Feasibility of Surveillance for Mucinous Cystic Neoplasm of the Pancreas: A Multi-Institutional Retrospective Study of 328 Patients by the Japanese Pancreatic Society

OBJECTIVE

We aimed to elucidate the feasibility of surveillance of patients with mucinous cystic neoplasm (MCN).

METHODS

We performed a retrospective, multi-institutional study of 328 patients who underwent surgery for MCN at 18 Japanese institutions. Patients with MCN were divided into an immediate surgery group and a surveillance group, which underwent surgery after surveillance.

RESULTS

The median surveillance period until surgery in the surveillance group was 27 months (range, 7-165 months). Compared with the immediate surgery group, the surveillance group showed smaller tumor diameter (46 vs 50 mm, P = 0.01), more frequent laparoscopic approach (58% vs 37%, P < 0.01), and less frequent malignancy (7% vs 15%, P = 0.03). The new appearance of mural nodules and elevation of serum tumor markers were associated with malignancy in the surveillance group. Two patients in the surveillance group experienced postoperative recurrence, although there was no significant difference in recurrence or disease-free survival between the two groups. In the surveillance group, the 1-, 5-, and 10-year cumulative incidence rates of malignant MCN were 0.8%, 5.6%, and 36.5%, respectively.

CONCLUSION

As the risk of progression to malignant MCNs increases over the long term, MCNs should be resected rather than subjected to unnecessary surveillance.

Considerations in laparoscopic resection of giant pancreatic cystic neoplasms

Background:

Laparoscopic distal pancreatectomy (LDP) with (LDPS) or without splenectomy for cystic tumours in the body and tail has become the standard of care. Data on patients with large tumours of the body and tail of the pancreas are sparse.

Patients and Methods:

A retrospective analysis of a prospectively maintained database of patients who were managed with laparoscopic surgery for pancreatic cystic neoplasm since 2010 was done. Patients with cysts more than 8 cm were analysed. Clinical presentation, imaging, details of the surgical procedure and the outcomes were looked into.

Results:

Five patients of giant pancreatic cystic neoplasm (GPCN) were managed with LDPS. Four patients were female, mean age was 45 years (range 15–69 years). The mean cyst size was 11.2 cms (range 8–15 cm). The splenic vein was either stretched or thrombosed in all patients. Three patients had sinistral portal hypertension. All patients were operated with a modified five-port placement. None of the patients required conversion. Mean operative duration was 3½ h, blood loss was 80 ml approximately and none required a blood transfusion. One patient had a biochemical leak. All patients were discharged from the hospital by 3^rd postoperative day. Drain removal was done before discharge except in the patient with biochemical leak (removed on day 6). On a median follow-up of 89 months (range 1–120 months), two patients developed diabetes. There has been no Overwhelming post-splenectomy infections (OPSI).

Conclusion:

Laparoscopic distal pancreatectomy is feasible in patients with GPCN and offers the all the short-term benefits, namely lesser pain, no wound infections, early return of bowel activity, early return to orals and early discharge and early return to work. Splenectomy was required in all patients because of splenic vein thrombosis and portal hypertension in three and for technical reasons in the rest.

Precision vascular anatomy for minimally invasive distal pancreatectomy: A systematic review

BACKGROUND

Minimally invasive distal pancreatectomy (MIDP) is increasingly performed worldwide; however, the surgical anatomy required to safely perform MIDP has not yet been fully considered. This review evaluated the literature concerning peripancreatic vascular anatomy, which is considered important to conduct safe MIDP.

METHODS

A database search of PubMed and Ichushi (Japanese) was conducted. Qualified studies investigating the anatomical variations of peripancreatic vessels related to MIDP were evaluated using SIGN methodology.

RESULTS

Of 701 articles yielded by our search strategy, 76 articles were assessed in this systematic review. The important vascular anatomy required to recognize MIDP included the pancreatic parenchymal coverage on the root and the running course of the splenic artery, branching patterns of the splenic artery, confluence positions of the left gastric vein and the inferior mesenteric vein, forms of pancreatic veins including the centro-inferior pancreatic vein, characteristics of the left renal vein, and collateral routes perfusing the spleen following Warshaw's technique. Very few articles evaluating the relationship between the anatomical variations and surgical outcomes of MIDP were found.

CONCLUSIONS

The precise knowledge of peripancreatic vessels is important to adequately complete MIDP. More detailed anatomic analyses and descriptions will benefit surgeons and their patients who are facing these operations.

Prediction of the Probability of Malignancy in Mucinous Cystic Neoplasm of the Pancreas With Ovarian-Type Stroma: A Nationwide Multicenter Study in Japan

OBJECTIVE

The aim of the study was to develop a formula for predicting the probability of malignancy of mucinous cystic neoplasm (MCN) of the pancreas with ovarian-type stroma.

METHODS

A total of 364 patients were enrolled. A total score was calculated as the sum of the approximate integers of the odds ratios of the predictive factors identified by multivariate analysis. The relationship between the total score and pathological results was assessed.

RESULTS

A total of 321 patients had benign MCN and 43 had malignant MCN. Five possible predictive factors were analyzed: 56 years or older, high serum carcinoembryonic antigen level, high carbohydrate antigen 19-9 level, tumor size of 51 mm or greater, and the presence of mural nodules. The total score was significantly higher in patients with malignant MCN (median, 24; range, 0-37) compared with benign MCN (median, 5; range, 0-33; P < 0.001). Receiver operating characteristic curve analysis demonstrated that the area under the curve was 0.86, and the sensitivity and specificity of the total score for discriminating malignant MCNs were 72% and 83%, respectively, using a cut-off value of 22.

CONCLUSIONS

The current simple formula can predict the malignancy of MCN and may thus contribute to the adequate management of patients with MCN.

A multicenter prospective registration study on laparoscopic pancreatectomy in Japan: report on the assessment of 1,429 patients

BACKGROUND

Prospective studies are needed to understand the safety and feasibility of laparoscopic pancreatectomy. The aim of the present study was to describe laparoscopic pancreatectomy currently undertaken in Japan, using a prospective registration system.

METHODS

Patient characteristics and planned operations were registered preoperatively, and then the performed operation and outcomes were reported using an online system. Collected data were also compared between institutions based on their level of experience. This study was registered with UMIN000022836.

RESULTS

Available data were obtained from 1,429 patients at 100 Japanese institutions, including 1,197 laparoscopic distal pancreatectomies (LDPs) and 232 laparoscopic pancreatoduodenectomies (LPDs). The rates of completion for planned operations were 92% for LDP and 91% for LPD. Postoperative complication rates after LDP and LPD were 17% and 30%, and 90-day mortality rates were 0.3% and 0.4%, respectively. Shorter operation time, less blood loss, and lower incidence of pancreatic fistula were observed in institutions experienced in LDP. A higher rate of pure laparoscopic procedure and shorter operation time were noted in institutions experienced with LPD.

CONCLUSION

LDPs and LPDs are performed safely in Japan, especially in experienced institutions. Our data could support the next challenges in the field of laparoscopic pancreatectomy.

Difficulty scoring system in laparoscopic distal pancreatectomy

BACKGROUND

Several factors affect the level of difficulty of laparoscopic distal pancreatectomy (LDP). The purpose of this study was to develop a difficulty scoring (DS) system to quantify the degree of difficulty in LDP.

METHODS

We collected clinical data for 80 patients who underwent LDP. A 10-level difficulty index was developed and subcategorized into a three-level difficulty index; 1-3 as low, 4-6 as intermediate, and 7-10 as high index. The automatic linear modeling (LINEAR) statistical tool was used to identify factors that significantly increase level of difficulty in LDP.

RESULTS

The operator's 10-level DS concordance between the 10-level DS by the reviewers, LINEAR index DS, and clinical index DS systems were analyzed, and the weighted Cohen's kappa statistic were at 0.869, 0.729, and 0.648, respectively, showing good to excellent inter-rater agreement. We identified five factors significantly affecting level of difficulty in LDP; type of operation, resection line, proximity of tumor to major vessel, tumor extension to peripancreatic tissue, and left-sided portal hypertension/splenomegaly.

CONCLUSIONS

This novel DS for LDP adequately quantified the degree of difficulty, and can be useful for selecting patients for LDP, in conjunction with fitness for surgery and prognosis.

Feasibility of Prophylactic Pancreatojejunostomy in Possible High-Risk Patients for Prevention of Pancreatic Fistula during Enucleation or Limited Pancreatic Resection

The aim of this study was to assess the feasibility of prophylactic pancreatojejunostomy after enucleation or limited pancreatic resection regarding the risk of postoperative pancreatic fistula (PF). We retrospectively reviewed the medical records of 32 patients who underwent enucleation or limited pancreatic resection and compared the clinical parameters between patients with ( n = 10) and without ( n = 22) prophylactic pancreatojejunostomy. Prophylactic pancreatojejunostomy was performed in patients with a possible high risk ofPF. No operation-related mortality occurred. Operation time was significantly longer ( P < 0.01) and blood loss significantly greater ( P < 0.01) in patients with pancreatojejunostomy. Overall complications were more frequent ( P = 0.02) and postoperative hospital stay was significantly longer ( P = 0.02) in patients with pancreatojejunostomy. However, other assessed factors including the prevalence of postoperative PF did not differ between groups. In conclusion, prophylactic pancreatojejunostomy is feasible, and its efficacy in preventing PF after enucleation or limited pancreatic resection in high-risk patients will require further study.

The Hand-Assisted Laparoscopic Approach to Resection of Pancreatic Mucinous Cystic Neoplasms: An Underused Technique?

Pancreatic mucinous cystic neoplasms (MCNs) are rare tumors typically of the distal pancreas that harbor malignant potential. Although resection is recommended, data are limited on optimal operative approaches to distal pancreatectomy for MCN. MCN resections (2000–2014; eight institutions) were included. Outcomes of minimally invasive and open MCN resections were compared. A total of 289 patients underwent distal pancreatectomy for MCN: 136(47%) minimally invasive and 153(53%) open. Minimally invasive procedures were associated with smaller MCN size (3.9 vs 6.8 cm; P = 0.001), lower operative blood loss (192 vs 392 mL; P = 0.001), and shorter hospital stay(5 vs 7 days; P = 0.001) compared with open. Despite higher American Society of Anesthesiologists class, hand-assisted (n = 46) had similar advantages as laparoscopic/robotic (n = 76). When comparing hand-assisted to open, although MCN size was slightly smaller (4.1 vs 6.8 cm; P = 0.001), specimen length, operative time, and nodal yield were identical. Similar to laparoscopic/robotic, hand-assisted had lower operative blood loss (161 vs 392 mL; P = 0.001) and shorter hospital stay (5 vs 7 days; P = 0.03) compared with open, without increased complications. Hand-assisted laparoscopic technique is a useful approach for MCN resection because specimen length, lymph node yield, operative time, and complication profiles are similar to open procedures, but it still offers the advantages of a minimally invasive approach. Hand-assisted laparoscopy should be considered as an alternative to open technique or as a successive step before converting from total laparoscopic to open distal pancreatectomy for MCN.

[Minimally invasive and robot-assisted surgery for pancreatic cystic tumors]

BACKGROUND

The indications for resection of pancreatic cystic lesions (PCL) are often complex and the operative risk has to be balanced against the risk of malignant transformation. The aim of the study was to provide a synopsis of the current treatment results of minimally invasive surgery for PCL.

METHODS

A systematic literature search was performed using the Medline database (PubMed). Subsequently, the retrieved literature was selectively reviewed.

RESULTS

No published prospective randomized controlled trials have yet addressed the comparison of open and minimally invasive surgery of PCL; however, retrospective case studies have demonstrated the feasibility, safety and a comparable morbidity after minimally invasive distal pancreatectomy (DP), pancreatoduodenectomy (PD), central (CP) or total pancreatectomy and enucleation. Whereas most DPs are performed laparoscopically, the experience of minimally invasive PD has been consolidated for the robot-assisted approach but is concentrated in only a few centers. The number of published reports on minimally invasive organ-sparing pancreas procedures (e. g. CP or enucleation) for PCL is scarce; however, the available (selected) results are promising.

CONCLUSION

Minimally invasive surgery for PCL has the potential to reduce the operative trauma to the patients, while at the same time causing comparable or less morbidity. This requires an increasing specialization of complex minimally invasive resections. The clinical use of robotic systems will grow for the latter cases. A prospective registry of the results should be mandatory for quality management.

Successful laparoscopic distal pancreatectomy for a large solid pseudopapillary neoplasm: A case report

A 30-year-old Japanese woman presented at our hospital with a pancreatic tumor. Contrast-enhanced CT revealed a tumor with a 12-cm diameter in the pancreatic body and tail. In the preoperative setting, endoscopic ultrasound-guided fine-needle aspiration permitted a histopathological diagnosis of solid pseudopapillary neoplasm. Twhe patient underwent laparoscopic distal pancreatectomy with splenectomy. Our procedure involved three steps. Firstly, the splenic artery was occluded to block inflow of blood to the tumor. Then, we transected the neck of the pancreas using radical antegrade modular pancreatosplenectomy. Finally, hand-assisted laparoscopic surgery allowed us to secure the operating field and easily handle the large tumor. This enabled us to accomplish laparoscopic distal pancreatectomy, and en-bloc resection was completed. The patient was discharged without major complications. Laparoscopic distal pancreatectomy for huge solid pancreatic tumors can be completed safely.

Laparoscopic surgery for pancreatic neoplasms: the European association for endoscopic surgery clinical consensus conference

BACKGROUND

Introduced more than 20 years ago, laparoscopic pancreatic surgery (LAPS) has not reached a uniform acceptance among HPB surgeons. As a result, there is no consensus regarding its use in patients with pancreatic neoplasms. This study, organized by the European Association for Endoscopic Surgery (EAES), aimed to develop consensus statements and clinical recommendations on the application of LAPS in these patients.

METHODS

An international panel of experts was selected based on their clinical and scientific expertise in laparoscopic and open pancreatic surgery. Each panelist performed a critical appraisal of the literature and prepared evidence-based statements assessed by other panelists during Delphi process. The statements were further discussed during a one-day face-to-face meeting followed by the second round of Delphi. Modified statements were presented at the plenary session of the 24th International Congress of the EAES in Amsterdam and in a web-based survey.

RESULTS

LAPS included laparoscopic distal pancreatectomy (LDP), pancreatoduodenectomy (LPD), enucleation, central pancreatectomy, and ultrasound. In general, LAPS was found to be safe, especially in experienced hands, and also advantageous over an open approach in terms of intraoperative blood loss, postoperative recovery, and quality of life. Eighty-five percent or higher proportion of responders agreed with the majority (69.5%) of statements. However, the evidence is predominantly based on retrospective case-control studies and systematic reviews of these studies, clearly affected by selection bias. Furthermore, no randomized controlled trials (RCTs) have been published to date, although four RCTs are currently underway in Europe.

CONCLUSIONS

LAPS is currently in its development and exploration stages, as defined by the international IDEAL framework for surgical innovation. LDP is feasible and safe, performed in many centers, while LPD is limited to few centers. RCTs and registry studies are essential to proceed with the assessment of LAPS.

Nature and management of pancreatic mucinous cystic neoplasm (MCN): A systematic review of the literature

BACKGROUND

The current management of pancreatic mucinous cystic neoplasms (MCN) is defined by the consensus European, International Association of Pancreatology and American College of Gastroenterology guidelines. However, the criterion for surgical resection remains uncertain and differs between these guidelines. Therefore through this systematic review of the existing literature we aimed to better define the natural history and prognosis of these lesions, in order to clarify recommendations for future management.

METHODS

A systematic literature search was performed (PubMed, EMBASE, Cochrane Library) for studies published in the English language between 1970 and 2015.

RESULTS

MCNs occur almost exclusively in women (female:male 20:1) and are mainly located in the pancreatic body or tail (93-95%). They are usually found incidentally at the age of 40-60 years. Cross-sectional imaging and endoscopic ultrasound are the most frequently used diagnostic tools, but often it is impossible to differentiate MCNs from branch duct intraductal papillary mucinous neoplasms (BD-IPMN) or oligocystic serous adenomas pre-operatively. In resected MCNs, 0-34% are malignant, but in those less than 4 cm only 0.03% were associated with invasive adenocarcinoma. No surgically resected benign MCNs were associated with a synchronous lesion or recurrence; therefore further follow-up is not required after resection. Five-year survival after surgical resection of a malignant MCN is approximately 60%.

CONCLUSIONS

Compared to other pancreatic tumors, MCNs have a low aggressive behavior, with exceptionally low rates of malignant transformation when less than 4 cm in size, are asymptomatic and lack worrisome features on pre-operative imaging. This differs significantly from the natural history of small BD-IPMNs, supporting the need to differentiate mucinous cyst subtypes pre-operatively, where possible. The findings support the recommendations from the recent European Consensus Guidelines, for the more conservative management of MCNs.

Laparoscopic distal pancreatectomy without needle aspiration before resection for giant mucinous cell neoplasms

Laparoscopic resection of large mucinous cystic neoplasms (MCN) has recently been reported. However, in most reports, needle aspiration of the cyst contents was performed before resection and can cause dissemination. Here, we report two patients with giant MCN: a 26-year-old woman with a 23-cm MCN and a 41-year-old woman with an 18-cm MCN. The MCN were successfully resected without aspiration by laparoscopic surgery. CT revealed no tumor involvement of the origins of the splenic artery and vein in either case. In case 1, we performed hand-assisted laparoscopic surgery while dissecting around the spleen, whereas case 2 underwent pure laparoscopic surgery. No postoperative complications occurred in either case, indicating that laparoscopic distal pancreatectomy for giant MCN is feasible without aspiration in patients without splenic artery and vein origin involvement.