Unresolved surgical issues in the management of patients with Zollinger-Ellison syndrome

Zollinger-Ellison syndrome: classical considerations and current controversies

Zollinger-Ellison syndrome (ZES) is an endocrinopathy characterized by gastrin-secreting tumors, responsible for causing the formation of multiple, refractory, and recurrent peptic ulcers in the distal duodenum and proximal jejunum. Two main variants have been described, sporadic and those found in association with parathyroid and pituitary tumors, a genetic disorder known as multiple endocrine neoplasia-1 (MEN-1). Biochemical serum evaluation for elevated gastrin, followed by radiological or nuclear localization of the primary lesion, is mandated for establishing diagnosis. The mainstays of treatment include management of hypersecretory state with medical suppression of gastric acid production and surgical resection of primary tumor for the prevention of malignant transformation and metastatic complications. Medical therapy with proton pump inhibitors has virtually eliminated the need for acid-reducing surgical procedures. Surgical approach to sporadic and MEN-1-associated ZES varies based on our understanding of the natural history of the condition and the probability of cure; however, resection to a negative microscopic margin is indicated in both cases. Postoperative surveillance involves measurement of gastrin level, followed by imaging if elevation is detected. Re-excision of recurrent or resection of metastatic disease is a subject of controversy; however, at the present time aggressive cytoreductive approach is favored.

Causes of death and prognostic factors in multiple endocrine neoplasia type 1: a prospective study: comparison of 106 MEN1/Zollinger-Ellison syndrome patients with 1613 literature MEN1 patients with or without pancreatic endocrine tumors

Multiple endocrine neoplasia type 1 (MEN1) is classically characterized by the development of functional or nonfunctional hyperplasia or tumors in endocrine tissues (parathyroid, pancreas, pituitary, adrenal). Because effective treatments have been developed for the hormone excess state, which was a major cause of death in these patients in the past, coupled with the recognition that nonendocrine tumors increasingly develop late in the disease course, the natural history of the disease has changed. An understanding of the current causes of death is important to tailor treatment for these patients and to help identify prognostic factors; however, it is generally lacking.To add to our understanding, we conducted a detailed analysis of the causes of death and prognostic factors from a prospective long-term National Institutes of Health (NIH) study of 106 MEN1 patients with pancreatic endocrine tumors with Zollinger-Ellison syndrome (MEN1/ZES patients) and compared our results to those from the pooled literature data of 227 patients with MEN1 with pancreatic endocrine tumors (MEN1/PET patients) reported in case reports or small series, and to 1386 patients reported in large MEN1 literature series. In the NIH series over a mean follow-up of 24.5 years, 24 (23%) patients died (14 MEN1-related and 10 non-MEN1-related deaths). Comparing the causes of death with the results from the 227 patients in the pooled literature series, we found that no patients died of acute complications due to acid hypersecretion, and 8%-14% died of other hormone excess causes, which is similar to the results in 10 large MEN1 literature series published since 1995. In the 2 series (the NIH and pooled literature series), two-thirds of patients died from an MEN1-related cause and one-third from a non-MEN1-related cause, which agrees with the mean values reported in 10 large MEN1 series in the literature, although in the literature the causes of death varied widely. In the NIH and pooled literature series, the main causes of MEN1-related deaths were due to the malignant nature of the PETs, followed by the malignant nature of thymic carcinoid tumors. These results differ from the results of a number of the literature series, especially those reported before the 1990s. The causes of non-MEN1-related death for the 2 series, in decreasing frequency, were cardiovascular disease, other nonendocrine tumors > lung diseases, cerebrovascular diseases. The most frequent non-MEN1-related tumor deaths were colorectal, renal > lung > breast, oropharyngeal. Although both overall and disease-related survival are better than in the past (30-yr survival of NIH series: 82% overall, 88% disease-related), the mean age at death was 55 years, which is younger than expected for the general population.Detailed analysis of causes of death correlated with clinical, laboratory, and tumor characteristics of patients in the 2 series allowed identification of a number of prognostic factors. Poor prognostic factors included higher fasting gastrin levels, presence of other functional hormonal syndromes, need for >3 parathyroidectomies, presence of liver metastases or distant metastases, aggressive PET growth, large PETs, or the development of new lesions.The results of this study have helped define the causes of death of MEN1 patients at present, and have enabled us to identify a number of prognostic factors that should be helpful in tailoring treatment for these patients for both short- and long-term management, as well as in directing research efforts to better define the natural history of the disease and the most important factors determining long-term survival at present.

Value of surgery in patients with negative imaging and sporadic Zollinger-Ellison syndrome

OBJECTIVES

To address the value of surgery in patients with sporadic Zollinger-Ellison syndrome (ZES) with negative imaging studies.

BACKGROUND

Medical control of acid hypersecretion in patients with sporadic ZES is highly effective. This has led to these patients frequently not being sent to surgery, especially if preoperative imaging studies are negative, due, in large part, to existence of almost no data on the success of surgery in this group.

METHODS

Fifty-eight prospectively studied patients with sporadic ZES (17% of total studied) had negative imaging studies, and their surgical outcome was compared with 117 patients with positive imaging results.

RESULTS

Thirty-five patients had negative imaging studies in the pre-somatostatin receptor scintigraphy (SRS) era, and 23 patients in the post-SRS era. Patients with negative imaging studies had long disease histories before surgery [mean ± SEM (from onset) = 7.9 ± 1 [range, -0.25 to 35 years]) and 25% were followed for 2 or more years from diagnosis. At surgery, gastrinoma was found in 57 of 58 patients (98%). Tumors were small (mean = 0.8 cm, 60% <1 cm). The most common primary sites were duodenal 64%, pancreatic 17%, and lymph node (10%). Fifty percent had a primary-only, 41% primary + lymph node, and 7% had liver metastases. Thirty-five of 58 patients (60%) were cured immediately postoperatively, and at last follow-up [mean = -9.4 years; range, 0.2-22 years], 27 patients (46%) remained cured. During follow-up, 3 patients died, each had liver metastases at surgery. In comparison to positive imaging patients, those with negative imaging studies had lower preoperative fasting gastrin levels; had a longer delay before surgery; more frequently had a small duodenal tumor; less frequently had a pancreatic tumor, multiple tumors, or developed a new lesion postoperatively; and had a longer survival.

CONCLUSIONS

Sporadic ZES patients with negative imaging studies are not rare even in the post-SRS period. An experienced surgeon can find gastrinoma in almost every patient (98%) and nearly one half (46%) are cured, a rate similar to patients with positive imaging findings. Because liver metastases were found in 7%, which may have been caused by a long delay in surgery and all the disease-related deaths occurred in this group, surgery should be routinely undertaken early in ZES patients despite negative imaging studies.

Diagnosis and Treatment of Gastrinomas in Multiple Endocrine Neoplasia Type 1 (MEN-1)

Multiple endocrine neoplasia type 1 (MEN-1) is a rare autosomal-dominant disease. It is associated with a broad range of endocrine tumours, most frequently arising in the parathyroid glands, the pituitary and the pancreas. Most neuroendocrine tumours will be diagnosed in the pancreas as non-functioning neuroendocrine tumours or insulinomas. Forty-two percent of the patients will develop a gastrin-secreting neuroendocrine tumour, a gastrinoma. Gastrinomas in MEN-1 tend to be small, multiple and preferentially located in the duodenum. This paper will focus on the specific characteristics of gastrinomas in the setting of MEN-1 compared to sporadic gastrinomas. The developments in understanding the tumorigenesis of these tumours and the consequences for diagnosis and therapy will be discussed.

Inherited pancreatic endocrine tumor syndromes: advances in molecular pathogenesis, diagnosis, management, and controversies

Pancreatic endocrine tumors (PETs) can occur as part of 4 inherited disorders, including Multiple Endocrine Neoplasia type 1 (MEN1), von Hippel-Lindau disease (VHL), neurofibromatosis 1 (NF-1) (von Recklinghausen disease), and the tuberous sclerosis complex (TSC). The relative frequency with which patients who have these disorders develop PETs is MEN1>VHL>NF-1>TSC. Over the last few years, there have been major advances in the understanding of the genetics and molecular pathogenesis of these disorders as well in the localization and the medical and surgical treatment of PETs in such patients. The study of PETs in these disorders not only has provided insights into the possible pathogenesis of sporadic PETs but also has presented several unique management and treatment issues, some of which are applicable to patients with sporadic PETs. Therefore, the study of PETs in these uncommon disorders has provided valuable insights that, in many cases, are applicable to the general group of patients with sporadic PETs. In this article, these areas are reviewed briefly along with the current state of knowledge of the PETs in these disorders, and the controversies that exist in their management are summarized briefly and discussed.

Serum gastrin in Zollinger-Ellison syndrome: II. Prospective study of gastrin provocative testing in 293 patients from the National Institutes of Health and comparison with 537 cases from the literature. evaluation of diagnostic criteria, proposal of new criteria, and correlations with clinical and tumoral features

In two-thirds of patients with Zollinger-Ellison syndrome (ZES), fasting serum gastrin (FSG) levels overlap with values seen in other conditions. In these patients, gastrin provocative tests are needed to establish the diagnosis of ZES. Whereas numerous gastrin provocative tests have been proposed, only the secretin, calcium, and meal tests are widely used today. Many studies have analyzed gastrin provocative test results in ZES, but they are limited by small patient numbers and methodologic differences. To address this issue, we report the results of a prospective National Institutes of Health (NIH) study of gastrin provocative tests in 293 patients with ZES and compare these data with those from 537 ZES and 462 non-ZES patients from the literature. In 97%-99% of gastrinoma patients, an increase in serum gastrin post secretin (Delta secretin) or post calcium (Delta calcium) occurred. In NIH ZES patients with <10-fold increase in FSG, the sensitivity/specificity of the widely used criteria were as follows: Delta secretin > or =200 pg/mL (83%/100%), Delta secretin >50% (86%/93%), Delta calcium > or =395 pg/mL (54%/100%), and Delta calcium >50% (78%/83%). A systematic analysis of the sensitivity and specificity of other possible criteria for a positive secretin or calcium test allowed us to identify a new criterion for secretin testing (Delta > or =120 pg/mL) with the highest sensitivity/specificity (94%/100%) and to confirm the commonly used criterion for calcium tests (Delta > or =395 pg/mL) (62%/100%). This analysis further showed that the secretin test was more sensitive than the calcium test (94% vs. 62%). Our results suggest that secretin stimulation should be used as the first-line provocative test because of its greater sensitivity and simplicity and lack of side effects. In ZES patients with a negative secretin test, 38%-50% have a positive calcium test. Therefore the calcium test should be considered in patients with a strong clinical suspicion of ZES but a negative secretin test. Furthermore, we found that some clinical (diarrhea, duration of medical treatment), laboratory (basal acid output), and tumoral (size, extent) characteristics correlate with the serum gastrin increase post secretin and post calcium. However, using the proposed criteria, the result of these provocative tests (that is, positive or negative) is minimally influenced by these factors, so secretin and calcium provocative tests are reliable in patients with different clinical, laboratory, and tumor characteristics. A systematic analysis of meal testing showed that 54%-77% of ZES patients have a <50% postprandial serum gastrin increase. However, 9%-20% of ZES patients had a >100% increase post meal, causing significant overlap with antral syndromes. Furthermore, we could not confirm the usefulness of meal tests for localization of duodenal gastrinomas. We conclude that the secretin test is a crucial element in the diagnosis of most ZES patients, the calcium test may be useful in selected patients, but the meal test is not helpful in the management of ZES. For secretin testing, the criterion with the highest sensitivity and specificity is an increase of > or =120 pg/mL, which should replace other criteria commonly used today.

Serum gastrin in Zollinger-Ellison syndrome: I. Prospective study of fasting serum gastrin in 309 patients from the National Institutes of Health and comparison with 2229 cases from the literature

The assessment of fasting serum gastrin (FSG) is essential for the diagnosis and management of patients with the Zollinger-Ellison syndrome (ZES). Although many studies have analyzed FSG levels in patients with gastrinoma, limited information has resulted from these studies because of their small size, different methodologies, and lack of correlations of FSG levels with clinical, laboratory, or tumor features in ZES patients. To address this issue, we report the results of a prospective National Institutes of Health (NIH) study of 309 patients with ZES and compare our results with those of 2229 ZES patients in 513 small series and case reports in the literature. In the NIH and literature ZES patients, normal FSG values were uncommon (0.3%-3%), as were very high FSG levels >100-fold normal (4.9%-9%). Two-thirds of gastrinoma patients had FSG values <10-fold normal that overlap with gastrin levels seen in more common conditions, like Helicobacter pylori infection or antral G-cell hyperplasia/hyperfunction. In these patients, FSG levels are not diagnostic of ZES, and gastrin provocative tests are needed to establish the diagnosis. Most clinical variables (multiple endocrine neoplasia type 1 status, presence or absence of the most common symptoms, prior medical treatment) are not correlated with FSG levels, while a good correlation of FSG values was found with other clinical features (prior gastric surgery, diarrhea, duration from onset to diagnosis). Increasing basal acid output, but not maximal acid output correlated closely with increasing FSG. Numerous tumoral features correlated with the magnitude of FSG in our study, including tumor location (pancreatic > duodenal), primary size (larger > smaller) and extent (liver metastases > local disease). In conclusion, this detailed analysis of FSG in a large number of patients with ZES allowed us to identify important clinical guidelines that should contribute to improved diagnosis and management of patients with ZES.

Pancreatectomy in multiple endocrine neoplasia type 1-related gastrinomas and pancreatic endocrine neoplasias

OBJECTIVE

The aim of this study was to evaluate the results of pancreatic resection in pancreatic endocrine neoplasias (PENs) in patients affected by multiple endocrine neoplasia type 1 (MEN1) syndrome.

BACKGROUND

Since these tumors often show an indolent course, the role of diagnostic procedures and type of surgical approach are controversial. Experience with new diagnostic approaches and more aggressive surgery is still limited.

METHODS

Sixteen MEN1 patients were referred to our Surgical Unit (1992-2003) and were operated on for the indications of hypergastrinism, hypoglycemia, and/or pancreatic endocrine neoplasias larger than 1 cm. Zollinger-Ellison syndrome (ZES) was present in 13 patients, 2 of whom experienced a recurrence after previous surgery. Preoperative tumor localization was carried out using ultrasonography (US), computed tomography (CT), endoscopic ultrasonography (EUS), somatostatin receptor scintigraphy (SSRS), or selective arterial secretin injection (SASI). Rapid intraoperative gastrin measurement (IGM) was carried out in 8 patients, and 1 patient also underwent an intraoperative secretin provocative test.

RESULTS

Either pancreatoduodenectomy (PD) or total pancreatectomy (TP) or distal pancreatectomy was performed. There was no postoperative mortality; 37% complications included pancreatic (27%) and biliary (6%) fistulas, abdominal collection (6%), and acute pancreatitis (6%). EUS and SSRS were the most sensitive preoperative imaging techniques. At follow-up, 10 of 13 hypergastrinemic patients (77%) are currently eugastrinemic with negative secretin provocative test, while 3 are showing a recurrence of the disease. All patients affected by insulinoma were cured.

CONCLUSIONS

MEN1 tumors should be considered surgically curable diseases. IGM may be of value in the assessment of surgical cure. Our experience suggests that PD is superior to less radical surgical approaches in providing cure with limited morbidity in MEN1 gastrinomas and pancreatic neoplasias.

Surgery and prognosis of duodenal gastrinoma as a duodenal neuroendocrine tumor

It has become increasingly clear that duodenal gastrinomas are the most common cause of Zollinger-Ellison syndrome (ZES). However, attempts to find these tumors before and during surgery for ZES have had limited success until duodenotomy (opening the duodenum) was described. The routine use of duodenotomy in patients with non-familial gastrinoma increases the number of duodenal tumors found, and the immediate and long-term cure-rate. The increase in cure-rate appears to be secondary to increased detection of small, previously undetectable duodenal gastrinomas. Duodenotomy detects small tumors (<1 cm) in the proximal duodenum. It does not detect more duodenal gastrinomas per patient, nor does it detect tumors in unusual duodenal locations. Duodenotomy decreases the death-rate associated with these tumors. However, it has not affected the rate of development of liver metastases. Duodenotomy is a critical method to find duodenal gastrinomas. It should be routinely performed in all surgery to find and remove gastrinoma for cure of ZES.

Surgical treatment and prognosis of gastrinoma

Zollinger-Ellison syndrome (ZES) is a clinical syndrome with severe peptic ulcer disease and diarrhea caused by gastric acid hypersecretion secondary to a neuroendocrine tumour that secretes excessive amounts of the hormone gastrin (gastrinoma). Gastrinomas occur in a familial and a sporadic form. Patients with gastrinoma in the familial setting of Multiple Endocrine Neoplasia type 1 (MEN-1) are seldom, if ever, cured of Zollinger-Ellison syndrome by the current non-Whipple operations to remove duodenal and pancreatic gastrinoma. Surgery is currently used in these patients to deal with the malignant nature of pancreatic or duodenal neuroendocrine tumours. Malignant potential is best determined by tumour size. Tumours that are greater than 2 cm in size should be excised. In the sporadic setting, cure occurs in a significant proportion of patients (50%) by surgical resection of gastrinoma. Duodenotomy has improved both the tumour detection rate and the cure rate and should be routinely done. Whipple pancreaticoduodenectomy results in the highest probability of cure in both sporadic and MEN-1 gastrinoma patients as it removes the entire gastrinoma triangle. However, the excellent long-term survival of these patients with lesser operations and the increased operative mortality and long-term morbidity of Whipple make its current role unclear until further studies are done.

Advances in evaluation and management of gastrinoma in patients with Zollinger-Ellison syndrome

Gastrinomas producing Zollinger-Ellison syndrome are the most frequent symptomatic, malignant pancreatic endocrine tumor syndrome. Recently, a number of important studies have examined their molecular pathogenesis and natural history and provided important guidelines for their treatment. Each of these areas is briefly reviewed in this article.

Resolved and unresolved controversies in the surgical management of patients with Zollinger-Ellison syndrome

OBJECTIVE

Highlight unresolved controversies in the management of Zollinger-Ellison syndrome (ZES).

SUMMARY BACKGROUND DATA

Recent studies have resolved some of the previous controversies including the surgical cure rate in patients with and without Multiple Endocrine Neoplasia-type1 (MEN1), the biological behavior of duodenal and pancreatic gastrinomas, role of imaging studies to localize tumor, and gastrectomy to manage acid output.

METHODS

Review of the literature based on computer searches in Index Medicus, Pubmed and Ovid.

RESULTS

Current controversies as identified in the literature include the role of endoscopic ultrasound (EUS), surgery in ZES patients with MEN1, pancreaticoduodenectomy (Whipple procedure), lymph node primary gastrinoma, parietal cell vagotomy, reoperation and surgery for metastatic tumor, and the use of minimally invasive surgical techniques to localize and remove gastrinoma.

CONCLUSIONS

It is hoped that future studies will focus on these issues to improve the surgical management of ZES patients.

Does the use of routine duodenotomy (DUODX) affect rate of cure, development of liver metastases, or survival in patients with Zollinger-Ellison syndrome?

OBJECTIVE

To determine whether routine use of duodenotomy (DUODX) alters cure rate, survival, or development of liver metastases in 143 patients (162 operations) with Zollinger-Ellison syndrome (ZES) without MEN1.

SUMMARY BACKGROUND DATA

DUODX has been shown to increase the detection of duodenal gastrinomas, but it is unknown if it alters rate of cure, liver metastases, or survival. Data from our prospective studies of surgery in ZES allow us to address this issue because DUODX was not performed before 1987, whereas it was routinely done after 1987.

METHODS

All patients with sporadic ZES (non-MEN1) undergoing surgery for possible cure without a prior DUODX from November 1980 to June 2003 were included. Patients had preoperative computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound; if unclear, angiography and somatostatin receptor scintigraphy since 1994. At surgery, all had the same standard ZES operation and were assessed immediately postoperatively, at 3 to 6 months, and yearly for cure (fasting gastrin, secretin test. and imaging studies).

RESULTS

A DUODX was performed in 79 patients (94 operations), and no DUODX was performed in 64 patients (68 operations), with 10 patients having both (no DUODX, then a DUODX later). Gastrinoma was found in 98% with DUODX compared with 76% with no DUODX (P < 0.00001). Duodenal gastrinomas were found more frequently with DUODX (62% vs. 18%; P < 0.00001), whereas pancreatic, lymph node, and other primary gastrinomas occurred similarly. Six of the 10 patients with 2 operations had a duodenal tumor found with DUODX during a second operation that was missed in the first operation without DUODX. Both the immediate postoperative cure rate (65% vs. 44%; P = 0.010) and long-term cure rate at last follow-up (8.8 +/- 0.4 years; range, 0.1 to 21.5) (52% vs. 26%; P = 0.0012) were significantly greater with a DUODX than without. In patients without pancreatic tumors or liver metastases at surgery, both the rate of developing liver metastases (6% vs. 9.5%) and the disease-related death rate (0% vs. 2%) were low and not significantly different in patients with or without a DUODX.

CONCLUSIONS

These results demonstrate that routine use of DUODX increases the short-term and long-term cure rate due to the detection of more duodenal gastrinomas. The rate of development of hepatic metastases and/or disease-related mortality in patients without pancreatic tumors is low, and no effect of DUODX on these parameters was seen. Duodenotomy (DUODX) should be routinely performed during all operations for cure of sporadic ZES.

Diagnostic uses of radiolabelled somatostatin receptor analogues in gastroenteropancreatic endocrine tumours

Numerous studies have established that gastroenteropancreatic endocrine tumours (carcinoids and pancreatic endocrine tumours) resemble a number of other tumours in overexpressing somatostatin receptors that can bind octreotide or lanreotide with high affinity (i.e. possess sst2/sst5 receptors). Recent studies report that radiolabelled somatostatin analogues can be used to image these tumours (somatostatin receptor scintigraphy) and may be useful for peptide-directed radionuclide therapy. In this paper the evidence is reviewed that has led to establishing somatostatin receptor scintigraphy as the initial imaging modality of choice in patients with gastroenteropancreatic tumours. This conclusion is based on an understanding of the results with conventional imaging modalities (ultrasound, computed tomographic scan, magnetic resonance imaging, angiography) available prior to somatostatin receptor scintigraphy and the results of studies demonstrating the sensitivity and specificity of somatostatin receptor scintigraphy. Most important in this regard are the results of studies that have assessed the use of somatostatin receptor scintigraphy on clinical management. Each of these areas is reviewed in this paper.

Multiple endocrine neoplasia type 1 and Zollinger-Ellison syndrome: a prospective study of 107 cases and comparison with 1009 cases from the literature

In patients with multiple endocrine neoplasia type 1 (MEN1), the most common functional pancreatic endocrine tumor (PET) syndrome is Zollinger-Ellison syndrome (ZES). ZES has been well studied in its sporadic form (that is, without MEN1); however, there are limited data on patients with MEN1 and ZES (MEN1/ZES), and the long-term natural history is largely unknown. To address this issue we report the results of a prospective long-term National Institutes of Health (NIH) study of 107 MEN1/ZES patients and compare our results with those of 1009 MEN1/ZES patients in 278 case reports and small series in the literature. Patients were clinically, radiologically, and biochemically evaluated yearly for all MEN1 manifestations (mean follow-up, 10 yr; range, 0.1-31 yr). Compared with patients from the literature, the NIH MEN1/ZES patients more frequently had pituitary (60%) and adrenal (45%) disease and carcinoid tumors (30%), but had equal frequency of hyperparathyroidism (94%), thyroid disease (6%), or lipomas (5%). Twenty-five percent of both the NIH and the literature patients lacked a family history of MEN1; ZES was the initial clinical manifestation of MEN1 in 40%. ZES onset preceded the diagnosis of hyperparathyroidism in 45%. However, ZES was rarely (8%) the only initial manifestation of MEN1 if careful testing was done. ZES occurred before age 40 years in 50%-60% of the current patients, in contrast to older studies. The diagnosis of ZES is delayed 3-5 years from its onset and is delayed as long as in sporadic ZES cases. Pituitary disease and carcinoid tumors (gastric > bronchial, thymic) are more frequent than generally reported, whereas a second functional PET is uncommon. In patients with MEN1/ZES without a family history of MEN1, the MEN1 manifestations are not as severe. This study shows that MEN1/ZES patients differ in many aspects from those commonly reported in older studies involving few MEN1/ZES patients. In this study we have identified a number of important clinical and laboratory features of MEN1/ZES that were not previously appreciated, which should contribute to earlier diagnosis and improve both short- and long-term management.

Neuroendocrine tumours: clinical presentation and management of localized disease

Neuroendocrine tumours often present a diagnostic and therapeutic challenge. They can arise almost anywhere in the body, and are therefore associated with a broad range of local symptoms. The systemic manifestations of neuroendocrine tumours are also diverse, and are related to the secretion of numerous hormones and biogenic amines. In recent years, improved diagnostic techniques, increased recognition of neuroendocrine tumour subtypes, and new therapeutic modalities have enhanced clinicians' ability to detect and appropriately treat these malignancies.

Current surgical management of Zollinger-Ellison syndrome (ZES) in patients without multiple endocrine neoplasia-type 1 (MEN1)

The role of surgery in the management of patients with sporadic (not part of multiple endocrine neoplasia type 1) Zollinger-Ellison syndrome (ZES) is controversial. In this setting, 60-90% of gastrinomas are malignant and medical therapy can control the gastric acid hypersecretion in virtually every patient. Therefore, the progression of tumor is the major determinant of survival. Surgery will cure approximately one-third of patients with sporadic ZES. It will decrease the development of liver metastases and may improve survival. Somatostatin receptor scintigraphy is the best preoperative localization study. Its results are as good as all other imaging studies combined. Operative techniques should always include duodenotomy (opening the duodenum) and meticulous dissection of lymph nodes in the gastrinoma triangle, because duodenal primary tumors are often missed and lymph node primary tumors or metastases are common. Postoperative evaluation should include secretin test because it is the most sensitive method to document cure and detect tumor recurrence.

Management and outcome of patients with sporadic gastrinoma arising in the duodenum

BACKGROUND

Primary duodenal gastrinomas are now recognized as a common etiology for patients with sporadic Zollinger Ellison Syndrome (ZES); however, the clinical and pathologic features of this condition and long-term outcome after operation are not well characterized.

METHODS

Between November 1982 and September 2000, 63 patients diagnosed with sporadic ZES underwent resection of a primary duodenal gastrinoma and regional nodal metastases with curative intent. Data from a prospectively maintained database were reviewed for clinical and pathologic parameters relating to primary tumor size, location, frequency of lymph node metastases, and disease-specific and disease-free survival.

RESULTS

There were 41 males and 22 females (mean age, 48.6 years). The majority of duodenal gastrinomas were in the first or second portions of the duodenum (83%). Tumor size ranged from 0.2 to 2.0 cm with 62% measuring less than 1.0 cm. Sixty percent of individuals had regional lymph node metastases identified primarily in proximity to the primary tumor. At a median 10-year follow-up, the overall disease-specific and disease-free survivals were 100% and 60%, respectively. Actuarial 10-year disease-free survival was significantly higher for patients without lymph node metastases versus those with lymph node metastases (78% versus 48%, P = 0.0137).

CONCLUSIONS

Duodenal gastrinomas in patients with sporadic ZES are frequently small, most commonly located in the proximal duodenum, and associated with regional lymph node metastases in 60%. Disease-free survival is lower for patients with regional lymph node metastases suggesting that a more systematic lymphadenectomy to extirpate occult disease may be indicated in this group.

The surgical management of pancreatic neuroendocrine tumors

NETs of pancreas are rare and may or may not be associated with symptoms of hormone overproduction. Treatment is required for control of tumor growth and for relief of symptoms associated with excess hormone. With advances in the nonsurgical management of many hormone-related symptoms (e.g., proton pump inhibitors or somatostatin analogues), care for many of these patients has shifted toward the control of tumor progression. Complete surgical resection is the only curative treatment for these tumors. With improvements in the preoperative imaging and intraoperative localization techniques, it is hoped that these tumors will be identified and resected for cure with increased frequency. For patients with hepatic metastasis, initial expectant observation and medical management of symptoms is appropriate in view of the long and indolent course of the disease. Hepatic arterial embolization is the preferred mode of palliation for pain and hormonal symptoms. A curative hepatic resection may be possible in selected patients.

A personal experience with pancreatic and duodenal neuroendocrine tumors

BACKGROUND

Since the concept of hormones was proposed in 1901, numerous gastrointestinal hormones and neuroendocrine tumors that can produce these hormones have been identified. The most common tumors are gastrinomas and insulinomas.

STUDY DESIGN

During a 35-year experience, there were 82 neuroendocrine tumors, including 37 gastrinomas, 11 insulinomas, 16 nonfunctioning tumors, 11 gastrinomas suspected but not found, 3 tumors arising in lymph nodes, 1 somatostatinoma, 1 glucagonoma, and 2 amphicrine tumors. MEN I syndrome coexisted with three pancreatic gastrinomas, two pancreatic and duodenal gastrinomas, four suspected gastrinomas, one nonfunctioning tumor, two insulinomas, and no duodenal gastrinomas.

RESULTS

Of the nine patients with pancreatic gastrinoma without MEN I, three had lymph node, three had liver metastases, and one had both. The mean survival time was 4.8 years. Three patients with pancreatic gastrinoma and MEN I were alive at 2, 17, and 20 years, respectively. Of the 20 patients with duodenal gastrinoma, none had MEN I; 13 had lymph node metastases and 1 had liver metastases. The overall followup was 7.0 years. Ten patients were biochemically cured. Nonfunctioning tumors, with one exception, originated in the pancreas. Of the three gastrinomas potentially arising in lymph nodes, two, and possibly three, were cured by node removal. Eleven patients had an insulinoma. No patient had recurrence of hypoglycemia after removal of an insulinoma.

CONCLUSIONS

Patients with duodenal gastrinoma with lymph node metastases were curable, and cures were achieved occasionally after resection of liver metastases. Results of operation were similar for those with and without MEN I. MEN I and metastases were not contraindications to operation; instead, these patients should be operated on aggressively. Gastrinomas not found at operation were likely to be small duodenal gastrinomas. Gastrinomas can arise in a lymph node and can be cured by its removal. Parietal cell vagotomy is recommended after operation for gastrinomas in the event of residual tumor. With the exception of patients with MEN I or microadenomata, insulinomas were treated best by tumor enucleation. Otherwise, Whipple operation or distal pancreatectomy and enucleation of tumor in the remaining pancreas was indicated.

Current perspectives in the surgery of multiple endocrine neoplasias

Multiple endocrine neoplasia is an uncommon but fascinating condition. In this review we examine the multifaceted presentations, the diagnostic challenges and different management strategies for various syndromes. This is an attempt to share our knowledge and experience towards achieving better outcomes in the management of the diseases.

Prognostic factors in patients with Zollinger-Ellison syndrome and multiple endocrine neoplasia type 1. Groupe d'Etude des Néoplasies Endocriniennes Multiples (GENEM and groupe de Recherche et d'Etude du Syndrome de Zollinger-Ellison (GRESZE)

BACKGROUND & AIMS

Risk factors of metachronous liver metastases and death are not well known in patients with the Zollinger-Ellison syndrome and multiple endocrine neoplasia type 1. These factors were retrospectively determined in 77 patients.

METHODS

Data chart review was performed.

RESULTS

Median follow-up was 102 months (range, 12-366). Surgery was performed on 48 patients, including 9 of the 10 patients with large pancreatic tumors (>/=3 cm). Liver metastases developed in 4 patients (40%) with large pancreatic tumors, in 3 (4.8%) without, and in 1 of the 4 patients with pancreatic tumors of unknown size; all had previously undergone surgery. The only independent factor associated with development of liver metastases identified by multivariate analysis was large pancreatic tumors (risk ratio, 29.0; 95% confidence interval [CI], 3. 2-260.7). Surgery was not selected. The probability of being free of liver metastases in the 63 patients without large pancreatic tumors was 96% (95% CI, 88-100) at 10 and 15 years. Thirteen (16.9%) patients died. The only independent factors of death selected by multivariate analysis were Zollinger-Ellison syndrome diagnosis before 1980 (risk ratio, 8.2; 95% CI, 1.7-40.6) and age at diagnosis (risk ratio/year, 1.08; 95% CI, 1.03-1.14).

CONCLUSIONS

Large pancreatic tumors are predictive of the development of metachronous liver metastases, and surgery does not seem to prevent them.

Analysis of factors associated with long-term (five or more years) cure in patients undergoing operation for Zollinger-Ellison syndrome

BACKGROUND

Only 30% to 40% of patients with Zollinger-Ellison syndrome (ZES) undergoing operation with curative intent have biochemical cures. The purpose of this analysis was to identify perioperative factors associated with long-term (> or = 5 years) biochemical cures.

METHODS

From December 1981 to September 1997, 128 patients with potentially curable ZES underwent 152 abdominal explorations with resection of all identifiable disease. Of these, 31 outcomes were identified with documented cures at > or = 5 years from operation and were compared with outcomes of 110 patients who were not cured. Univariate and multivariate statistical analyses were performed.

RESULTS

The results of a normal immediate postoperative fasting serum gastrin and secretin stimulation test were significantly and independently correlated with 5-year cure (P2 = .005 and .0099, respectively). A diagnosis of multiple endocrine neoplasia type 1 was significantly inversely correlated with cure on univariate analysis (P2 = .027). Gender, age, duration of symptoms, results of diagnostic tests, or results of imaging studies did not correlate with outcome.

CONCLUSIONS

All patients with sporadic potentially curable ZES should undergo exploration because outcome is not associated with preoperative tests. Only 5% of patients with ZES and multiple endocrine neoplasia type 1 were cured at 5 years. A normal fasting serum gastrin or secretin stimulation value value immediately postoperatively provides important prognostic information.

Prospective study of somatostatin receptor scintigraphy and its effect on operative outcome in patients with Zollinger-Ellison syndrome

OBJECTIVE

To determine the relative abilities of somatostatin receptor scintigraphy (SRS) and conventional imaging studies (computed tomography, magnetic resonance imaging, ultrasound, angiography) to localize gastrinomas before surgery in patients with Zollinger-Ellison syndrome (ZES) subsequently found at surgery, and to determine the effect of SRS on the disease-free rate.

SUMMARY BACKGROUND DATA

Recent studies demonstrate that SRS is the most sensitive imaging modality for localizing neuroendocrine tumors such as gastrinomas. Because of conflicting results in small series, it is unclear in ZES whether SRS will alter the disease-free rate, which gastrinomas are not detected, what factors contribute to failure to detect a gastrinoma, or whether the SRS result should be used to determine operability in patients without hepatic metastases, as recently recommended by some investigators.

METHODS

Thirty-five consecutive patients with ZES undergoing 37 exploratory laparotomies for possible cure were prospectively studied. All had SRS and conventional imaging studies before surgery. Imaging results were determined by an independent investigator depending on surgical findings. All patients underwent an identical surgical protocol (palpation after an extensive Kocher maneuver, ultrasound during surgery, duodenal transillumination, and 3 cm duodenotomy) and postoperative assessment of disease status (fasting gastrin, secretin test imaging within 2 weeks, at 3 to 6 months, and yearly), as used in pre-SRS studies previously.

RESULTS

Gastrinomas were detected in all patients at each surgery. Seventy-four gastrinomas were found: 22 duodenal, 8 pancreatic, 3 primaries in other sites, and 41 lymph node metastases. The relative detection order on a per-patient or per-lesion basis was SRS > angiography, magnetic resonance imaging, computed tomography > ultrasound. On a per-lesion basis, SRS had greater sensitivity than all conventional studies combined. SRS missed one third of all lesions found at surgery. SRS detected 30% of gastrinomas < or =1.1 cm, 64% of those 1.1 to 2 cm, and 96% of those >2 cm and missed primarily small duodenal tumors. Tumor size correlated closely with SRS rate of detection. SRS did not increase the disease-free rate immediately after surgery or at 2 years mean follow-up.

CONCLUSIONS

SRS is the most sensitive preoperative imaging study for extrahepatic gastrinomas in patients with ZES and should replace conventional imaging studies as the preoperative study of choice. Negative results of SRS for localizing extrahepatic gastrinomas should not be used to decide operability, because a surgical procedure will detect 33% more gastrinomas than SRS. SRS does not increase the disease-free rate. In the future, more sensitive methods to detect small gastrinomas, especially in the duodenum and in periduodenal lymph nodes, or more extensive surgery will be needed to improve the postoperative disease-free rate in ZES.

Management of the Zollinger-Ellison syndrome in patients with multiple endocrine neoplasia type 1

Zollinger-Ellison syndrome (ZES) is the most common symptomatic pancreatic endocrine tumour in patients with MEN-1. Besides the treatment of the usual endocrinopathies seen in patients with MEN-1, the treatment of the ZES requires attention be paid to controlling the gastric acid hypersecretion, to dealing with the gastrinomas per se which are malignant in 18-60% of cases, and to the diagnosis and treatment of gastric carcinoid tumours, that are increasingly seen in these patients. In this article the current management of each of the areas is reviewed and what is known or uncertain discussed, based on our studies at the NIH and data from others. Data from 231 patients including 45 with MEN-1 and 186 without MEN-1 is contrasted in this report. Gastric acid hypersecretion has been controlled in all patients medically with MEN-1 and ZES at the NIH for up to 22 years. The current drugs of choice are H+-K+ ATPase inhibitors and twice a day dosing is recommended. Periods of parenteral drug therapy (surgery, etc.) and pregnancy require important modifications. The appropriate surgical therapy of the gastrinoma is controversial. Eighty per cent of patients have a duodenal gastrinoma and 20-30% have a pancreatic tumour. Recent studies suggest gastrinoma enucleation combined with duodenotomy rarely results in cure. Aggressive surgery (Whipple resection) can result in cure of gastrinoma but effect on survival is unclear. There are important differences in gastrinoma location, extent, and percentage with aggressive disease in patients with or without MEN-1, which are discussed. Confusion has occurred because of lack of information on the natural history of the gastrinoma compared to the other pancreatic endocrine tumours that occur in MEN-1 and survival data from patients with and without MEN-1 is contrasted. The occurrence of gastric carcinoids in patients with and without MEN-1 with ZES is contrasted and the areas of certainty and disagreement reviewed.

Gastrinoma: State of the Art

BACKGROUND: The Zollinger-Ellison syndrome, implicating a gastrinoma, was first recognized as a disease entity in 1955. At that time, total gastrectomy was the most common treatment approach. Advances in several aspects of the disease have occurred since that time. METHODS: The authors reviewed the changes that have developed since 1955 in the diagnosis, imaging studies, operative and nonoperative management, and follow-up of patients with this disease. RESULTS: The presence of a gastrinoma can be confirmed by a secretin stimulation test. A variable number of patients have hyperparathyroidism as part of the multiple endocrine neoplasm syndrome type 1 (MEN 1). Localization of the primary gastrinoma has been assisted by selective angiography, endoscopic ultrasonography, and the octreotide scan. H2-blockers or omeprazole, sometimes at high doses, usually controls acid secretion. Surgical removal of the primary gastrinoma is performed when feasible, and parathyroidectomy is indicated in those patients with hyperparathyroidism in the MEN 1 syndrome. Follow-up is facilitated by measurement of fasting serum gastrin levels. CONCLUSIONS: Several innovations have improved our capability to diagnose and effectively manage patients with gastrinoma.

Gastrointestinal endocrine tumours. Gastrinoma

Since the description of the Zollinger-Ellison syndrome in two patients in 1955, there have been significant advances in the understanding of its pathogenesis, natural history, relationship to multiple endocrine neoplasia type 1, diagnosis, methods of tumour localization and management. The main focus in treatment is now shifting from management of the gastric acid hypersecretory state which can now be controlled medically in almost every patient, to the management of the gastrinoma. Recent studies are beginning to provide insights into the natural history of gastrinomas, factors that are associated with invasiveness in some gastrinomas, defining the role of surgery in managing patients with different disease extents, or with MEN 1 and being able to provide insights into molecular abnormalities that may be important in their pathogenesis. In this article each of these advances is briefly reviewed with emphasis primarily on recent advances.

Neuroendocrine gastrointestinal tumours

Neuroendocrine gut and pancreatic tumours have provided a diagnostic and therapeutic challenge over the years. These rather slowly growing neoplasms have been assigned a good prognosis but when liver metastases are present the prognosis is not better than that of most other malignant tumours. Despite the development of improved diagnostic procedures many patients are still referred at a stage of the disease too late for surgical cure, at which time medical treatment is warranted. The diagnosis is based on histopathological diagnosis including silver stainings (Grimelius, Masson) and immunohistochemistry for chromogranin A and synaptophysin. Analysis of chromogranin A in the plasma is an important adjunct in the screening for various types of neuroendocrine gut and pancreatic tumours. About 80%-100% of patients with verified neuroendocrine gastrointestinal tumours have elevated circulating levels of this glycoprotein. Depending on clinical symptoms the chromogranin A analysis is supplemented by other peptide hormone analyses as well as urinary 5-HIAA for patients with midgut carcinoid tumours. In the past the localization procedures were based on CT, MRI and ultrasound investigations but in recent years somatostatin receptor scintigraphy (octreoscan) and endoscopic ultrasonography have significantly improved the diagnostic potential. Almost 80% of neuroendocrine gastrointestinal tumours present somatostatin receptor subtype 2 binding 111Indium-labelled octreotide which can be used for staging of the disease, and which also indicates whether or not somatostatin analogues can be used in the treatment of these tumours. Surgery is still a cornerstone in the treatment of neuroendocrine gastrointestinal tumours, even if the patients are beyond cure. Debulking procedures and bypassing operations are important for improving clinical condition and facilitating impending medical treatment, and during the past decade a more aggressive surgical approach has emerged. The medical treatment is based on chemotherapy, and the use of somatostatin analogues and alpha-interferons. Chemotherapy, in particular the combination of streptozotocin with 5-FU or doxorubicin, is still first-line treatment for most endocrine pancreatic tumours, while somatostatin analogues and alpha-interferons are considered first-line for classical midgut carcinoids. Chemotherapy and biotherapy can be combined in many patients, and changes from one medical treatment to another during the course of the disease is mandatory for control of the disease. It is important to realise that most patients with malignant tumours are not cured by medical treatment but that the disease can be controlled for extended periods of time. In the future it will be possible to individualize treatments on the basis of new information about such features of tumour biology as proliferation capacity, expression of adhesion molecules, and growth factors and their receptors.

Advances in the management of patients with Zollinger-Ellison syndrome

A detailed description of recent advances in the management of patients with Zollinger-Ellison syndrome (ZES) is presented. The clinical presentation is reviewed, and newer diagnostic tools, both preoperative and intraoperative, are discussed. An update on surgical management is presented, including indications for abdominal exploration, intraoperative localization techniques, surgical excision, and the approach to patients with metastases or in whom no tumor is found. New strategies in the medical management of ZES also are reviewed. An update on patient survival is presented, and a review of the management of patients with multiple endocrine neoplasia type 1 and ZES is discussed.

Management of patients with Zollinger-Ellison syndrome

Zollinger-Ellison syndrome (ZES) is caused by gastrin-secreting tumors called gastrinomas. Patients commonly present with peptic ulcer disease and may have recurrent, multiple, and atypically located ulcers, e.g. in the jejunum. Alternatively, severe diarrhea may be the only presenting symptom. Patients with multiple endocrine neoplasia Type I (MEN-I) and ZES become symptomatic at an earlier age than patients with sporadic ZES. Patients with ZES have elevated fasting serum gastrin concentrations (> 100 pg/ml) and basal gastric acid hypersecretion (> 15 mEq/h). The secretin stimulation test is the best test to distinguish ZES from other conditions resulting in elevated gastrin levels. Gastric acid hypersecretion can be controlled in virtually all patients with H2-receptor antagonists or omeprazole, thus rendering total gastrectomy unnecessary. Computed tomography (CT), magnetic resonance imaging (MRI), radionuclide octreotide scanning, endoscopic ultrasound, and the selective arterial secretin injection test are the recommended imaging studies for localization of gastrinoma; nevertheless, 50% of gastrinomas are not evident on preoperative imaging studies. All patients with sporadic gastrinoma who do not have unresectable metastatic disease should undergo exploratory laparotomy for potential curative resection. With increased awareness of duodenal tumors, gastrinoma can be found in 80-90% of patients. Surgery may be the most effective treatment for metastatic gastrinoma if most or all of the tumor can be resected. The management of patients with MEN-I and ZES remains controversial. Some clinicians advocate an aggressive surgical approach, whereas others have had little success in rendering patients eugastrinemic.

Parenteral control of gastric acid hypersecretion in patients with Zollinger-Ellison syndrome

Parenteral control of gastric acid hypersecretion in patients with Zollinger-Ellison syndrome is increasingly required; however, existing methods of determining the required dose are cumbersome and not applicable in all centers. A previous study suggested that the required parenteral dose of histamine H2-receptor antagonists correlated with the previous oral dose. In the present study, in 31 patients with Zollinger-Ellison syndrome we evaluated the hypothesis that an effective parenteral histamine H2-receptor antagonist dose could be predicted from the previous oral dose. Twenty-three patients were taking oral ranitidine (mean 1.3 g/day), six patients famotidine (152 mg/day), and two patients cimetidine (1.8 g/day). Each patient was treated with a continuous intravenous infusion of the equivalent dose of ranitidine (mean dose 1 mg/kg/hr with 35% requiring 0.5 mg/kg/hr, 49% 1 mg/kg/hr, 3% 1.5 mg/kg/hr, 10% 2 mg/kg/hr, and 3% 2.5 mg/kg/hr. This dose of ranitidine acutely controlled acid secretion (< 10 meq/hr) in all patients. To evaluate long-term efficacy and safety, 20 patients were maintained on this dose through the peri- and postoperative periods. Mean duration was 7.1 days with 25% treated 3-5 days, 40% 6-8 days, 30% 8-10 days, and 5% > 10 days. The predicted dose continued to control acid secretion in 95% of patients with one patient requiring one dose adjustment. No biochemical, clinical, or hematological toxicity was seen, although ranitidine was stopped in one patient because of skin rash. These results demonstrate that the parenteral dose of ranitidine required to control acid secretion in patients with Zollinger-Ellison syndrome can be predicted from the oral dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Review article: the management of Zollinger-Ellison syndrome

Awareness of the sometimes subtle features of Zollinger-Ellison syndrome is important in order not to miss the diagnosis. Immediately after initial diagnostic tests, the patient should be given antisecretory medication, while tests for the type of Zollinger-Ellison syndrome and tumour extent can be delayed. Acid output should be decreased to < 10 mmol/h to control symptoms and prevent complications. Histamine H2-antagonists remain the best available intravenous therapy but omeprazole is the most effective long-term oral therapy and has proved to be safe in nearly 10 years of continuous use. The management of the gastrinoma has changed in recent years since the discovery that the majority of gastrinomas arise outside the pancreas. Exploratory surgery with tumour resection is the treatment of choice in sporadic Zollinger-Ellison syndrome but there are few indications for surgery in patients with Zollinger-Ellison syndrome and multiple endocrine neoplasia type-1. None of the available therapies for metastatic gastrinoma is very effective.

Assessment and prediction of long-term cure in patients with the Zollinger-Ellison syndrome: the best approach

OBJECTIVE

To identify the best method for determining freedom from disease after gastrinoma resection and for predicting long-term disease-free status in patients with the Zollinger-Ellison syndrome.

DESIGN

Prospective study in consecutive patients.

SETTING

Referral-based clinical research center.

PATIENTS

Eighty-one consecutive patients with the Zollinger-Ellison syndrome who underwent surgical exploration for gastrinoma resection.

INTERVENTION

Patients were evaluated after gastrinoma resection, before discharge, 3 to 6 months after surgery, and yearly thereafter. Evaluation included secretin provocative testing and fasting serum gastrin determinations. Follow-up examinations after the initial postoperative evaluations included a clinical assessment, acid secretion studies, a calcium provocative test, and various imaging studies.

MEASUREMENTS AND MAIN RESULTS

Most patients (96%) had gastrinomas. Freedom from disease was defined by improved symptoms, reduced acid output and antisecretory drug requirements, and a normal gastrin level, normal imaging studies, and negative gastrin provocative studies. Fifty-two percent of patients (n = 42) were disease-free immediately after surgery, 44% at 3 to 6 months, 42% at 1 year, and 35% by 5 years (mean follow-up, 39 months). The secretin provocative test was the first test to become positive in 45% of patients with a recurrence, the serum gastrin determination was the first test to become positive in 36%, and both tests became positive at the same time in 18%. No recurrence was first detected by imaging studies or by calcium provocative testing. Fasting serum gastrin levels and secretin provocative test results at different postoperative times can be used to predict the probability of a patient remaining disease free at 3 years. Patients with a normal gastrin level and a normal secretin provocative test immediately after surgery had a 3-year disease-free probability of 75%, and normal results on both tests at 6 months, 1 year, and 2 years yielded respective probabilities of 88%, 95%, and 100%.

CONCLUSIONS

Both the secretin provocative test and fasting serum gastrin determination are necessary for the early diagnosis of cases of recurrent disease after gastrinoma resection. The calcium provocative test and imaging studies do not detect any recurrences first. Fasting serum gastrin determinations and secretin provocative testing at different postoperative times can be used to predict the probability of a patient remaining disease free at 3 years.

A prospective study of intraoperative methods to diagnose and resect duodenal gastrinomas

OBJECTIVE

This study determined, prospectively, whether duodenotomy (DX) should be routinely performed in explorations for patients with Zollinger-Ellison syndrome (ZES).

SUMMARY BACKGROUND DATA

Duodenal gastrinomas are now being found with increasing frequency in patients with Zollinger-Ellison syndrome. The surgical approach used to detect these tumors is controversial. Some recommend intraoperative endoscopy with transillumination (IOE) at surgery, while others recommend routine DX.

METHODS

Beginning in 1989, the authors prospectively compared the ability of palpation, intraoperative ultrasound (IOUS), IOE, and DX (in that sequence) to detect gastrinomas in 35 consecutive patients with ZES. Each patient also underwent preoperative localization studies.

RESULTS

Thirty-three of 35 patients (94%) had tumor detected and excised; duodenal gastrinomas were excised in 27 patients (77%). The average size of the duodenal tumors was 0.8 cm, significantly smaller (p < 0.005) than the pancreatic and lymph node tumors in this series. Standard palpation after a Kocher maneuver identified 19 of the 31 duodenal tumors (61%) in the 27 patients. IOUS revealed only eight duodenal tumors (26%) and no new lesions. IOE identified 20 duodenal gastrinomas (64%) and 6 new lesions. DX identified 31 duodenal tumors (100%) and 5 additional tumors. The morbidity rate was 17%. One patient had a duodenal fistula after operation (2.8%) and subsequently recovered. No patient died.

CONCLUSIONS

These results demonstrate that the duodenum is the most common location for gastrinoma in patients with ZES (77%) and that DX to detect and remove duodenal gastrinomas should be routinely performed in all explorations for patients with ZES.

Control of gastric acid hypersecretion in the management of patients with Zollinger-Ellison syndrome

During the last 5 years important advances have occurred in the control of gastric acid hypersecretion in Zollinger-Ellison syndrome (ZES). The increased availability of potent gastric acid antisecretory agents such as histamine H2-receptor antagonists and more recently the H+K(+)-ATPase inhibitors such as omeprazole and lansoprazole have made it possible to medically control acid secretion in all patients. Increased understanding of the variation in antisecretory drug dosage between individual patients has led to identification of criteria to ensure effective antisecretory control and to the recognition of subgroups of patients who require special monitoring. Effective regimens for parenteral antisecretory control during surgery have been established. The importance of parathyroidectomy in patients with multiple endocrine neoplasia type I with ZES and the possible usefulness of highly selective vagotomy have been investigated. We review here the new data that led to increased understanding in each of these areas from our studies and studies by others.

Prospective study of the need for long-term antisecretory therapy in patients with Zollinger-Ellison syndrome following successful curative gastrinoma resection

A long-term cure is now possible in more than 30% of selected patients with Zollinger-Ellison syndrome who undergo gastrinoma resection. The need, however, for continued gastric acid antisecretory therapy in these patients remains controversial. The current study was designed to determine whether post-operative antisecretory therapy is needed in patients who have undergone successful gastrinoma resection and, if so, to attempt to define criteria with which to identify patients who require therapy. Twenty-eight consecutive patients who had previously undergone curative gastrinoma resection were prospectively studied. When antisecretory therapy was discontinued, 43% (12/28) of these patients developed gastro-oesophageal reflux, diarrhoea, acid-peptic symptoms or endoscopic evidence of acid-peptic disease within 2 weeks and were deemed to have failed a trial of antisecretory drug withdrawal. The remaining 57% (16/28) of patients who successfully discontinued antisecretory therapy were followed for a mean time of 31 months after withdrawal of therapy. Analysis of acid output studies pre-operatively, as well as at the time of drug withdrawal, demonstrated that patients who were unable to discontinue antisecretory therapy exhibited higher pre-operative maximal acid output values and higher basal acid output values at the time of attempted drug withdrawal than patients who were able to discontinue therapy. Despite these findings, there was significant overlap in acid output values between groups so that it was not possible to define specific acid output criteria for successful drug withdrawal. Pre-operative clinical characteristics, such as the presence or absence of gastro-esophageal reflux or acid-peptic disease, or post-operative laboratory values, such as the fasting serum gastrin level, did not correlate with the ability to discontinue antisecretory therapy. We conclude that following successful curative gastrinoma resection, 40% of patients still require antisecretory therapy and that both symptom evaluation as well as upper endoscopy should be used to guide attempted drug withdrawal. Although patients who are not able to discontinue therapy have significantly higher acid output measurements than those who are able to discontinue therapy, neither acid output criteria nor any other laboratory or clinical characteristics are able to predict the need for continued antisecretory therapy in these patients.

The Zollinger-Ellison syndrome. A collective surgical experience

A retrospective study of 90 surgically treated patients with the Zollinger-Ellison syndrome seen from 1958 through 1990 was performed. Fifteen patients had Zollinger-Ellison syndrome as a manifestation of multiple endocrine neoplasia type I. Preoperative tumor localization was positive in 46% of 54 patients studied. Gastrinomas were identified in 66% of patients, 38% of the tumors being malignant. Postoperative eugastrinemia was achieved in 11% of patients after a variety of surgical procedures. Exploratory laparotomy provides the only chance for cure and identifies the significant prognostic factors associated with long-term patient survival: small tumor size, extrapancreatic primary, and absence of tumor metastases.

Effects of curative gastrinoma resection on gastric secretory function and antisecretory drug requirement in the Zollinger-Ellison syndrome

The chronic hypergastrinemia in diseases such as the Zollinger-Ellison syndrome has trophic effects on the gastric mucosa, causing increased parietal cell mass reflected by increased maximal acid output (MAO) and basal acid output (BAO). The time course for the development of these gastric changes in humans is unknown, and controversy exists regarding whether reversal of the hypergastrinemia results in rapid normalization of gastric secretory function. To address these uncertainties, gastric secretory function was prospectively evaluated in 20 patients with the Zollinger-Ellison syndrome undergoing successful curative resection of gastrinoma. Each patient had gastric acid measurements, imaging studies, fasting serum gastrin and secretin provocative testing preoperatively, postoperatively at 3-6 months, and yearly thereafter. Preoperative mean BAO was 39 mEq/h, MAO 56 mEq/h, BAO-MAO ratio 0.73, and fasting gastrin output 1020 pg/mL. All patients were evaluated at 6 months, 17 at 1 year, 15 at 2 years, 13 at 3 years, and 9 at 4 years. By 3-6 months, MAO decreased by 50% in men (mean, 30 mEq/h) and by 35% in women (mean, 29 mEq/h) and then remained relatively unchanged for up to 4 years. Before surgery, 14 of 20 patients (70%) had an elevated MAO, whereas 4 years after resection, none of 9 patients had elevated levels. By 3-6 months, BAO decreased by 75% and remained unchanged for up to 4 years. At 3-6 months, 56% of patients were mild hypersecretors and 67% remained hypersecretors up to 4 years. Preoperatively, the BAO-MAO ratio was elevated in 16 of 20 patients (80%); postoperatively, only 5 of 18 patients (28%) at 3-6 months, 2 of 15 (13%) at 1 year, and 2 of 10 (20%) at 4 years continued to have elevated ratios. Preoperatively, the mean ranitidine dose was 1597 mg/day, whereas after surgery the mean dose was 535 mg/day at 3-6 months and approximately 300 mg/day at 1-4 years with 8 patients requiring no antisecretory drug. These results show that the trophic effects of chronic hypergastrinemia are, in general, rapidly reversible with a 50% decrease in MAO within 3-6 months of cure. Similarly, BAO decreased by 75% within 3-6 months. Despite these decreases, careful monitoring of acid secretion is required after reversal of the chronic hypergastrinemia in diseases such as the Zollinger-Ellison syndrome, because 55% of patients at 3-6 months and up to 67% at 4 years continue to remain mild hypersecretors and require low doses of antisecretory drugs.

Selective intra-arterial methylene blue injection: a novel method of localizing gastrinoma

A 40-year-old woman had persistent Zollinger-Ellison syndrome despite excision of a 4-cm duodenal gastrinoma. Localizing studies including ultrasonography, computed tomography, magnetic resonance imaging, duodenal endoscopy, endoscopic ultrasonography, and intraoperative endoscopic transillumination of the duodenum failed to detect a tumor. Selective intra-arterial methylene blue injection was used to identify a 6-mm gastrinoma in the duodenum, which was locally excised. Postoperatively, the patient had a negative secretin provocative test result. This novel method uses selective arterial secretin injection with hepatic venous gastrin sampling to identify the vessel feeding the gastrinoma. An angiographic catheter is then positioned in this artery. At laparotomy, methylene blue is injected through this catheter to selectively stain the gastrinoma, facilitating its identification. Selective intra-arterial methylene blue injection can enhance intraoperative detection of small gastrinomas and may improve the rate of curative resection in the Zollinger-Ellison syndrome. Further evaluation of this novel localizing technique is warranted.

Curative resection in Zollinger-Ellison syndrome. Results of a 10-year prospective study

Since 1980, 73 patients with Zollinger-Ellison syndrome (ZES) without radiographic evidence of liver metastases were studied on a prospective protocol including medical management of gastric acid hypersecretion, extensive radiographic tumor localization, and exploratory surgery to find and resect gastrinoma for potential cure. Each patient had gastric acid hypersecretion effectively controlled with either H2-blockers or omeprazole. Patients were divided prospectively into two groups, with all patients undergoing the same preoperative localization studies and extensive laparotomy. In contrast to group 1 (1980-1986) (36 patients), group 2 (1987-Oct. 1990) (37 patients) also underwent additional procedures (transillumination and duodenotomy) at surgery to find duodenal gastrinomas. Preoperative imaging studies localized tumor in 38 (52%) patients, and portal venous sampling for gastrin determinations was positive in 49 (67%) patients. Gastrinomas were found and resected in 57 (78%) patients. Significantly more gastrinomas (92% of patients) were found in group 2 than in group 1 patients (64%) (p less than 0.01). This increase was due to increased numbers of duodenal gastrinomas in group 2 than in group 1 patients (43% versus 11%; p less than 0.01). The increased ability to find duodenal gastrinomas did not significantly improve the immediate disease-free rate, which was 58% for all patients. Duodenal primary gastrinomas were found to have a significantly greater incidence of metastases (55%) and a significantly shorter disease-free interval (12 months) than pancreatic gastrinomas (22% and 84 months, respectively) suggesting that duodenal gastrinomas may be more malignant and not more frequently curable than pancreatic gastrinomas. Operations were performed with no deaths and 11% morbidity rate. Long-term follow-up showed that 50% of patients initially rendered disease free would develop recurrent disease by 5 years. Survival was excellent for all patients, and none died of malignant spread of the tumor or uncontrolled peptic ulcer disease, with a mean follow-up of 5 years. This finding is in contrast to patients who presented with metastatic disease on imaging studies and had a 20% 5-year survival rate. This study suggests that all patients with localized sporadic ZES can have the gastric acid hypersecretion managed medically, that overall survival of these patients is excellent, most (78%) can have all gastrinoma found and resected, and some (30%) will be cured (long-term disease-free survival).