful to avoid injuring them during the procedure of pancreaticoduodenectomy in patients with ampullary tumors (including cancer in the pancreatic head).

METHODS

Aberrant hepatic artery in patients with ampullary tumors was identified by multislice computed tomography (CT) and digital subtraction angiography (DSA) in our institute between April 2002 and June 2006. Clinical data of patients treated with pancreaticoduodenectomy were reviewed. Hepatic artery anomalies were classified by the Michels method.

RESULTS

15 patients treated with pancreaticoduodenectomy had hepatic artery anomalies (9 males, 6 females; mean age 58.3 years, range 25-72 years). Patients were given preoperative examination consisting of contrast-enhanced CT (n = 15) and celiomesenteric angiography (n = 10). Pylorus-preserving pancreaticoduodenectomy (PPPD) was performed in 7 patients, and radical pancreaticoduodenectomy in the other 8 cases. Hepatic artery anomalies were diagnosed as Michels type II (n = 3), with a replaced left hepatic artery arising from the left gastric artery; Michels type III (n = 6), with a replaced right hepatic artery branching off the superior mesenteric artery; Michels type V (n = 2), with a dual arterial supply with an accessory left hepatic artery that arose from the left gastric artery; Michels type VI (n = 3), with a dual arterial supply with an accessory right hepatic artery that arose from the superior mesenteric artery, and Michels type IX (n = 1), with the common hepatic artery originating from the superior mesenteric artery. The aberrant hepatic arteries were correctly identified on CT scan in 10 cases, with an accuracy of 67% (10/15). The anomalies were detected by DSA in all the 10 cases, and the accuracy was 100% (10/10). All the aberrant hepatic arteries except one were successfully preserved during the operation, with no surgical mortalities and postoperative complications in 6 patients (40%).

CONCLUSIONS

It is inferredthat hepatic artery anomalies are not rare in patients with ampullary tumors. Preoperative CT and angiography should play a critical part in the preoperative evaluation of hepatic artery anomalies whenever and wherever available. and IAP.

Comparison of high-resolution contrast-enhanced 3D MRA with digital subtraction angiography in the evaluation of hepatic arterial anatomy

AIM

To evaluate the validity of high-resolution contrast-enhanced three-dimensional magnetic resonance angiography (MRA) in defining hepatic arterial anatomy and to compare this with digital subtraction angiography (DSA).

MATERIALS AND METHODS

MRA and DSA were performed in 30 patients. MRA was performed with breath-hold, gadolinium-enhanced, three-dimensional, fast low-angle shot sequence with a 512 pixel matrix. MRA was compared with DSA in terms of image quality and depiction of hepatic arterial anatomy. The agreement in image quality between MRA and DSA was determined with the kappa statistic.

RESULTS

With respect to image quality, there was excellent or good correlation between MRA and DSA for the common hepatic artery (kappa=0.85), proper hepatic artery (kappa=0.72), gastroduodenal artery (kappa=0.70), left hepatic artery (kappa=0.49), left gastric artery (kappa=0.50), splenic artery (kappa=0.84), and superior mesenteric artery (kappa=0.88). Poor correlation was found for the right hepatic artery (kappa=0.18) and right gastric artery (kappa=0.38). With regard to hepatic arterial anatomy, MRA correlated correctly with DSA in 28 of the 29 cases, i.e. 97% of patients.

CONCLUSION

MRA is a useful technique for the evaluation of the hepatic artery, and for the vast majority of patients, MRA can replace intra-arterial DSA.

Using multidetector CT for preoperative vascular evaluation of liver neoplasms: technique and results

OBJECTIVE

The purpose of our study was to evaluate the performance of CT angiography using multidetector CT (MDCT) for preoperative vascular evaluation in candidates who were scheduled for liver neoplasm resection.

SUBJECTS AND METHODS

Forty-two consecutive subjects with malignant liver tumors scheduled for resection were studied with multiphase MDCT. The first 22 subjects underwent both multiphase MDCT angiography and catheter angiography before surgery. The subsequent 20 subjects underwent only preoperative CT angiography. Postprocessing was performed, and the images were analyzed for the depiction of arterial, portal vein, and hepatic vein anatomy and for the identification of important vascular variants. The postprocessing findings were compared and correlated with the findings from catheter angiography (22/42) or intraoperative sonography (42/42) and surgery (42/42).

RESULTS

Arterial anomalies were detected on the images of 17 of 42 patients, including a replaced right hepatic artery in five, replaced left hepatic artery in six, accessory right and left hepatic arteries in two, common trunk for the celiac and superior mesenteric arteries in one, and early bifurcation of the celiac artery in one. In 22 patients in whom catheter angiography confirmation was available, the number of arteries and almost all the significant anomalies were correctly identified on CT angiography (accuracy, 97%; sensitivity, 94%; specificity, 100%). In the subset of 20 patients who underwent MDCT angiography without catheter angiography confirmation, all clinically relevant information was provided by CT angiography. The portal and hepatic vein anatomy and the relationships of the liver tumors to the neighboring venous structures were shown on CT.

CONCLUSION

Multidetector CT provides valuable preoperative information about hepatic vascular architecture and can be used as a noninvasive alternative to catheter angiography before oncologic liver surgery.

Demonstration of aberrant hepatic and gastric arteries with helical CT

RATIONALE AND OBJECTIVES

To assess the demonstration of aberrant hepatic and gastric arteries with routine axial biphasic helical CT.

METHODS

The arterial-phase images of biphasic helical CT were reviewed to evaluate aberrant hepatic and gastric arteries in 166 patients with hepatocellular carcinomas. Biphasic (30 and 70 seconds) helical CT was performed with 10 mm of collimation. The results were compared with angiography performed within 2 weeks after this CT.

RESULTS

Aberrant hepatic arteries were identified by CT in 38 patients and by angiography in 43 patients (38/43, 88%). Aberrant left gastric arteries were identified in three patients by angiography and by CT (3/3). Careful observation of the fissure for the ligamentum venosum and portacaval space was useful for the detection of these arteries.

CONCLUSIONS

Aberrant hepatic and gastric arteries were well demonstrated with routine axial biphasic helical CT. This may be useful for the surgical and transcatheter management of hepatic tumors.

Hepatic blood supply: comparison of optimized dual phase contrast-enhanced three-dimensional MR angiography and digital subtraction angiography

PURPOSE

To optimize and determine the value of dual-phase contrast material-enhanced three-dimensional (3D) magnetic resonance (MR) angiography for preoperative evaluation of the blood supply to the liver.

MATERIALS AND METHODS

Dual phase 3D MR angiography of the hepatic arteries and portal vein was performed in 140 patients. In 80 patients, the value of fat saturation, digital image subtraction, an anticholinergic agent, and a high-caloric meal were evaluated. In the next 60 patients, MR angiographic and digital subtraction angiographic (DSA) image quality and diagnostic value were compared.

RESULTS

Fat-saturated images were of significantly better quality (P < .01) than non-fat-saturated images. Digital image subtraction was useful in only 23 of 40 patients. The injection of an anticholinergic agent was superfluous, whereas administration of a high-caloric meal helped in demonstration of the superior mesenteric artery and portal vein. Classification on MR angiograms of the arterial blood supply was correct in 57 of 60 patients. All arterial and portal venous lesions were seen on MR angiograms, and MR angiograms had a significantly higher subjective image-quality ranking than did DSA images in the evaluation of the portal vein (P < .05).

CONCLUSION

Fat saturation and use of a high-caloric meal improve the results of MR angiography of hepatic vessels. MR angiography was comparable to DSA for evaluation of the arterial system and was superior for demonstration of the portal vein; therefore, MR angiography could replace intraarterial DSA.

Dual-phase spiral CT angiography with volumetric 3D rendering for preoperative liver transplant evaluation: preliminary observations

PURPOSE

The goal of our study was to determine whether dual-phase spiral CT angiography with 3D volume rendering could be used for preoperative evaluation and patient selection for orthotopic liver transplantation candidates.

METHOD

Fifty consecutive potential candidates for liver transplantation were evaluated with dual-phase spiral CT with 3D volume rendering. Intravenous contrast medium was administered as bolus peripheral injection at 3 ml/s. The protocol consisted of a contrast-enhanced dual-phase spiral CT (arterial phase acquisition at 30 s after initiation of contrast medium injection followed by portal venous phase beginning at 60 s) with scan parameters of 0.75 s gantry rotation speed, 3 mm collimation, 5 to 6 mm/s table speed, and reconstruction at 1 mm intervals for arterial-phase images and 3 mm collimation for portal venous-phase studies (Siemens Plus 4 scanner; Siemens Medical Systems, Iselin, NJ, U.S.A.). All scan information was sent to a free-standing workstation (Silicon Graphics Onyx or Infinite Reality, Mountain View, CA, U.S.A.) for interactive real-time 3D volume rendering using a customized version of the Volren volume renderer (Silicon Graphics; Advanced Imaging Laboratory, Johns Hopkins Medical Institutions, Baltimore, MD, U.S.A.). The arterial phase was used to create vascular maps of the celiac axis including the origin(s) of the hepatic artery and origin of the superior mesenteric artery. The portal phase was used to define portal venous patency as well as the hepatic venous anatomy. All images were analyzed for vascular patency, shunting, or collateralization as well as the status of the underlying liver (i.e., liver size, cirrhosis, tumor, etc.).

RESULTS

All 50 studies were successfully completed without complication. The 3D CT angiograms defined key arterial and venous structures including origin(s) of the hepatic artery, portal vein and/or superior mesenteric vein thrombosis, cavernous transformation of the portal vein, and/or other collateral vasculature. Ten patients (20%) demonstrated anomalous anatomy at the origin(s) of the hepatic artery. Portal vein thrombosis with cavernous transformation of the portal vein was shown in six patients, and there were three cases of partial venous thrombosis. Underlying liver tumors as well as parenchymal liver disease were well defined. Hepatic masses were found in five patients. Masses were pathologically proven as hepatocellular carcinoma (n = 1), giant cavernous hemangioma (n = 1), hepatic adenoma (n = 1), and focal nodular hyperplasia (n = 2).

CONCLUSION

Preliminary results suggest that dual-phase spiral CT with CT angiography can provide a comprehensive preoperative liver transplant evaluation, supplying the necessary information for patient selection and surgical planning. As a single, minimally invasive examination, this should significantly impact patient care by minimizing procedures and avoiding potential complications.