Aberrant hepatic artery in patients undergoing pancreaticoduodenectomy

Impact of hepatic artery variation on surgical and oncological outcomes in robotic pancreaticoduodenectomy

BACKGROUND

In patients with hepatic artery variation (HAV), feasibility and justification of robotic pancreatoduodenectomy (RPD) for periampullary lesions have been not been well established.

METHODS

A total of 600 patients with periampullary lesions receiving RPD or open pancreaticoduodenectomy (OPD) were identified from our prospectively collected computer database. Surgical outcomes, oncological radicality, and survival outcomes after RPD in HAV ( +) and (-) patients were compared.

RESULTS

The incidence of HAV was 16%, including 12.7% in patients with RPD and 23.0% in those with OPD. In the HAV ( +) group, vascular injury rate had no statistical difference between the RPD (3.7%) and OPD (9.1%) patients, P = 0.404. Among the RPD patients, those with HAV ( +) had longer operation time (8.5 ± 2.5 vs. 7.7 ± 2.0 h, P = 0.013) and higher vascular injury (3.8% vs. 0.6%, P = 0.024) when compared with the HAV (-) patients. There was no significant difference between the HAV ( +) and (-) patients with RPD regarding blood loss, open conversion, vascular resection, and surgical mortality and morbidity. There was no survival difference between the HAV ( +) and (-) patients with pancreatic head adenocarcinoma after RPD. There was no survival difference between RPD and OPD in the HAV ( +) group.

CONCLUSIONS

When compared with OPD, RPD is feasible and justifiable without increasing vascular injury rate for patients with HAV ( +). Hepatic artery variation has no negative impact on surgical, oncological, and survival outcomes following an RPD, if it is accurately identified pre-operatively and appropriately managed intraoperatively.

Imaging of pancreatic ductal adenocarcinoma - An update for all stages of patient management

Background

Pancreatic ductal adenocarcinoma (PDAC) is a common and lethal cancer. From diagnosis to disease staging, response to neoadjuvant therapy assessment and patient surveillance after resection, imaging plays a central role, guiding the multidisciplinary team in decision-planning.

Review aims and findings

This review discusses the most up-to-date imaging recommendations, typical and atypical findings, and issues related to each step of patient management. Example cases for each relevant condition are presented, and a structured report for disease staging is suggested.

Conclusion

Despite current issues in PDAC imaging at different stages of patient management, the radiologist is essential in the multidisciplinary team, as the conveyor of relevant imaging findings crucial for patient care.

Influence of aberrant right hepatic artery on survival after pancreatic resection for ductal adenocarcinoma of the pancreatic head

PURPOSE

The presence of an aberrant right hepatic artery (aRHA), arising from the superior mesenteric artery, is a common variant of the liver vascular anatomy. Considering that tumor spread occurs along vessels, the question arises, whether the presence of an aRHA influences the oncologic outcome after resection for cancer of the pancreatic head.

METHODS

Patients with ductal adenocarcinoma of the pancreatic head, who underwent resection from 2011 to 2020 at the Frankfurt University Hospital, Germany, were analyzed retrospectively. Surgical records and computed tomography imaging were reviewed for the presence of aRHA. Overall and disease-free survival as well as hepatic recurrence were analyzed according to the presence of aRHA.

RESULTS

aRHA was detected in 21 out of 145 patients (14.5%). The median overall survival was 26 months (95%CI 20.8-34.4), median disease-free survival was 12.1 months (95%CI 8.1-17.3). There was no significant difference in overall survival (26.1 versus 21.4 months, adjusted hazard ratio 1.31, 95%CI 0.7-2.46, p = 0.401) or disease-free survival (14.5 months versus 12 months, adjusted hazard ratio 0.98, 95%CI 0.57-1.71, p = 0.957) without and with aRHA. The hepatic recurrence rate was 24.4.% with conventional anatomy versus 30.8% with aRHA (adjusted odds ratio 1.36, 95%CI 0.3-5.38, p = 0.669). In the multivariable analysis, only lymphatic vessel invasion was an independent prognostic factor for hepatic recurrence.

CONCLUSIONS

The presence of an aRHA does not seem to influence the long-term survival and hepatic recurrence after resection for ductal adenocarcinoma of the pancreatic head.

Hepatic Artery Anomalies in Pancreaticoduodenectomy: Outcomes from a High-Volume Center

INTRODUCTION

Hepatic artery anomalies (HAA) may have an impact on surgical and oncological outcomes of patients undergoing pancreaticoduodenectomy (PD).

METHODS

Patients who underwent PD at our institution between July 2015 and January 2020 were retrospectively reviewed and classified into two groups: group 1, with presence of HAA, and group 2, with no HAA. A weighted logistic regression model was employed to assess the association between HAA and postoperative complications, and to assess the association between HAA and R status in patients with pancreatic cancer.

RESULTS

502 patients were considered for analysis, with 75 (15%) of them in group 1. They had either an accessory (n = 28, 40.8%) or replaced (n = 26, 36.6%) right hepatic artery. Most patients underwent surgery for a malignancy (n = 451; 90%); among them, vascular resection was performed in 69 cases (15%). The presence of a HAA was reported at preoperative imaging only in 4 cases (5%) and the aberrant vessel was preserved in 72% of patients. At weighted multivariable logistic regression analysis, HAA were not associated to higher odds of morbidity (odds ratio [OR]: 0.753, 95% confidence interval [CI]: 0.543-1.043) nor to R1 status in case of pancreatic cancer (OR: 1.583, 95% CI: 0.979-2.561).

CONCLUSION

At our institution, the presence of HAA does not have an impact on postoperative outcomes or affects oncological clearance after PD. Hospitals', surgeons', volume and systematic review of preoperative imaging are all factors that help reduce possible adverse events.

Clinical significance of variant hepatic artery in pancreatic resection: A comprehensive review

The anatomical structure of the pancreaticoduodenal region is complex and closely related to the surrounding vessels. A variant of the hepatic artery, which is not a rare finding during pancreatic surgery, is prone to intraoperative injury. Inadvertent injury to the hepatic artery may affect liver perfusion, resulting in necrosis, liver abscess, and even liver failure. The preoperative identification of hepatic artery variations, detailed planning of the surgical approach, careful intraoperative dissection, and proper management of the damaged artery are important for preventing hepatic hypoperfusion. Nevertheless, despite the potential risks, planned artery resection has become acceptable in carefully selected patients. Arterial reconstruction is sometimes essential to prevent postoperative ischemic complications and can be performed using various methods. The complexity of procedures such as pancreatectomy with en bloc celiac axis resection may be mitigated by the presence of an aberrant right hepatic artery or a common hepatic artery originating from the superior mesenteric artery. Here, we comprehensively reviewed the anatomical basis of hepatic artery variation, its incidence, and its effect on the surgical and oncological outcomes after pancreatic resection. In addition, we provide recommendations for the prevention and management of hepatic artery injury and liver hypoperfusion. Overall, the hepatic artery variant may not worsen surgical and oncological outcomes if it is accurately identified pre-operatively and appropriately managed intraoperatively.

The Impact of Aberrant Hepatic Artery on Resection Margin and Outcomes of Laparoscopic Pancreatoduodenectomy: A Single-Center Report

BACKGROUND

Variations in the anatomy of the hepatic artery are common. This study was aimed at sharing our experience with identifying and protecting the aberrant hepatic artery (AHA) and discussing its impact on the resection margin and outcomes of laparoscopic pancreatoduodenectomy (LPD).

METHODS

A total of 576 patients who underwent LPD between 2015 and 2020 were retrospectively selected and divided into AHA and no AHA groups for this study. The demographics of the patients, pathological features, surgical data, and postoperative complications were further compared and analyzed between the two groups.

RESULTS

The AHA group included 127 patients (22.05%). No statistically significant differences were found between the AHA and no AHA groups in the intraoperative data, postoperative complications, and long-term survival with malignant tumor. There was also no significant difference in the R1 rate for pancreatic adenocarcinoma.

CONCLUSIONS

AHA appears frequently; however, it does not change the incidence of perioperative adverse events following LPD or the long-term prognosis of malignant tumor. The preservation of AHA during surgery can be achieved with a well-planned approach and careful dissection.

Impact of Vascular Anomalies on Pancreatoduodenectomy Procedure

Background

One of the critical steps during pancreatoduodenectomy (PD) procedure lies in identifying the complicated vascular anatomy of the resected area. The blood supply usually stems from branches of the celiac and the superior mesenteric arteries. However, only in 55-79% of surgeries, the anatomy of the blood vessels encountered by the surgeon is considered normal, while in the remaining cases, there are vascular variations that make these surgeries even more challenging. Any change or deviation from the known surgical course of PD makes surgery difficult and can result in an increase in intra/postoperative complications. In order to reduce difficulties encountered during PD, as well as reducing complication rates and improving surgical outcomes, a preliminary design, which includes preoperative identification of anatomical variations, is needed. The most accurate and accessible tool for identifying such variations is computed tomographic angiography (CTA). The aim of this retrospective study is to assess the prevalence of vascular anomalies encountered during PD, and examine whether there is an association between these anomalies and intra/postoperative morbidity and mortality.

Methods

A retrospective study over 5 years was performed at the HPB and Surgical Oncology Unit, Rambam Health Care Campus, Haifa, Israel. The charts of all patients submitted to PD were reviewed, and all patients with vascular anomalies were included. The types of anatomical variant as well as other information were collected. For statistical purposes, the group of patients with vascular anomalies was compared to a control group with identical demographic characteristics. A statistical analysis on possible association between vascular anomalies and intra/postoperative complications (mainly bleeding) was performed.

Results

During the aforementioned period, 202 patients underwent PD, and in 41 (20.3%) vascular anomalies were identified. The majority of these patients (32/41) had single anatomical variant, where two and three anatomical variants were identified in seven and two patients, respectively. The most common vascular anomaly was replaced right hepatic artery, noticed in 34 patients (83%). The most common indication for PD for both groups (anatomical variant and control group) was pancreas adenocarcinoma (56%). Intraoperative complication, in the form of bleeding, developed in 6/41 patients (14.6%) of the anatomical variant group and none in the control group. Postoperative complication rates, including post- pancreatoduodenectomy hemorrhage (PPH), postoperative pancreatic fistula (POPF), intra-abdominal abscess and wound infection were almost identical for both groups. One case of death within 30 days occurred, and it was in the anatomical variant group.

Conclusions

Anatomical vascular anomalies are a common variant encountered during PD, with RRHA being the most common. Although postoperative morbidity and mortality are not affected by the presence of these anomalies, intraoperative bleeding rate is higher in this specific group, thus; a preoperative diagnosis by means of CTA is mandatory.

Pancreatectomy with Hepatic Artery Resection for Pancreatic Head Cancer

BACKGROUND

To report our experiences and outcome of pancreatectomy with hepatic artery resection (PT-HAR) for advanced pancreatic head cancer.

METHODS

A retrospective study of clinical data from 14 patients with advanced pancreatic ductal adenocarcinoma undergoing PT-HAR in a tertiary academic center between March 2010 and June 2017 was performed. Furthermore, a comparison in a match-pair analysis (1:3) with patients received standard pancreatectomy during the same period was conducted to evaluate the clinical outcome.

RESULTS

The PT-HAR cohort included pancreaticoduodenectomy (n = 11) and total pancreatectomy (n = 3). Of them, six underwent portal/superior mesenteric vein resection and reconstruction and three underwent hepatic artery reconstruction. Four patients without arterial reconstruction developed liver perfusion failure. No perioperative mortality occurred, with a median postoperative hospital stay of 10.5 days (range 6-39). The median overall survival was 30 months (95% confidence interval 9.8-50.2 months), with the 1-, 2-, and 3-year survival rates of 81.8%, 63.6%, and 42.4%, respectively. The matched-pair data analysis showed no significant differences between PT-HAR and standard pancreatectomy, except that liver perfusion failure occurred more frequently after PT-HAR.

CONCLUSIONS

PT-HAR can be performed with acceptable morbidity, mortality, and survival for advanced pancreatic head cancer. Considering the potential risk of liver perfusion failure, only highly selected patients are eligible for PT-HAR without reconstruction.

Virtual reality with three-dimensional image guidance of individual patients' vessel anatomy in laparoscopic distal pancreatectomy

PURPOSE

Three-dimensional virtual endoscopy (3DVE) has the potential advantage of enhanced anatomic delineation and spatial orientation during laparoscopic procedures. In the present study, we aimed to evaluate the impact of 3DVE guidance in laparoscopic distal pancreatectomy (LDP).

METHODS

Thirty-eight patients presenting to our hospital with a variety of pancreatic tumors underwent preoperative computed tomography scanning to clearly define the major peripancreatic vasculature and correlate it with a 3DVE system (SYNAPSE VINCENT: Fujifilm Medical, Tokyo, Japan). This map served as the guide during preoperative planning, surgical education, and simulation and as intraoperative navigation reference for LDP. Operative records and pathological findings were analyzed for each procedure. Operative parameters were compared between the 38 patients in this study and 8 patients performed without 3DVE guidance at our institution.

RESULTS

The 3DVE navigation system successfully created a preoperative resection map in all patients. Relevant peripancreatic vasculature displayed on the system was identified and compared during the intervention. The mean blood loss in LDP performed under 3DVE guidance versus LDP without 3DVE was 168.5 +/- 347.6 g versus 330.0 +/- 211.4 g, p = 0.008 while and the operative time was 171.9 +/- 51.7 min versus 240.6 +/- 24.8 min, p = 0.001.

CONCLUSIONS

3DVE in conjunction with a "laparoscopic eye" creates a preoperative and intraoperative three-dimensional data platform that potentially enhances the accuracy and safety of LDP.

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.

Aberrant left hepatic arteries arising from left gastric arteries and their clinical importance

BACKGROUND

The Aberrant Left Hepatic Artery (ALHA) is replaced when it does not originate from the hepatic artery proper and it is the only supply to that part of the liver, while an accessory artery coexists with a normal artery. The aim of this systematic review is to evaluate the incidence of ALHAs including the one arising from the Left Gastric Artery, also named Hyrtl's artery.

METHODS

A literature search in PubMed, SCOPUS, WOS and Google Scholar was performed. The risk of bias was assessed by means of the AQUA tool. The main outcome was the prevalence of ALHA. Secondary outcomes were the prevalence of the accessory and replaced left hepatic arteries. A subgroup analysis was conducted by geographic region and type of evaluation.

RESULTS

This review included 57 studies, with a total of 19,284 patients. The majority of the studies involved the use of radiological techniques -especially Angio-CT-and were performed in Asia. The overall risk of bias was moderate. The overall prevalence of the ALHA was 13.52%; the overall prevalence was 8.26% for the Replaced ALHA and 5.55% for the Accessory ALHA. In the 18 studies that employed Michels' classification, Type II had the lowest prevalence (0.36%) and Type VII the highest prevalence (6.62%).

DISCUSSION

Some of the studies included did not distinguish between the ''replaced'' and ''accessory'' ALHA (34.25%). Some surgical dissection techniques proved insufficient for the localization of other hepatic arteries. These results suggest that an accurate preoperative radiological evaluation is needed to localize replaced arteries.

Robotic pancreaticoduodenectomy in the presence of aberrant or anomalous hepatic arterial anatomy: safety and oncologic outcomes

BACKGROUND

Hepatic arterial anomalies (HAAs) are not infrequently encountered during pancreatic resections. In view of the current emergence of the robotic platform as a safe alternative to open surgery in experienced centres, this study sought to determine the implications of HAAs on the safety and oncologic outcomes of robotic pancreaticoduodenectomy (RPD).

METHODS

A prospectively maintained database of patients with HAAs who underwent RPD (RPD + HAA) at a single institution between 2008 and 2013 was retrospectively reviewed. Demographic information and perioperative outcomes of RPD were compared for patients with and without HAAs.

RESULTS

A total of 142 patients underwent RPD; 112 (78.9%) did not have and 30 (21.1%) did have HAAs. The majority (90.0%) of RPDs in patients with HAAs were performed for malignant indications and all aberrant vessels were preserved without conversion to laparotomy. There were no statistically significant differences between RPD patients with and without HAAs with respect to preoperative demographics, tumour characteristics, operative metrics (operative time, estimated blood loss, conversion) and postoperative outcomes, including complications, length of stay and readmissions. Negative margin (R0) rates were similar in both groups.

CONCLUSIONS

Robot-assisted pancreaticoduodenectomy is safe and feasible in patients with HAAs and has outcomes similar to those in patients with normal arterial anatomy.

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.

Hind right approach pancreaticoduodenectomy: from skill to indications

Background. Pancreaticoduodenectomy is the potentially curative treatment for malignant and several benign conditions of the pancreatic head and periampullary region. While performing pancreaticoduodenectomy, early neck division may be impossible or inadequate in case of hepatic artery anatomic variants, suspected involvement of the superior mesenteric vessels, intraductal papillary mucinous neoplasm, and pancreatic head bleeding pseudoaneurysm. Our work aims to highlight a particular hind right approach pancreaticoduodenectomy in selected indications and assess the preliminary results. Methods. We describe our early hind right approach to the retropancreatic vasculature during pancreaticoduodenectomy by mesopancreas dissection before any pancreatic or digestive transection. Results. We used this approach in 52 patients. Thirty-two had hepatic artery anatomic variant and 2 had bleeding pancreatic head pseudoaneurysm. The hepatic artery variant was preserved in all cases out of 2 in which arterial reconstruction was performed. In nine patients with intraductal papillary mucinous neoplasms the pancreaticoduodenectomy was extended to the body in 6 and totalized in 3 patients. Seven patients with adenocarcinoma involving the portomesenteric axis required venous resection and reconstruction. Conclusions. Early hind right approach is advocated in selected cases of pancreaticoduodenectomy to improve locoregional vascular control and determine, safely and early, whether there is mesopancreas involvement.

Implications of the presence of an aberrant right hepatic artery in patients undergoing pancreaticoduodenectomy

AIM: To analyze the differences in outcomes and the clinical impact following pancreatoduodenectomy (PD) in patients with and without aberrant right hepatic artery (aRHA).

METHODS: All patients undergoing PD between January 2008 and December 2012 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 and the postoperative morbidity, mortality and hospital stay.

RESULTS: A total of 225 patients underwent PD, of which 43 (19.1%) patients were found to have either accessory or replaced right hepatic arteries (aRHA group). The aRHA was preserved in 79% of the patients. There was no significant difference in the intraoperative blood loss but operative time was prolonged, reflecting the complexity of the procedure [420 ± 44 (240-540) min vs 480 ± 45 (300-600) min, P < 0.05)]. There were no differences in the incidence of postoperative complications (pancreatic leak, pancreatic fistula, delayed gastric emptying and mortality) and hospital stay. Oncological clearance in the form of positive resection margins [13 (7.1%) vs 3 (6.9%)] and lymph node yield were also similar in the two groups.

CONCLUSION: An aRHA is found in approximately one fifth of patients undergoing PD. Preservation is technically possible in most patients and can increase the operative complexity but does not negatively affect the safety or oncological outcomes of the procedure.

Retroportal lamina or mesopancreas? Lessons learned by anatomical and histological study of thirty three cadaveric dissections

OBJECTIVE AND BACKGROUND

Despite its importance in pancreatic head carcinoma, the retroportal lamina is still under studied, with only two anatomical cadaveric dissections in the English literature, with recent controversies about the concept of a mesopancreas.

METHODS

Resection of the mesopancreas was performed in 33 fresh cadavers. The pancreas and mesopancreas were separated from each other and the mesopancreas was immunohistochemically investigated.

RESULTS

The retroportal lamina is roughly rectangular in shape. Its dimensions are: height 6.2 cm (5-8), 2.5 cm wide (1.5-4). It contains a right hepatic artery arising from the superior mesenteric artery in 13.3% of cases. Microscopic examination revealed areolar tissue, adipose tissue, peripheral nerve, nerve plexus, lymphatics and capillaries. However, fibrous sheath and fascia were not found around these structures.

CONCLUSION

A right hepatic artery arising from the superior mesenteric artery is a frequent anatomic variation. Surgeons must be aware of this to ensure the integrity of the hepatic artery blood supply in patients treated by pancreaticoduodenectomy. Despite controversy about the reality of the mesopancreas (postulated in analogy to the mesorectum), because of the absence of fibrous sheath or fascia, its complete removal in pancreatic head carcinoma is feasible by a subadventitial dissection of the superior mesenteric artery which can be considered as the real limit of the mesopancreas.

Technical tailoring of pancreaticoduodenectomy in patients with hepatic artery anatomic variants

BACKGROUND

Pancreaticoduodenectomy is the treatment of choice for periampullary and pancreatic head tumors. In case of hepatic artery abnormalities, early pancreatic transection during pancreaticoduodenectomy may prove inappropriate. Early retroportal lamina dissection improves exposure of the superior mesenteric vessels and anatomic variants of the hepatic artery, where safeguarding is mandatory.

METHOD

We describe our early retroportal lamina approach in patients with anatomic variants of the hepatic artery before pancreatic transection.

RESULTS

This approach was used during 42 pancreaticoduodenectomies with a hepatic artery anatomic variant which was spared in 40 patients. Arterial reconstruction was performed in 2 patients. Five patients with a hepatic artery variant and adenocarcinoma involving the portomesenteric junction required venous resection and reconstruction.

CONCLUSIONS

Early retroportal lamina dissection during pancreaticoduodenectomy in patients with hepatic artery anatomic variants enables easier exposure, avoiding injuries that might compromise the liver arterial supply. When the portomesenteric vein is involved, this approach facilitates en bloc "no touch" venous resection and reconstruction.

Overcoming drug resistance in pancreatic cancer

INTRODUCTION

Pancreatic cancer has the worst survival rate of all cancers. The current standard care for metastatic pancreatic cancer is gemcitabine, however, the success of this treatment is poor and overall survival has not improved for decades. Drug resistance (both intrinsic and acquired) is thought to be a major reason for the limited benefit of most pancreatic cancer therapies.

AREAS COVERED

Previous studies have indicated various mechanisms of drug resistance in pancreatic cancer, including changes in individual genes or signaling pathways, the influence of the tumor microenvironment, and the presence of highly resistant stem cells. This review summarizes recent advances in the mechanisms of drug resistance in pancreatic cancer and potential strategies to overcome this.

EXPERT OPINION

Increasing drug delivery efficiency and decreasing drug resistance is the current aim in pancreatic cancer treatment, and will also benefit the treatment of other cancers. Understanding the molecular and cellular basis of drug resistance in pancreatic cancer will lead to the development of novel therapeutic strategies with the potential to sensitize pancreatic cancer to chemotherapy, and to increase the efficacy of current treatments in a wide variety of human cancers.

Article Commentary: Aberrant Hepatic Arterial Anatomy and the Whipple Procedure: Lessons Learned

Appreciation and study of hepatic arterial anatomical variability is essential to the performance of a pancreaticoduodenectomy to avoid surgical complications such as bleeding, hepatic ischemia/failure, and anastomotic leak/stricture. Awareness of this variability permits the surgeon to adapt the surgical technique to deal with anomalies identified preoperatively or intraoperatively thereby preventing unnecessary surgical morbidity and mortality. The objective of our study is to provide a comprehensive review of the anatomic arterial anomalies and discuss surgical strategies that will equip the surgeon to deal with all anomalies that may be encountered a priori or en passant during the course of a Whipple procedure.

Liposome based delivery systems in pancreatic cancer treatment: from bench to bedside

Despite rapid advances in cancer diagnosis and treatment, pancreatic cancer remains one of the most difficult human malignancies to be treated, with a mortality rate nearly equal to its incidence. Although gemcitabine has been established as the standard first-line treatment for advanced pancreatic cancer, gemcitabine-based combination chemotherapy showed either marginal or no improvement in survival. Developments in liposomal delivery systems have facilitated the targeting of specific agents for cancer treatment. Such systems could be developed as platforms for future multi-functional theranostic nanodevices tailor-made for the combined detection of early cancer and functional drug delivery. We systemically review liposome based drug-delivery systems, which can provide improved pharmacokinetics, reduced side effects and potentially increased tumor uptake, for pancreatic cancer therapy. Novel liposomal formulations allowing for higher tumor targeting efficiencies and used in current clinical trials to treat this challenging disease are emphasized.

Clinical implications of an aberrant right hepatic artery in patients undergoing pancreaticoduodenectomy

BACKGROUND

Sometimes, it seems to be difficult to preserve the aberrant hepatic artery (HA) during pancreaticoduodenectomy (PD), with respect to en bloc lymph node dissection, especially in the case of aberrant right hepatic artery (RHA). Therefore, we evaluated the influence of incomplete en bloc lymph node (LN) dissection when aberrant RHA arises.

METHODS

We reviewed 103 patients with mid-to-distal common bile duct (CBD) cancers who underwent PD by one surgeon at Asan Medical Center from December 1994 to November 2005 (73 men, 30 women; mean age, 61.1 +/- 9.4 (range: 40-84) years). The mean follow-up period was 32.7 months. We compared the normal RHA group with the aberrant RHA group.

RESULTS

Eighty-eight cases showed normal RHA anatomy, including nine cases (8.7%) of aberrant left hepatic artery (LHA) with normal RHA cases (normal HA group). RHA anomalies were observed in 15 cases (14.6%, aberrant HA group). In all cases, there was no direct invasion of cancer to aberrant HA. Among two groups, 43 cases (41.7%) showed recurrence and there was no significant difference in recurrence between two groups (p = 0.202). Three-year and 5-year overall survivals were 33.3% and 28.5% in the normal HA group, whereas 47.1% and 28.3% in the aberrant RHA group, respectively. There also was no statistically significant difference in survival (p = 0.763).

CONCLUSIONS

When performing PD for CBD cancer, aberrant RHA should be preserved if there was no cancerous invasion and it does not seem to affect the recurrence of disease and overall survival of patients.

Solid pseudopapillary tumor of the pancreas: a case series of 26 consecutive patients

OBJECTIVE

Solid pseudopapillary tumor (SPT) of the pancreas, which predominantly affects young women, is a relatively indolent entity with favorable prognosis. The aim of this study is to describe the clinicopathologic features and surgical management of this disease in our institution.

METHODS

A retrospective study of clinical data from 26 consecutive patients with SPT managed in a tertiary academic center between January 2002 and December 2007 was performed. Clinicopathologic factors were compared between benign and malignant cases to determine what features of the tumor could suggest malignant potential.

RESULTS

The 26 cases included 22 female and 4 male patients, and the average age was 32.3 years (range 15 to 64). Clinical symptoms were nonspecific and included upper abdominal pain or discomfort, abdominal distention, and back pain. The neoplasm was localized in the pancreatic head/neck in 14 patients and in the body/tail in 12 patients. The median diameter of these lesions was 6.25 cm (range 2 to 15). All of the tumors-including 8 pancreaticoduodenectomies, 10 distal pancreatectomies, 6 local resections, 1 total pancreatectomy, and 1 central pancreatectomy-were resected successfully. No patient received chemotherapy or radiotherapy after surgery. All of the patients except 1 were alive at a median follow-up of 32.5 months (range 3 to 69). One of the 2 patients with malignant SPT, in whom Ki-67 immunoreactivity was >25%, developed local recurrence with liver metastasis 4 months and died 6 months after surgery. There were no significant associations between clinicopathologic factors and malignancy.

CONCLUSIONS

SPT is a rare neoplasm with low malignant potential. Characteristic computed axial tomography and magnetic resonance imaging scans combined with age and sex profile should be sufficient for the decision to operate. Patients with malignant SPT should have careful follow-up. The high proliferative index assessed by immunohistochemical staining for Ki-67 may predict poor outcome of malignant SPT.