Evolution of pancreatic surgery over time and effects of centralization-a single-center retrospective cohort study

Background

Short-term outcomes of pancreatic surgery have improved globally during the last two decades. Long-term survival of resectable pancreatic ductal adenocarcinoma (PDAC) has also shown slight improvement. We describe a cohort of 566 consecutive pancreatectomies performed at a Northern Finnish tertiary center. We analyze the trends in short-term outcomes of all-cause pancreatic surgery and long-term survival of PDAC patients.

Methods

All pancreatic resections performed at the Oulu University Hospital during years 2000-2020 were included. Patient data was analyzed in four time periods (2000-2005, 2006-2010, 2011-2015 and 2016-2020). Clinicopathological parameters of patients and tumors, complication data and short-term mortality were recorded for all patients and compared between time quartiles. Long-term survival and administration rates of neo-, and/or adjuvant therapy of PDAC patients were analyzed.

Results

A total of 566 pancreatectomies were performed during the study period: 359 (63%) pancreatoduodenectomies (PDs), 130 (23.0%) open left pancreatectomies (LPs), 45 (8.0%) laparoscopic LPs, 26 (5.1%) total pancreatectomies (TPs), and 6 (1.1%) enucleations. Median age of patients was 63 [57-71] years, and 49% [267] of patients were men. Number of pancreatectomies per time period increased from 67 in 2000-2005 to 266 in 2016-2020. American Society of Anesthesiologists (ASA) Physical Classification III patients and T3 tumors were more frequently operated on in later time periods. Complication rates remained at constant low levels throughout the study period, but reoperation rate increased from 9.4% in 2000-2010 to 16.2% in 2011-2020. Short-term (90-day) mortality after pancreatectomy decreased from 3.1% to 0.74%, while 5-year survival improved from 14.3% in 2006-2011 to 21.4% in 2011-2015. Resection rate of diagnosed PDAC cases, as reported by the Finnish Cancer Registry (FCR) for the catchment area, increased from 3.2% to 14.9% over the study period.

Conclusions

The hospital volume of pancreatectomies has increased substantially, while complications and postoperative mortality have remained at acceptable levels. Long-term survival and resection rate of PDAC patients showed notable improvement over two decades.

Transpancreatic biliary sphincterotomy versus double guidewire in difficult biliary cannulation: a randomized controlled trial

BACKGROUND

Difficult biliary cannulation in endoscopic retrograde cholangiopancreatography (ERCP) increases the risk of post-ERCP pancreatitis (PEP). The purpose of this prospective, randomized, multicenter study was to compare two advanced rescue methods, transpancreatic biliary sphincterotomy (TPBS) and a double-guidewire (DGW) technique, in difficult common bile duct (CBD) cannulation.

METHODS

Patients with native papilla and planned CBD cannulation were recruited at eight Scandinavian hospitals. An experienced endoscopist attempted CBD cannulation with wire-guided cannulation. If the procedure fulfilled the definition of difficult cannulation and a guidewire entered the pancreatic duct, randomization to either TPBS or to DGW was performed. If the randomized method failed, any method available was performed. The primary end point was the frequency of PEP and the secondary end points included successful cannulation with the randomized method.

RESULTS

In total, 1190 patients were recruited and 203 (17.1 %) were randomized according to the study protocol (TPBS 104 and DGW 99). PEP developed in 14/104 patients (13.5 %) in the TPBS group and 16/99 patients (16.2 %) in the DGW group (P = 0.69). No difference existed in PEP severity between the groups. The rate of successful deep biliary cannulation was significantly higher with TPBS (84.6 % [88/104]) than with DGW (69.7 % [69/99]; P = 0.01).

CONCLUSIONS

In difficult biliary cannulation, there was no difference in PEP rate between TPBS and DGW techniques. TPBS is a good alternative in cases of difficult cannulation when the guidewire is in the pancreatic duct.

Macroscopic appearance of the major duodenal papilla influences bile duct cannulation: a prospective multicenter study by the Scandinavian Association for Digestive Endoscopy Study Group for ERCP

BACKGROUND AND AIMS

Certain appearances of the major duodenal papilla have been claimed to make cannulation more difficult during ERCP. This study uses a validated classification of the endoscopic appearance of the major duodenal papilla to determine if certain types of papilla predispose to difficult cannulation.

METHODS

Patients with a naïve papilla scheduled for ERCP were included. The papilla was classified into 1 of 4 papilla types before cannulation started. Time to successful bile duct cannulation, attempts, and number of pancreatic duct passages were recorded. Difficult cannulation was defined as after 5 minutes, 5 attempts, or 2 pancreatic guidewire passages.

RESULTS

A total of 1401 patients were included from 9 different centers in the Nordic countries. The overall frequency of difficult cannulation was 42% (95% confidence interval [CI], 39%-44%). Type 2 small papilla (52%; 95% CI, 45%-59%) and type 3 protruding or pendulous papilla (48%; 95% CI, 42%-53%) were more frequently difficult to cannulate compared with type 1 regular papilla (36%; 95% CI, 33%-40%; both P < .001). If an inexperienced endoscopist started cannulation, the frequency of failed cannulation increased from 1.9% to 6.3% (P < .0001), even though they were replaced by a senior endoscopist after 5 minutes.

CONCLUSIONS

The endoscopic appearance of the major duodenal papilla influences bile duct cannulation. Small type 2 and protruding or pendulous type 3 papillae are more frequently difficult to cannulate. In addition, cannulation might even fail more frequently if a beginner starts cannulation. These findings should be taken into consideration when performing studies regarding bile duct cannulation and in training future generations of endoscopists.

Prophylactic pancreatic duct stenting in severe acute necrotizing pancreatitis: a prospective randomized study

BACKGROUND

Pancreatic duct disruption is common and is associated with high morbidity in cases of acute necrotizing pancreatitis (ANP). In this study, we tested the feasibility and safety of prophylactic pancreatic duct stenting (PPDS) in ANP and compared PPDS with conservative treatment.

METHODS

We prospectively enrolled patients (aged 18 - 75 years) diagnosed with ANP between February 2011 and July 2015. These patients were prospectively randomized to receive PPDS or conservative treatment at two tertiary centers. PPDS was performed as soon as possible after randomization.

RESULTS

Concern regarding iatrogenic infections with pancreatic necrosis in the PPDS group prompted interim analysis, which confirmed a highly elevated risk. Thus, the trial was terminated prematurely for ethical reasons. Of the 11 patients in the PPDS group, all patients with successful pancreatic duct placement (5/5, 100 %) presented with infection, compared with only 3 of the 13 patients (23.1 %) in the conservative treatment group (P = 0.01). Analysis revealed success rates of 63.6 % for pancreatic duct cannulation, 45.5 % for pancreatic duct stenting, and 18.2 % for placement of a stent bridging the necrosis. Cannulation and stenting failures were due to duodenal edema and pancreatic duct stenosis.

CONCLUSIONS

PPDS in ANP is associated with an unacceptably high risk of pancreatic necrosis infection. In addition, the procedure is technically challenging due to duodenal edema and ductal stenosis.

How Well Planned Urgency Class Come True in The Emergency Surgery? Timing of Acute Care Surgery

BACKGROUND AND AIMS

Emergency surgery represents an essential aspect of surgical care, but little is known about realization of the planned emergency class. Different systems such as NCEPOD classification and Timing of Acute Care Surgery classification have been developed for the timing of the emergency surgery. The aim of the study was to find out how well planned urgency class is being implemented.

MATERIALS AND METHODS

The planned and realized waiting times for all emergency surgeries were studied during the 6-month period in the Oulu University Hospital. The catchment area of the hospital includes a population of 742,000. The urgency in the hospital is planned in a four-step scale: an extremely urgent (E) patient should be taken immediately to the operating theater. Class I urgency surgery should start within 3 h (180 min), class II within 8 h (480 min), and class III within 24 h (1440 min). Surgeon plans urgency at his discretion, and no specific urgency has been imposed on certain diagnoses thus the surgeon's perceptions of the illness or trauma affects the assessment.

RESULTS

Extreme urgent patients had an average waiting time of 26 min. For class I patient, the average waiting time was 59 min, while 93% of surgeries were started within the target time. For class II and class III patients, these figures were 337 min and 86% and 830 min and 78%, respectively.

CONCLUSION

With regard to urgency, the higher the degree of urgency, the greater the chance of the surgery being realized within the planned time.

Randomized multicenter study of multiple plastic stents vs. covered self-expandable metallic stent in the treatment of biliary stricture in chronic pancreatitis

BACKGROUND AND STUDY AIMS

The use of covered self-expandable metallic stents (cSEMS) in benign biliary indications is evolving. The aim of the study was to assess the safety and feasibility of cSEMS compared with multiple plastic stents in the treatment of benign biliary stricture (BBS) caused by chronic pancreatitis.

PATIENTS AND METHODS

This was a prospective, multicenter, randomized study of 60 patients with BBS caused by chronic pancreatitis. All patients received an initial plastic stent before randomization. At randomization, the stent was replaced either with a single cSEMS or three plastic stents. After 3 months, the position of the cSEMS was checked or another three plastic stents were added. At 6 months after randomization, all stents were removed. Clinical follow-up including abdominal ultrasound and laboratory tests were performed at 6 months and 2 years after stent removal.

RESULTS

Two patients dropped out of the cSEMS group before stent removal. In April 2014, the median follow-up was 40 months (range 1 - 66 months). The 2-year, stricture-free success rate was 90 % (95 % confidence interval [CI] 72 % - 97 %) in the plastic stent group and 92 % (95 %CI 70 % - 98 %) in the cSEMS group (P = 0.405). There was one late recurrence in the plastic stent group 50 months after stent removal. Stent migration occurred three times (10 %) in the plastic stent group and twice in the cSEMS group (7 %; P = 1.000).

CONCLUSION

A 6-month treatment with either six 10-Fr plastic stents or with one 10-mm cSEMS produced good long-term relief of biliary stricture caused by chronic pancreatitis.Study registered at ClinicalTrials.gov (NCT01085747).

Endoscopic transpapillary stenting for pancreatic fistulas after necrosectomy with necrotizing pancreatitis

BACKGROUND

Data concerning the incidence and treatment of pancreatic fistula after necrosectomy in severe acute necrotizing pancreatitis (SAP) are scarce. Our aim was to assess the incidence of pancreatic fistula, and the feasibility and results of endoscopic transpapillary stenting (ETS) in patients with SAP after necrosectomy.

METHODS

From January 2009 to December 2012 twenty-nine consecutive patients with SAP and necrosectomy in Oulu University Hospital were enrolled into this study. Five patients died before ETS because of the rapid progress of the disease and were, therefore, excluded.

RESULTS

ERP was performed for the remaining 24 patients demonstrating fistula in 22/24 patients (92 %). ETS was successful in 23 patients and the fistula closed in all of them after a median of 82 (2-210) days with acceptable morbidity and no procedure-related mortality.

CONCLUSION

All patients after necrosectomy for SAP seem to have internal or external pancreatic fistula. EST aimed at internal drainage of the necrosectomy cavity is a feasible and effective therapy in these patients.

Difficult cannulation as defined by a prospective study of the Scandinavian Association for Digestive Endoscopy (SADE) in 907 ERCPs

BACKGROUND

The definition of a "difficult" cannulation varies considerably in reports of endoscopic retrograde cholangiopancreatography (ERCP).

AIMS

To define a difficult cannulation, which translates into higher risk of post-ERCP pancreatitis.

PATIENTS AND METHODS

Prospective consecutive recording of 907 cannulations in Scandinavian centers done by experienced endoscopists. Inclusion: indication for biliary access in patients with intact papilla. Exclusion: acute non-biliary and chronic pancreatitis at time of procedure.

RESULTS

The primary cannulation succeeded in 74.9%, with median values for time 0.88 min (53 s), with two attempts and with zero pancreatic passages or injections. The overall cannulation success was 97.4% and post-ERCP pancreatitis (PEP) rate was 5.3%. The median time for all successful cannulations was 1.55 min (range 0.02-94.2). If the primary cannulation succeeded, the pancreatitis rate was 2.8%; after secondary methods, it rose to 11.5%. Procedures lasting less than 5 min had a PEP rate of 2.6% versus 11.8% in those lasting longer. With one attempt, the PEP rate was 0.6%, with two 3.1%, with three to four 6.1%, and with five and more 11.9%. With one accidental pancreatic guide-wire passage, the risk of the PEP was 3.7%, and with two passages, it was 13.1%.

CONCLUSIONS

If the increasing rate of PEP is taken as defining factor, the wire-guided cannulation of a native papilla can be considered difficult after 5 min, five attempts, and two pancreatic guide-wire passages when any of those limits is exceeded.

Strong claudin 5 expression is a poor prognostic sign in pancreatic adenocarcinoma

We investigated the expression of claudin 5 in 88 ductal adenocarcinomas of the pancreas. The results were correlated with patient prognosis, with claudin 5 expression in blood vessels, with the expression level of bcl2 and bax and with apoptosis. Claudin 5 expression was detected in 24 (38%) cases. It was not associated with tumour size or spread, but strong claudin 5 expression correlated with a worse survival (p = 0.005). Claudin 5 also associated with a higher extent of apoptosis and greater expression of bax protein. In the tumour vasculature, some vessels displayed a loss of claudin 5 expression. The presence of this loss was associated with tumour grade and the presence of nodal metastases (p = 0.02, p = 0.022, respectively). These results indicate that claudin 5 is upregulated in a proportion of pancreatic ductal adenocarcinomas. The association of strong claudin 5 expression with a worse survival is in line with some earlier reports indicating that this protein is involved with increased locomotion and more aggressive spread of carcinomas. The association of claudin 5 with apoptosis and bax might be due to stronger cellular kinetics found in such tumours. The loss of claudin 5 expression in the tumour vasculature points to a leaky vessel type; this might also ease the access of tumours to vessels and be reflected in its association with the presence of nodal metastases.

Nuclear Nrf2 expression is related to a poor survival in pancreatic adenocarcinoma

The aim of this study was to investigate the expression of Nrf2, sulfiredoxin and DJ1 in pancreatic cancer. The expression of Nrf2, sulfiredoxin and DJ1 was studied immunohistochemically in a large set of pancreatic adenocarcinomas consisting of 103 cases. Eighty six percent of the cases showed cytoplasmic Nrf2 and 24% nuclear Nrf2 positivity. Sulfiredoxin positivity was observed in 54% and DJ1 positivity in all cases. Nuclear Nrf2 positivity had an association with sulfiredoxin (p=0.019) and was associated with a poor survival (p=0.010). Stage IV tumors tended to have a more nuclear Nrf2 expression (p=0.080). DJ1 expression was more often found in well-differentiated tumors (p=0.012), and DJ1 expression was associated with better survival (p=0.020). According to the results, nuclear Nrf2 expression predicts a worse survival in pancreatic adenocarcinoma, which is in keeping with its protection of cells against oxidative or xenobiotic stress. In accordance with Nrf2's regulation of the synthesis of sulfiredoxin, there was an association between them (p=0.019). DJ1 had no association with Nrf2, and its expression predicted a better survival of patients.

Self organization of a massive document collection

This article describes the implementation of a system that is able to organize vast document collections according to textual similarities. It is based on the self-organizing map (SOM) algorithm. As the feature vectors for the documents statistical representations of their vocabularies are used. The main goal in our work has been to scale up the SOM algorithm to be able to deal with large amounts of high-dimensional data. In a practical experiment we mapped 6,840,568 patent abstracts onto a 1,002,240-node SOM. As the feature vectors we used 500-dimensional vectors of stochastic figures obtained as random projections of weighted word histograms.

How to cannulate? A survey of the Scandinavian Association for Digestive Endoscopy (SADE) in 141 endoscopists

Cannulation of the papilla vateri represents an enigmatic first step in endoscopic retrograde cholangiopancreaticography (ERCP). In light of falling numbers of (diagnostic) ERCP and novel techniques, e.g. short-wire system, we were interested in the approach novice and experienced endoscopist are taking; especially, what makes a papilla difficult to cannulate and how to approach this. We devised a structured online questionnaire, sent to all endoscopists registered with SADE, the Scandinavian Association for Digestive Endoscopy. A total of 141 responded. Of those, 49 were experienced ERCP-endoscopists (>900 ERCPs). The first choice of cannulation is with a sphincterotome and a preinserted wire. Both less experienced and more experienced endoscopists agreed on the criteria to describe a papilla difficult to cannulate and both would choose the needle-knife sphincterotomy (NKS) to get access to the bile duct. The less experienced used more "upward" NKS, whereas the more experienced also used the "downward" NKS technique. This survey provides us with a database allowing now for a more differentiated view on cannulation techniques, success, and outcome in terms of pancreatitis.

Safety of Erlangen precut papillotomy: an analysis of 1044 consecutive ERCP examinations in a single institution

GOALS AND BACKGROUND

There is controversy about the ideal utilization of precut papillotomy in endoscopic retrograde cholangiopancreatography examinations. Almost all reports in the literature concentrate on needle knife precut papillotomy, reporting a wide range of complications. We have used Erlangen precut papillotomy in our institution and our aim was to compare the safety of Erlangen precut papillotomy to standard free cannulation technique. The influence of precutting on the deep biliary cannulation rate was also recorded.

STUDY

Over a period of 48 months a total of 602 out of 1044 consecutive endoscopic retrograde cholangiopancreatography examinations fulfilled the inclusion criteria. Patients with an intact papilla who required biliary cannulation were screened. The cohort was divided into a nonprecut group (n=481) and a precut group (n=121). The standard technique included free biliary cannulation with a tapered-tip cannula. An Erlangen type papillotome was used for precutting. Complications, success rate of cannulation, and hyperamylasemia were recorded.

RESULTS

Complication rates were similar in the 2 groups (nonprecut 7.1% vs. precut 8.3%, P=0.7). Hyperamylasemia was more common in the precut group (13.3% vs. 31.3%, P<0.001). The final deep biliary cannulation rate after precut papillotomy in cases with problematic cannulation was 98.2%.

CONCLUSIONS

Erlangen precut papillotomy results in a high deep biliary cannulation rate with no increased risk of complications when compared to cannulation using standard techniques.

Adenoma of the papillae of Vater. Report of eleven cases

Eleven patients with a preoperative diagnosis of adenoma of the papillae of Vater were followed up during the fifteen-year period from 1984 till 1998 in the Oulu University Hospital. Seven patients were treated primarily by transduodenal excision without any recurrences so far. One of these seven patients was found to have adenocarcinoma in a histological examination. Active surgery for adenoma of the papillae of Vater is recommended because of the precancerous nature of the lesion, and because malignancy cannot always be detected by endoscopic biopsies. Transduodenal excision could be recommend for patients at high operative risk, especially in cases with small adenomas and low-grade dysplasia, where histologically free resection margins can be achieved, but pancreaticoduodenectomy should still be performed on patients at low operative risk.

Liver resection of noncolorectal secondaries

BACKGROUND AND OBJECTIVES

Hepatic resection of noncolorectal metastases appears to be performed with increasing frequency. Reported experience is limited and indications are controversial.

METHODS

Retrospective review of curative hepatic resection in 32 patients (median age 58 years) during 1970-1995. The primary tumor was a carcinoid in seven patients, other endocrine tumor in five patients, malignant melanoma in three patients, stomach cancer in three patients, exocrine pancreatic cancer in two patients, gynecological cancer in two patients, sarcoma in two patients, and miscellaneous in eight patients. Seven patients (22%) had bilobar disease and 12 patients (38%) had extrahepatic growth.

RESULTS

Median survival was 32 months, and 5-year actuarial survival rate was 36% (including operative mortality). Median survival in the endocrine (n = 12) and nonendocrine (n = 20) groups was 72 and 18 months, respectively (corresponding 5-year survival rates were 56 and 25%) (P = 0.16). Prognostic factors could not be established in either group. It is, however, noteworthy that no patient with nonendocrine secondaries and more than one liver tumor or extrahepatic disease survived for 5 years. Major complications were seen in eight patients (25%), including three postoperative deaths (operative mortality 9%) occurring during the first 5 years of the study period.

CONCLUSIONS

Hepatic resection of metastases from endocrine primary tumors was followed by long-term survival in a substantial proportion of patients. Long-term survival for patients with nonendocrine tumors was observed only when there was a single liver tumor and no extrahepatic growth. Further experience is needed for definition of resection criteria.

Radiological findings in biliary fistula and gallstone ileus

PURPOSE

Biliary fistula and gallstone ileus are rarely found. The diagnosis is difficult and may be delayed until operation. We reviewed the radiological findings in a retrospective material.

MATERIAL AND METHODS

The cases of 16 patients treated for biliary fistula were analyzed with respect to findings at imaging. Ten patients had a spontaneous fistula. Nine of them had an internal bilioduodenal fistula and one had an external fistula with stones passing through a subcutaneous abscess. Five patients also had gallstone ileus and one patient a rare gastric outlet obstruction caused by a gallstone (Bouveret's syndrome). Six patients had an iatrogenic fistula. One of them had internal bile ascites and 5 an external fistula, one of which was a biliocystic fistula resulting from attempted hepatic cyst sclerotherapy.

RESULTS

Various imaging modalities were used and there was often a delay in the diagnosis. Imaging did not show the fistula itself in any of the spontaneous cases. However, a nonvisualized or shrunken gallbladder seen at US often coexisted in these cases. CT yielded the diagnosis in one case of gallstone ileus, and a Gastrografin meal yielded it in the case of Bouveret's syndrome. Fistulography and cholangiography provided a correct diagnosis of fistula in all cases of iatrogenic biliocutaneous fistulas.

CONCLUSION

Patients with biliary fistula usually undergo examinations with nonspecific results. The imaging findings could be more specific if the possibility of this diagnosis were remembered.

Radiological findings in biliary fistula and gallstone ileus

PURPOSE

Biliary fistula and gallstone ileus are rarely found. The diagnosis is difficult and may be delayed until operation. We reviewed the radiological findings in a retrospective material.

MATERIAL AND METHODS

The cases of 16 patients treated for biliary fistula were analyzed with respect to findings at imaging. Ten patients had a spontaneous fistula. Nine of them had an internal bilioduodenal fistula and one had an external fistula with stones passing through a subcutaneous abscess. Five patients also had gallstone ileus and one patient a rare gastric outlet obstruction caused by a gallstone (Bouveret's syndrome). Six patients had an iatrogenic fistula. One of them had internal bile ascites and 5 an external fistula, one of which was a biliocystic fistula resulting from attempted hepatic cyst sclerotherapy.

RESULTS

Various imaging modalities were used and there was often a delay in the diagnosis. Imaging did not show the fistula itself in any of the spontaneous cases. However, a nonvisualized or shrunken gallbladder seen at US often coexisted in these cases. CT yielded the diagnosis in one case of gallstone ileus, and a Gastrografin meal yielded it in the case of Bouveret's syndrome. Fistulography and cholangiography provided a correct diagnosis of fistula in all cases of iatrogenic biliocutaneous fistulas.

CONCLUSION

Patients with biliary fistula usually undergo examinations with nonspecific results. The imaging findings could be more specific if the possibility of this diagnosis were remembered.

Intraabdominal abscess formation after major liver resection

A series of 138 major liver resections undertaken between 1971 and 1987 were reviewed. Intrabdominal abscesses developed in 11 (8%) patients, a mean of 23 days (range 10-42) after operation and two died (mortality 18%). Eight developed after 63 right hepatectomies, two after 24 right lobectomies, one after 34 left hepatectomies and none after left lobectomies (17). Patients who developed intra-abdominal abscesses underwent significantly longer operations (mean (SEM) 400 (48) compared with 275 (21) min) (p less than 0.05) and had significantly more bleeding during the operation (7,600 (1,750) compared with 3,200 (430), p less than 0.01) than those who did not. The amounts recovered from the abdominal drains, both before and after the diagnosis, were comparatively greater in patients with abdominal abscesses. Antibiotic prophylaxis was given to 10 of 11 patients who did and 89 of 127 patients who did not, form abscesses. We conclude that the risk of intra-abdominal abscess formation after major liver resection is increased: when a large amount of liver tissue is removed (right hepatectomy or lobectomy); when there is a lot of intraoperative bleeding; and when the operation takes a long time. Antibiotic prophylaxis did not affect the risk of abscess formation this series.