Surgical approach and perioperative complications determine short-term outcomes in patients with insulinoma: results of a bi-institutional study

Robotic Versus Laparoscopic Versus Open Surgery for Non-Metastatic Pancreatic Neuroendocrine Tumors (pNETs): A Systematic Review and Network Meta-Analysis

Background: This systematic review, using pairwise and network meta-analyses, aimed to compare the intraoperative, short-term, and long-term postoperative outcomes of minimally invasive surgery (MIS) and open surgery (OS) for the management of pancreatic neuroendocrine tumors (pNETs). Methods: Studies reporting on the effects of robotic, laparoscopic, and open surgery on pNETs published before November 2023 on PubMed, Scopus, and CENTRAL were analyzed. Results: Thirty-two studies with 5379 patients were included in this review, encompassing 2251 patients undergoing MIS (1334 laparoscopic, 508 robotic, and 409 unspecified MIS) and 3128 patients undergoing OS for pNETs management. Pairwise meta-analysis revealed that the MIS group had a significantly shorter length of hospital stay ((a low certainty of evidence), MD of -4.87 (-6.19 to -3.56)); less intraoperative blood loss ((a low certainty of evidence), MD of -108.47 (-177.47 to -39.47)); and decreased tumor recurrence ((a high certainty of evidence), RR of 0.46, 95% CI (0.33 to 0.63)). Subgroup analysis indicated a higher R0 resection rate and prolonged operative time for laparoscopic surgery than for OS. The network meta-analysis ranked the robotic approach as superior in terms of the length of hospital stay, followed by the laparoscopic and OS arms. Furthermore, it favored both MIS approaches over OS in terms of the R0 resection rate. No significant differences were found in severe postoperative complications, postoperative fistula formation, mortality, readmission, reoperation, or conversion rates. Conclusions: This review supports the safety of MIS for the treatment of pNETs. However, the varying certainty of evidence emphasizes the need for higher-quality studies.

Outcomes of endoscopic ultrasound-guided ablation and minimally invasive surgery in the treatment of pancreatic insulinoma: a systematic review and meta-analysis

Background and aims

Most pancreatic insulinomas can be treated by minimally invasive modalities. The aim of this meta-analysis was to assess the clinical outcomes of endoscopic ultrasound (EUS)-guided ablation and minimally invasive surgery (MIS) in the treatment of pancreatic insulinoma.

Materials and methods

Online databases were searched for relevant studies. The primary aim was to compare the rates of adverse events (AEs) and the secondary aims were to compare the clinical and technical success rates, length of hospital stays, and symptom recurrence rates between EUS and MIS approaches.

Results

Eight studies with 150 patients were identified that reported EUS-guided ablation outcomes, forming the EUS group, and 9 studies with 236 patients reported MIS outcomes, forming the MIS group. The pooled median age of the included patients in the EUS group was greater than that of the MIS group (64.06 vs. 44.98 years old, p < 0.001). Also, the technical success rate was significantly higher in the EUS group (100% vs. 96.6%, p = 0.025), while the clinical success was significantly higher (6%) in the MIS group (94% vs. 98.7%, p = 0.021). The AE rates (18.7% vs. 31.1%, p = 0.012) and severe AE rates (1.3% vs. 7.9%, p = 0.011) were significantly lower in the EUS group. The median length of hospital stay in the EUS group (2.68 days, 95% CI: 1.88-3.48, I2 = 60.3%) was significantly shorter than in the MIS group (7.40 days, 95% CI: 6.22-8.58, I2 = 42.2%, p < 0.001). The recurrence rate was significantly higher in the EUS group (15.3% vs. 1.3%, p < 0.001).

Conclusions

EUS-guided ablation is associated with a lower AE rate and a shorter length of hospital stay, but a higher recurrence rate for the treatment of insulinoma compared with MIS. The EUS approach may be an alternative, even first-line, treatment for poor surgery candidates.

Updated Meta-analysis of Minimally Invasive Versus Open Surgery for Pancreatic Neuroendocrine Neoplasms

OBJECTIVES

The aim of this study was to compare the short-term and long-term outcomes of minimally invasive surgery (MIS) with those of open pancreas surgery (OPS) for the treatment of pancreatic neuroendocrine neoplasms (pNENs).

METHODS

Studies reporting the effects of MIS and OPS for pNENs, published on PubMed, Embase, and Cochrane Library before May 2020 were reviewed.

RESULTS

Seventeen cohort studies with a total of 1853 patients were eligible for analysis, including 655 patients in the MIS group and 1198 patients in the OPS group. The estimated blood loss, postoperative hospitalization time, overall complications, severe complications, spleen preservation, mortality, and recurrence in the MIS group were lower than those in the OPS group. The R0 rate, 3-year overall survival (OS), and 5-year OS in the MIS group were higher than those in the OPS group. There were no significant differences in operative time, postoperative pancreatic fistula, clinical postoperative pancreatic fistula, postoperative bleeding, reoperation, readmission, and 1-year OS.

CONCLUSIONS

Minimally invasive surgery can reach lower recurrence rate, higher long-term survival rate, and better outcomes in terms of estimated blood loss, postoperative hospitalization time, R0 rate, mortality, overall complications, and severe complications for pNENs. More high quality studies need to be conducted for further verification.

Minimally Invasive Versus Open Pancreatectomies for Pancreatic Neuroendocrine Neoplasms: A Propensity-Score-Matched Study

BACKGROUND

Pancreatic neuroendocrine neoplasms (PNENs) are increasingly prevalent with modern imaging, and surgical excision remains mainstay of treatment. This study aims to perform a propensity-score-matched (PSM) comparison of perioperative and oncologic outcomes following minimally invasive pancreatectomy (MIP) versus open pancreatectomy (OP) for PNEN.

METHODS

A retrospective review was performed on patients who underwent curative-intent surgery for PNEN at Singapore General Hospital from 1997 to 2018. A 1:1 PSM was performed between MIP and OP, after which both groups were balanced for baseline variables.

RESULTS

We studied 134 patients who underwent surgery (36 MIP and 98 OP) for PNEN. Propensity-score-matched comparison between 35 MIP and 35 OP patients revealed that the MIP group had a longer operating time (MD = 75.0, 95% CI 15.2 to 134.8, P = 0.015), lower intraoperative blood loss (MD = - 400.0, 95% CI - 630.5 to - 169.5, P = 0.001), shorter median postoperative stay (MD = - 1.0, 95% CI - 1.9 to - 0.1, P = 0.029) and shorter median time to diet (MD = - 1.0, 95% CI - 1.9 to - 0.1, P = 0.039). There were no differences between both groups for short-term adverse outcomes and oncologic clearance. Overall survival (HR = 0.84, 95% CI 0.28 to 2.51, P = 0.761) and disease-free survival (HR = 0.57, 95% CI 0.20 to 1.64, P = 0.296) were comparable.

CONCLUSION

MIP is a safe and feasible approach for PNEN and is associated with a lower intraoperative blood loss, decreased postoperative stay and time to oral intake, at the expense of a longer operative time compared to OP.

Minimally invasive versus open pancreatic enucleation. Systematic review and meta-analysis of surgical outcomes

Parenchymal sparing procedures are gaining interest in pancreatic surgery and recent studies have reported that minimally invasive pancreatic enucleation may be associated with enhanced outcomes when compared with traditional surgery. By meta-analyzing the available data from the literature, minimally invasive surgery is not at higher risk of pancreatic fistula and offers a number of advantages over conventional surgery for pancreatic enucleation.

Natural History of MEN1 GEP-NET: Single-Center Experience After a Long Follow-Up

BACKGROUND

The multiple endocrine neoplasia type 1 syndrome (MEN1) natural history is poorly evaluated, and few single-institution experiences about hereditary gastroenteropancreatic neuroendocrine tumors (GEP-NET) are reported. Our purpose is to analyze the role of GEP-NET in MEN1-related death, as well as the behavior of these lesions during follow-up.

METHODS

The study population consists of 77 patients diagnosed with MEN1 GEP-NET, regularly followed up since 1990. Extensive clinical data were prospectively recorded. Statistical analysis was performed both on the whole population of 77 patients and on two subgroups including patients who, during the long lasting study period, underwent GEP-NET surgery (50 pts) and who did not (27 pts), respectively.

RESULTS

Twenty-five males (32.5%) and 52 females (67.5%) were enrolled. Sixty-four patients had MEN1 family history (83.1%), and genetic mutation was detected in 67 cases (87%). The mean age at GEP-NET diagnosis was 41.4 years (SD = 13.6); 16 patients (20.8%) had GEP-NET diagnosed before age 30 and 12 cases (15.6%) before 1996. The mean interval time between MEN1 diagnosis and GEP-NET detection was 5.7 years (range -11/37; SD = 8.1 years). Overall, the mean follow-up time from MEN1 diagnosis was 15.8 years (SD = 9.7 years) and from GEP-NET diagnosis was 9.6 years (SD = 6.9 years). Gastrinoma was the most frequent functioning GEP-NET and pancreatoduodenectomy the most adopted surgery. GEP-NET progression affected 12 patients within the non-surgical group, while 18 subjects developed progression after surgery.

CONCLUSIONS

Our single-center data provide information on epidemiologic, clinical and pathological features of GEP-NET in MEN1 making possible to clarify their natural history.

Laparoscopic management of neuroendocrine tumors: state-of-the-art

Over recent years, minimally invasive pancreatic resections have increasingly been reported in the literature. Even though pancreatic surgery is still considered a challenge for surgeons due to its technical difficulties and high morbidity, the consolidation of minimally invasive pancreatic surgery has included the treatment of pancreatic neuroendocrine tumors (PNETs). This article presents a systematic review of the literature with regards to the laparoscopic treatment of PNETs in order to assess the safety and feasibility of laparoscopic pancreatic resections.

Systematic review and meta-analysis on laparoscopic pancreatic resections for neuroendocrine neoplasms (PNENs)

The safety of laparoscopic resections (LPS) of pancreatic neuroendocrine neoplasms (PNENs) has been well established in the literature. Areas covered: Studies conducted between January 2003 and December 2015 that reported on LPS and open surgery (OPS) were reviewed. The primary outcomes were the rate of post-operative complications and the length of hospital stay (LoS) after laparoscopic and open surgical resection. The rate of recurrence was the secondary outcome. Eleven studies were included with a total of 907 pancreatic resections for PNENs, of whom, 298 (32.8%) underwent LPS and 609 (67.2%) underwent open surgery. LPS resulted in a significantly shorter LoS (p < 0.0001) and lower blood loss (p < 0.0001). The meta-analysis did not show any significant difference in the pancreatic fistula rate, recurrence rate or post-operative mortality between the two groups. Expert commentary: LPS is a safe approach even for PNENs and it is associated with a shorter LoS.

Diagnosis and surgical management of insulinomas in 33 consecutive patients at a single institution

PURPOSE

The purpose of this study was to evaluate the diagnosis and surgical management of insulinomas in a single-center setting.

METHODS

Demographic details, clinical presentation, preoperative diagnosis, surgical strategy, and outcomes of 33 consecutive patients who underwent surgery for insulinoma were analyzed retrospectively.

RESULTS

The median time from the first onset of symptoms to diagnosis was 24 months (range 3 days to 50 years). All cases presented with Whipple's triad and had a fasting insulin to glucose ratio higher than 0.33. The preoperative detection rates of transabdominal ultrasonography, CT, MRI, and EUS were 22 % (2/9), 72 % (23/32), 75 % (9/12), and 80 % (4/5), respectively. Intraoperative manual palpation localized all cases. Enucleation was performed in 58 % of cases (19/33), partial pancreatic resection in 39 % (13/33), and enucleation plus partial resection in 3 % (1/33). Pancreatic fistula was the most common complication and occurred in 15 patients (45 %), including seven grade A, five grade B, and three grade C fistulas. There was no mortality. When compared with partial pancreatectomy, enucleation held a significant advantage in operative time and operative bleeding, with no significant differences in demographic data and postoperative complications. During a median follow-up period of 32 months, two patients were lost to follow-up and the remaining 31 patients were without evidence of recurrence.

CONCLUSIONS

A fasting insulin release index larger than 0.3 is a reliable indicator for the diagnosis of insulinoma. Intraoperative palpation by an experienced surgeon can effectively complement an uncertain preoperative localization. Compared with partial pancreatic resection, enucleation showed significant benefit in terms of intraoperative blood loss and operation time.

Pancreatic insulinomas: Laparoscopic management

Insulinomas are rare pancreatic neuroendocrine tumors that are most commonly benign, solitary, and intrapancreatic. Uncontrolled insulin overproduction from the tumor produces neurological and adrenergic symptoms of hypoglycemia. Biochemical diagnosis is confirmed by the presence of Whipple’s triad, along with corroborating measurements of blood glucose, insulin, proinsulin, C-peptide, β-hydroxybutyrate, and negative tests for hypoglycemic agents during a supervised fasting period. This is accompanied by accurate preoperative localization using both invasive and non-invasive imaging modalities. Following this, careful preoperative planning is required, with the ensuing procedure being preferably carried out laparoscopically. An integral part of the laparoscopic approach is the application of laparoscopic intraoperative ultrasound, which is indispensable for accurate intraoperative localization of the lesion in the pancreatic region. The extent of laparoscopic resection is dependent on preoperative and intraoperative findings, but most commonly involves tumor enucleation or distal pancreatectomy. When performed in an experienced surgical unit, laparoscopic resection is associated with minimal mortality and excellent long-term cure rates. Furthermore, this approach confers equivalent safety and efficacy rates to open resection, while improving cosmesis and reducing hospital stay. As such, laparoscopic resection should be considered in all cases of benign insulinoma where adequate surgical expertise is available.

First surgery for pancreatic neuroendocrine tumours in a patient with MEN1: enucleation versus disease-modifying surgery

Pancreatic neuroendocrine tumours (PNETs) are the second most common manifestation of MEN1, affecting up to 80% of patients. The secretion of peptide hormones by PNETs causes clinical syndromes requiring therapeutic intervention. Malignant progression of PNETs is a leading cause of mortality in patients with MEN1. The goal of surgery, when required, is to alleviate a biochemical syndrome or to treat established tumour(s) to reduce the risk of local progression or metastases against the background of preservation of pancreatic function. Determining the need and optimum timing for an operative intervention is complex and requires an approach individualized for each patient. When a clinically significant biochemical syndrome is confirmed, the time course to surgery is clear. In patients with a potentially malignant PNET, the decision as to when to intervene is more challenging. In all cases surgical treatment carries the potential for harm, of more than usual concern because many of the patients are young. In this study, we explain an approach to the surgical treatment of MEN1 patients with biochemical or radiological evidence of PNETs where other manifestations of the syndrome are either treated or controlled and the patient lacks comorbidity that would preclude pancreatic surgery. In each scenario we present, a normal serum gastrin will be assumed as the surgical approach to this usually duodenal manifestation of MEN1 is significantly different to the management of other PNETs.

Multifocal Insulinoma in Pancreas and Effect of Intraoperative Ultrasonography

Insulinoma is the most frequently seen functional pancreatic neuroendocrine tumor. The incidence of multifocal insulinoma is lower than 10%. Its treatment is direct or laparoscopic excision. The present case was examined with the findings of hypoglycemia and hypercalcemia, and as there was high insulin and C-peptide levels the initial diagnosis was insulinoma. The case was investigated in terms of MEN 1. During preoperative screening for localization, there was one focus in the head of the pancreas in the abdominal tomography and two foci in endoscopic ultrasonography. No other focus was detected through intraoperative visual or manual palpation. However, five foci were detected during operation by intraoperative ultrasonography. The relation of masses with the main pancreatic canal was evaluated and they were excised by enucleation method. There was no recurrence during the postoperative 18-month follow-up of the patient. As a result, during treatment for insulinoma, it should be kept in mind that there might be multifocal foci. In all insulinomas, the whole pancreas should be evaluated with intraoperative ultrasonography because none of the current preoperative diagnostic methods are as sensitive as manual palpation of pancreas and intraoperative ultrasonography. The intraoperative detection of synchronous five foci in pancreas is quite a rare condition.

Assessing the short- and long-term outcomes after resection of benign insulinoma

BACKGROUND

Insulinoma is a rare functional pancreatic neuroendocrine tumour (NET) believed to have an excellent long-term outcome, but few studies have solely focused on this issue after apparently curative resection. This study aimed to assess post-operative and long-term outcomes after resection of benign insulinomas.

METHODS

From 1998 to 2013, 36 consecutive patients with insulinomas underwent surgery. Three patients had multiple endocrine neoplasia type-1 (MEN-1). Demographics, operative findings, tumour grade (2010 World Health Organization (WHO) NET classification), post-operative pancreatic fistula (POPF) grade (International Study Group of Pancreatic Fistula (ISGPF)), complications and recurrence were analysed.

RESULTS

Eighteen (50%) had enucleation while the rest underwent pancreatic resection. The majority (86.1%) of insulinomas belonged to WHO NET grade G1. POPF occurred in 58.3% of patients while clinical fistula (ISGPF grades B and C) occurred in 19.4%. One (2.8%) patient required reoperation. The occurrence of POPF was not related to type of resection or surgical approach. There was no perioperative mortality. After a mean follow-up of 83.6 months, two patients (5.7%) developed disease recurrence at 34.4 and 131.9 months after initial surgery. No patients developed distant metastasis. The 10- and 15-year disease-free rates were 95.6 and 85.4%, respectively.

CONCLUSION

POPF occurred frequently and posed a significant morbidity after resection of insulinoma. However, it occurred independently of type of resection or surgical approach. Although the immediate cure rate after resection was high (100%), long-term disease recurrence in sporadic (non-MEN-1) cases was not insignificant. Regular long-term follow-up is recommended.

Laparoscopic versus open pancreas resection for pancreatic neuroendocrine tumours: a systematic review and meta-analysis

BACKGROUND

Over the last decade laparoscopic pancreatic surgery (LPS) has emerged as an alternative to open pancreatic surgery (OPS) in selected patients with neuroendocrine tumours (NET) of the pancreas (PNET). Evidence on the safety and efficacy of LPS is available from non-comparative studies.

OBJECTIVES

This study was designed as a meta-analysis of studies which allow a comparison of LPS and OPS for resection of PNET.

METHODS

Studies conducted from 1994 to 2012 and reporting on LPS and OPS were reviewed. Studies considered were required to report on outcomes in more than 10 patients on at least one of the following: operative time; hospital length of stay (LoS); intraoperative blood loss; postoperative morbidity; pancreatic fistula rates, and mortality. Outcomes were compared using weighted mean differences and odds ratios.

RESULTS

Eleven studies were included. These referred to 906 patients with PNET, of whom 22% underwent LPS and 78% underwent OPS. Laparoscopic pancreatic surgery was associated with a lower overall complication rate (38% in LPS versus 46% in OPS; P < 0.001). Blood loss and LoS were lower in LPS by 67 ml (P < 0.001) and 5 days (P < 0.001), respectively. There were no differences in rates of pancreatic fistula, operative time or mortality.

CONCLUSIONS

The nature of this meta-analysis is limited; nevertheless LPS for PNET appears to be safe and is associated with a reduced complication rate and shorter LoS than OPS.

The surgical management of insulinomas in children

PURPOSE

Insulinomas are rare pediatric tumors for which optimal localization studies and management remain undetermined. We present our experience with surgical management of insulinomas during childhood.

METHODS

A retrospective review was performed of patients who underwent surgical management for an insulinoma from 1999 to 2012.

RESULTS

The study included eight patients. Preoperative localization was successful with abdominal ultrasound, abdominal CT, endoscopic ultrasound, or MRI in only 20%, 28.6%, 40%, and 50% of patients, respectively. Octreotide scan was non-diagnostic in 4 patients. For diagnostic failure, selective utilization of 18-Fluoro-DOPA PET/CT scanning, arterial stimulation/venous sampling, or transhepatic portal venous sampling were successful in insulinoma localization. Intraoperatively, all lesions were identified by palpation or with the assistance of intraoperative ultrasound. Surgical resection using pancreas sparing techniques (enucleation or distal pancreatectomy) resulted in a cure in all patients. Postoperative complications included a pancreatic fistula in two patients and an additional missed insulinoma in a patient with MEN-1 requiring successful reoperation.

CONCLUSIONS

Preoperative tumor localization may require many imaging modalities to avoid unsuccessful blind pancreatectomy. Intraoperative palpation with the assistance of ultrasound offers a reliable method to precisely locate the insulinoma. Complete surgical resection results in a cure. Recurrent symptoms warrant evaluation for additional lesions.

Is laparoscopic approach for pancreatic insulinomas safe? Results of a systematic review and meta-analysis

BACKGROUND

No consensus exists as to whether laparoscopic treatment for pancreatic insulinomas (PIs) is safe and feasible. The aim of this meta-analysis was to assess the feasibility, safety, and potential benefits of laparoscopic approach (LA) for PIs. The abovementioned approach is also compared with open surgery.

METHODS

A systematic literature search (MEDLINE, EMBASE, Cochrane Library, Science Citation Index, and Ovid journals) was performed to identify relevant articles. Articles that compare the use of LA and open approach to treat PI published on or before April 30, 2013, were included in the meta-analysis. The evaluated end points were operative outcomes, postoperative recovery, and postoperative complications.

RESULTS

Seven observational clinical studies that recruited a total of 452 patients were included. The rates of conversion from LA to open surgery ranged from 0%-41.3%. The meta-analysis revealed that LA for PIs is associated with reduced length of hospital stay (weighted mean difference, -5.64; 95% confidence interval [CI], -7.11 to -4.16; P < 0.00001). No significant difference was observed between LA and open surgery in terms of operation time (weighted mean difference, 2.57; 95% CI, -10.91 to 16.05; P = 0.71), postoperative mortality, overall morbidity (odds ratio [OR], 0.64; 95% CI, 0.35-1.17; P = 0.14], incidence of pancreatic fistula (OR, 0.86; 95% CI, 0.51-1.44; P = 0.56), and recurrence of hyperglycemia (OR, 1.81; 95% CI, 0.41-7.95; P = 0.43).

CONCLUSIONS

Laparoscopic treatment for PIs is a safe and feasible approach associated with reduction in length of hospital stay and comparable rates of postoperative complications in relation with open surgery.

Gastroenteropancreatic neuroendocrine tumors in multiple endocrine neoplasia type 1

We reviewed the literature about entero-pancreatic neuroendocrine tumors in Multiple Endocrine Neoplasia type 1 syndrome (MEN1) to clarify their demographic features, localization imaging, practice, and appropriate therapeutical strategies, analyzing the current approach to entero-pancreatic neuroendocrine tumors in MEN1. Despite the fact that hyperparathyroidism is usually the first manifestation of MEN1, the penetrance of these tumors is similar. They are characterized by multiplicity of lesions, variable expression of the tumors, and propensity for malignant degeneration. Both the histological type and the size of MEN1 neuroendocrine tumors correlate with malignancy. Monitoring of pancreatic peptides and use of imaging exams allow early diagnosis and prompt surgical treatment, resulting in prevention of metastatic disease and improvement of long-term survival. Surgery is often the treatment of choice for MEN1-neuroendocrine tumors. The rationale for surgical approach is to curtail malignant progression of the disease, and to cure the associated biochemical syndrome, should it be present.

Risk factors for postoperative pancreatic fistula in patients with insulinomas: analysis of 292 consecutive cases

BACKGROUND

Pancreatic fistula (PF) remains the most challenging complication in pancreatic surgery, yet few published studies have focused on the risk factors for postoperative PF in patients undergoing surgery for insulinomas.

METHODS

From January 1990 to February 2010, a total of 292 patients with insulinomas underwent surgery at Peking Union Medical College Hospital. Demographic data, intraoperative procedures, and postoperative data were collected. Particular attention was paid to variables associated with PF as defined by the International Study Group of Pancreatic Fistula (ISGPF). Univariate and multivariate analyses were used to identify possible risk factors for PF.

RESULTS

PF was found in 132 (45.2%) patients, of whom 90 were classified into ISGPF grade A, 33 grade B, and 9 grade C. Multivariate analysis showed that male patients (OR=2.56; P=0.007) and operative time >180 minutes (OR=3.756; P<0.0001) were independent risk factors for clinical PF. Pancreatic resection with stapler was a protective factor for both total PF (OR=0.022; P=0.010) and clinical PF (OR=0.097; P=0.007).

CONCLUSIONS

Male gender and operative time >180 minutes were independent risk factors for clinical PF, while pancreatic resection with a stapler was a protective factor. Whether body mass index (BMI) and other variables during operation are risk factors of PF needs further study.

Pancreatic endocrine tumors in multiple endocrine neoplasia type 1 syndrome: review of literature

OBJECTIVE

To analyze the surgical approach to multiple endocrine neoplasia type 1 (MEN 1)-related pancreatic endocrine tumors (PETs).

METHODS

We reviewed selected publications and our personal experience with MEN 1-associated PETs to delineate their general characteristics, current practice and controversies, preoperative imaging and intraoperative assessment, and appropriate therapeutic strategies including radical surgical procedures.

RESULTS

The penetrance of PETs in the setting of MEN 1 is similar to that of parathyroid tumors, even though hyperparathyroidism is usually the first manifestation of MEN 1 syndrome. In contrast with the sporadic counterparts, MEN 1-related PETs are characterized by an early onset, multiplicity of lesions, variable expression of the tumors, and propensity for malignant degeneration. Both the histologic type and the size of these tumors correlate with malignant potential.

CONCLUSION

The rationale for surgical considerations for these tumors is to curtail the malignant progression of the disease and to cure or aid in management of the associated biochemical syndromes. A surgical procedure is often the treatment of choice for PETs in patients with MEN 1. Monitoring of pancreatic peptides and use of diagnostic imaging allow an early pancreatic resection, in conjunction with prevention of metastatic PETs and improvement of long-term survival. Hepatic metastatic lesions can be successfully treated by surgical resection.

Setting the bar for laparoscopic resection of sporadic insulinoma

BACKGROUND

Laparoscopic insulinoma resection (LIR) for sporadic disease is increasingly supported as a feasible and safe operation in small series of patients. To determine whether LIR is an acceptable alternative to the open operation, it is necessary to compare LIR to historical controls. The purpose of this study was to identify the skills and technology needed for LIR and establish outcome standards.

METHODS

A database of patients with benign sporadic insulinoma who underwent an open procedure at the Mayo Clinic was reviewed for demographics, imaging, operative/pathology reports, and outcomes. Outcomes were compared to a world-wide meta-analysis of patients who had undergone LIR reported in the English literature between 1996 and 2009.

RESULTS

Two hundred fifteen patients underwent a primary open operation for benign sporadic insulinoma. Solitary tumors were found in 97%. Meta-analysis identified 232 patients who underwent LIR. The open and LIR groups underwent comparable operations that included enucleations (64 vs. 68%) and distal pancreatectomies (28 vs. 35%) (p = 0.06). The mean estimated blood loss, operating time, and length of stay were comparable between the open and LIR groups (p = NS). Pancreatic fistula occurred more often in the LIR group (24 vs. 11%, p < 0.05). A curative operation was performed in 98% of control patients and in 99% of the LIR group (p = NS).

CONCLUSIONS

Multiple insulinomas are rare and a focused resection guided by imaging may be performed. LIR is associated with an increased incidence of pancreatic fistula. Success of LIR will depend on accurate multimodality preoperative imaging, skilled use of lap-US to replace palpation for localization, and safe methods to dissect the tumor adjacent to the pancreatic duct.

Tailored imaging of islet cell tumors of the pancreas amidst increasing options

Pancreatic islet cell tumors are neuroendocrine tumors, which can produce hormones and can arise as part of multiple endocrine neoplasia type 1 or von-Hippel-Lindau-disease, two genetically well-defined hereditary cancer syndromes. Currently, technical innovation improves conventional and specific molecular imaging techniques. To organize the heterogeneous results described for the imaging of these tumors, we distinguished three indications (1) imaging of a patient with hormone hypersecretion, (2) search for a pancreatic primary in case of proven neuroendocrine cancer of unknown primary, and (3) screening of asymptomatic mutation carriers. We searched for publications on imaging of islet cell tumors between 1995 and January 2010 and defined a Level of Evidence (LOE) for the applicability of each technique. For each technique, data were analyzed in a Forest plot and arranged per imaging indication and tumor subtype. LOEs are weak for all imaging techniques. Analyses indicate a prominent role for endoscopic ultrasound for all three indications.

Laparoscopic surgery for pancreatic tumors

The rapid growth of minimally invasive technology and experience in recent decades has revolutionized many aspects of oncologic surgery. Adoption of laparoscopic pancreatectomy has been slow due to the inherent anatomic complexity of pancreatic surgery, as well as concerns of perioperative complications and compromised oncologic results. With increasing surgeon experience and growing data, laparoscopic pancreatic resection is generating considerable attention and enthusiasm. This article provides an overview of laparoscopic pancreatic tumor surgery with respect to tumor biology and technical approaches. Current applications of laparoscopic approaches to left pancreatectomy, tumor enucleation, central pancreatectomy, and pancreaticoduodenectomy for treatment of pancreatic tumors are considered in light of available evidence demonstrating feasibility, safety, and oncologic efficacy. Future directions in minimally invasive pancreatic surgery are explored.

Neuroendocrine tumors of the pancreas

Pancreatic endocrine tumors are rare neoplasms accounting for less than 5% of pancreatic malignancies. They are broadly classified into either functioning tumors (insulinomas, gastrinomas, glucagonomas, VIPomas, and somatostatinomas) or nonfunctioning tumors. The diagnosis of these tumors is difficult and requires a careful history and examination combined with laboratory tests and radiologic imaging. Signs and symptoms are usually related to hormone hypersecretion in the case of functioning tumors and to tumor size or metastases with nonfunctioning tumors. Surgical resection remains the treatment of choice even in the face of metastatic disease. Further development of novel diagnostic and treatment modalities offers potential to greatly improve quality of life and prolong disease-free survival for patients with pancreatic endocrine tumors.