Stenting of the Superior Mesenteric Vein in Midgut Carcinoid Disease with Large Mesenteric Masses

Endovascular Stenting for Idiopathic Stenosis of the Superior Mesenteric Vein: A Case Report

Idiopathic superior mesenteric vein (SMV) stenosis, where no clear causative factor is identifiable, remains a clinical rarity. We present a detailed case report of a patient with idiopathic stenosis of the SMV who underwent successful endovascular stenting. This report outlines the patient's clinical presentation, diagnostic imaging findings, procedural approach by the interventional radiology team, and subsequent management. Endovascular stenting is a viable therapeutic option for patients with idiopathic SMV stenosis. This case demonstrates that with appropriate interventional and post-procedural management, long-term stent patency and thrombosis prevention can be achieved. The success of this case encourages further investigation into endovascular treatments for venous stenoses.

Surgery for advanced neuroendocrine tumours of the small bowel: recommendations based on a consensus meeting of the European Society of Endocrine Surgeons (ESES)

BACKGROUND

Small bowel neuroendocrine tumours often present with locally advanced or metastatic disease. The aim of this paper is to provide evidence-based recommendations regarding (controversial) topics in the surgical management of advanced small bowel neuroendocrine tumours.

METHODS

A working group of experts was formed by the European Society of Endocrine Surgeons. The group addressed 11 clinically relevant questions regarding surgery for advanced disease, including the benefit of primary tumour resection, the role of cytoreduction, the extent of lymph node clearance, and the management of an unknown primary tumour. A systematic literature search was performed in MEDLINE to identify papers addressing the research questions. Final recommendations were presented and voted upon by European Society of Endocrine Surgeons members at the European Society of Endocrine Surgeons Conference in Mainz in 2023.

RESULTS

The literature review yielded 1223 papers, of which 84 were included. There were no randomized controlled trials to address any of the research questions and therefore conclusions were based on the available case series, cohort studies, and systematic reviews/meta-analyses of the available non-randomized studies. The proposed recommendations were scored by 38-51 members and rated 'strongly agree' or 'agree' by 64-96% of participants.

CONCLUSION

This paper provides recommendations based on the best available evidence and expert opinion on the surgical management of locally advanced and metastatic small bowel neuroendocrine tumours.

Surgical aspects of small intestinal neuroendocrine tumors

Small intestinal neuroendocrine tumors (NETs) are a heterogeneous group of epithelial tumors with a predominant neuroendocrine differentiation. Although NETs are usually considered rare neoplasms, small intestinal NETs are the most common primary malignancy of the small bowel, with an increasing prevalence worldwide during the course of the past few decades. The indolent nature of these tumors often leads to a delayed diagnosis, resulting in over one-third of patients presenting with synchronous metastases. Primary tumor resection remains the only curative option for this type of tumor. In this review article, the various surgical aspects for the excision of small intestinal NETs are discussed.

Percutaneous transhepatic stent for chronic intestinal bleeding from jejunal varices in primary idiophatic superior mesenteric vein stenosis: A case report

Jejunal varices are a rare cause of gastrointestinal bleeding. In most cases, they are due to portal hypertension related to liver cirrhosis, less frequently to superior mesenteric vein stenosis (SMV). In this article we describe an unusual case of a 61 year-old male patient who arrived at our emergency department with intermittent variceal bleeding due to jejunal varices causing melena and subsequent chronic anaemia. Patient was indeed discovered to have primary idiopathic superior mesenteric vein stenosis. We managed to treat this patient via SMV stenting through percutaneous transhepatic approach. In cases of upper-GI bleed with negative endoscopy for active bleeding, a contrast-enhanced CT scan should be performed to diagnose jejunal varices and their underlying cause, such as SMV stenosis which is best treated with percutaneous phlebography.

How to Manage Small Intestine (Jejunal and Ileal) Neuroendocrine Neoplasms Presenting with Liver Metastases?

PURPOSE OF REVIEW

Small intestinal neuroendocrine neoplasms (siNENs) are slowly growing tumours with a low malignant potential. However, more than half of the patients present with distant metastases (stage IV) and nearly all with locoregional lymph node (LN) metastases at the time of surgery. The value of locoregional treatment is discussed controversially.

RECENT FINDINGS

In stage I to III disease, locoregional surgery was currently shown to be curative prolonging survival. In stage IV disease, surgery may prolong survival in selected patients with the chance to cure locoregional disease besides radical/debulking liver surgery. It may improve the quality of life and may prevent severe local complications resulting in a state of chronic malnutrition and severe intestinal ischaemia or bowel obstruction. Locoregional tumour resection offers the opportunity to be curative or to focus therapeutically on liver metastasis, facilitating various other therapeutic modalities. Risks and benefits of the surgical intervention need to be balanced individually.

Management of Locally Advanced and Unresectable Small Bowel Neuroendocrine Tumours

Three subtypes of small bowel neuroendocrine tumours (SBNETs) have been described: Type A: SBNET with resectable mesenteric disease that does not involve the mesenteric root; Type B: "Borderline resectable" SBNET presenting with mesenteric nodal metastases and fibrosis adjacent but not encasing the main trunk of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV); and Type C: "Locally advanced or irresectable" SBNET where tumour deposits and fibrosis encase the SMA and SMV. Type C SBNETs are rare and constitute around 5% of patients in reported series, although this may underestimate the prevalence. In these patients, almost all will present with symptoms of intestinal ischemia or obstruction and symptom management should be a primary main focus of treatment. All patients should be carefully staged with cross-sectional imaging and 68 Ga-dotate positron emission tomography, and discussed at a dedicated neuroendocrine tumour multidisciplinary meeting. Expert surgical review should always be sought as experienced centers have a high rate of successful resection of primary tumours and mesenteric disease. If resection is not feasible, surgical bypass should be considered in patients with a discrete and symptomatic point of obstruction. Non-operative management should emphasize symptomatic treatment with somatostatin analogs, nutritional advice and support and palliative care. Successful neoadjuvant approaches utilizing peptide radionucleide receptor therapy and systemic chemotherapy with everolimus or temazolamide/capecitabine have not been reported.

Surgery and Perioperative Management in Small Intestinal Neuroendocrine Tumors

Small-intestinal neuroendocrine tumors (SI-NETs) are the most prevalent small bowel neoplasms with an increasing frequency. In the multimodal management of SI-NETs, surgery plays a key role, either in curative intent, even if R0 resection is feasible in only 20% of patients due to advanced stage at diagnosis, or palliative intent. Surgeons must be informed about the specific surgical management of SI-NETs according to their hormonal secretion, their usual dissemination at the time of diagnosis and the need for bowel-preserving surgery to avoid short bowel syndrome. The aim of this paper is to review the surgical indications and techniques, and perioperative and postoperative management of SI-NETs.

Percutaneous Transhepatic Approach for Recanalization of Superior Mesenteric and Portal Vein in a Patient With Pancreatic Neuroendocrine Tumor Presenting With Bleeding Duodenal Varices: A Brief Case Report

Occlusion of Portal Vein (PV) and Superior Mesenteric Vein (SMV) is a known effect of local infiltration by pancreatic or mesenteric neuroendocrine tumors. Venous occlusion leads to formation of collateral pathways to restore hepatopetal flow in main PV and these collateral pathways can be seen in the form of ectopic (duodenal or jejunal) varices. We present a case of bleeding duodenal varices secondary to SMV occlusion by a locally infiltrating pancreatic neuroendocrine tumor which was successfully treated by coil embolization of varices and SMV stenting of the occluded venous segment after failure of endoscopic glue injection. Various endovascular minimally invasive approaches have been described in literature for recanalization of SMV in such clinical scenarios which maybe challenging to treat for surgical methods. We recommend use of the retrograde transhepatic technique for recanalization of occluded SMV and embolization of associated varices as an alternate treatment option in such scenarios.

Neoadjuvant peptide receptor radionuclide therapy and modified multivisceral transplantation for an advanced small intestinal neuroendocrine neoplasm: an updated case report

Small intestinal neuroendocrine neoplasms (SI-NEN) frequently metastasise to regional lymph nodes, and surgery is the mainstay of therapy for such patients. However, despite the possible use of advanced surgical techniques, the resection of both primary and locoregional diseases is not always attainable. Intestinal and multivisceral transplantation has been performed in a small number of patients with conventionally nonresectable, slow-growing tumours threatening the mesenteric root but has remained controversial. The use of donor skin in “sentinel flaps” in transplantation theoretically offers advantages in tailoring immunosuppression and monitoring for rejection. We represent (with extended follow-up) the first case of a patient with inoperable extensive mesenteric metastases from SI-NEN, who underwent neoadjuvant peptide receptor radionuclide therapy before a modified multivisceral transplant with a concomitant vascularised sentinel forearm flap. At 48 months after transplantation, our patient remained at full physical activity with no evidence of disease recurrence on either tumour biochemistry or radiological imaging.

Clinical signs of fibrosis in small intestinal neuroendocrine tumours

BACKGROUND

In patients with small intestinal neuroendocrine tumours (SI-NETs), serotonin and other cytokines released from tumour cells may induce fibrosis, leading to carcinoid heart disease and abdominal fibrotic reactions. The aim of this study was to assess the prevalence, clinical complications and management of this reaction in the abdomen.

METHODS

This was a retrospective cohort study of patients with SI-NETs diagnosed between 1985 and 2015. Clinical data, outcomes, radiological findings, and surgical and radiological interventions were reviewed.

RESULTS

A total of 824 patients were diagnosed with SI-NETs in the study interval. Clinically significant abdominal signs and symptoms of fibrosis occurred in 36 patients. Of these, 20 had critically symptomatic central mesenteric fibrosis causing obstruction of mesenteric vessels, and 16 had retroperitoneal fibrosis causing obstructive uropathy with hydronephrosis. Extensive fibrosis causing mesenteric vessel obstruction and/or obstructive uropathy was more often associated with symptomatic and advanced disease encompassing lymph node metastases in the mesenteric root, para-aortic lymph node metastases, as well as liver metastases and peritoneal carcinomatosis. Palliative intervention in terms of superior mesenteric vein stenting or resection of central mesenteric metastases and/or percutaneous nephrostomy and J stent treatment was beneficial in the majority of the patients.

CONCLUSION

Extensive abdominal fibrosis associated with clinically significant symptoms of intestinal ischaemia and/or obstructive uropathy was linked to advanced disease in patients with SI-NETs. Prompt recognition and minimally invasive intervention was effective in disease palliation.

Toward a Preoperative Classification of Lymph Node Metastases in Patients with Small Intestinal Neuroendocrine Tumors in the Era of Intestinal-Sparing Surgery

INTRODUCTION

In patients with small intestinal neuroendocrine tumors (siNETs), surgical resection of the primary tumor and associated mesenteric lymph nodes (LNs) is recommended, but is not well standardized and can be risky in patients with superior mesenteric vessel involvement.

OBJECTIVE

We aimed to evaluate the correlation between the length of resected small bowel and the number of removed LNs, and to propose a preoperative morphological classification of siNET-associated LNs.

METHODS

The records of patients operated on for siNETs at two expert centers between August 2005 and November 2013 were analyzed. Two specialist radiologists reviewed the preoperative imaging and classified mesenteric LNs into five stages according to their proximity to the trunk and/or branches of the superior mesenteric artery.

RESULTS

72 patients were included. The mean number of removed LNs was 12 ± 15 and the length of removed small intestine was 53 ± 43 cm. No correlation existed between the length of small bowel resection and the number of removed LNs. Overall, 9 (12%), 13 (18%), 36 (50%), 14 (19%) and 0 patients were classified into LN stages 0, I, II, III and IV. The correlation rate between the two observers was 0.98. Patients with LN stage III (hardly resectable) had more removed LNs than those with LN stages 0, I or II (easily removable).

CONCLUSION

Optimal lymphadenectomy is not always associated with extended small bowel resection. In the era of small bowel-sparing surgery, the preoperative classification of mesenteric LNs could help to standardize the surgical management of patients with siNETs.

Retrograde Stenting Under Transmesenteric Angiographic Guidance of an Occluded Superior Mesenteric Vein to Treat Life-Threatening Hemorrhage

Midgut carcinoid tumors (MCTs) are responsible for a range of mesenteric vascular complications and may rarely manifest with gastrointestinal (GI) hemorrhage. Endovascular approaches are particularly useful for this population, as surgery is often technically difficult. We report a case of life-threatening upper GI bleeding in a 50-year-old man previously diagnosed with an MCT in the small bowel mesentery. Computed tomography angiogram revealed an MCT obstructing the superior mesenteric vein (SMV) associated with multiple large collateral vessels. The patient underwent retrograde stenting of the obstructed SMV using a combined open and endovascular approach to successfully terminate the persistent GI bleeding.

Mesenteric changes in an ultrasound examination can facilitate the diagnosis of neuroendocrine tumors of the small intestine

Neuroendocrine tumors make up an interesting pathology of a variable clinical picture, prognosis, localization, endocrine activity and degree of malignancy.

Percutaneous treatment of symptomatic superior mesenteric vein stenosis using self-expanding nitinol stents

PURPOSE

To evaluate the technical and clinical success of percutaneous superior mesenteric vein (SMV) stenting in symptomatic patients using self-expanding nitinol stents.

METHODS

We retrospectively analyzed the technical and clinical success of percutaneous SMV stenting of 6 symptomatic patients (3 men, mean age 67 years, range 48-81 years). Stenosis of the SMV was caused by postoperative stricture (n=3), pancreas carcinoma (n=1) and pancreatitis (n=2). As a result of the stenosis, 3 patients had symptomatic ascites, 2 patients showed signs of mesenteric ischemia and 1 patient had recurrent gastrointestinal bleeding. Stenting was performed by a percutaneous transhepatic approach using self-expanding nitinol stents.

RESULTS

Stenting of the SMV was technically and clinically successful in all patients. No peri-interventional complications occurred. The stent diameters ranged from 6 to 14 mm. During the mean follow-up of 6 months (range, 2-10 months) 1 patient presented early stent occlusion 2 weeks after placement.

CONCLUSION

Stenting of a symptomatic SMV stenosis using self-expanding nitinol stents is feasible and clinically effective.

Modified liver-free multivisceral transplantation for a metastatic small bowel neuroendocrine tumor: a case report

Neuroendocrine tumors originating from the small bowel frequently metastasize to the lymph nodes and/or liver. Although surgical extirpation of the primary tumor and locoregional metastases epitomizes the management of patients with such tumors, this is not always possible with conventional surgical techniques. Nonresectable, slow-growing tumors involving the mesenteric root represent a generally accepted indication for deceased donor intestinal and multivisceral transplantation. Furthermore, vascularized sentinel forearm flaps offer opportunities for monitoring graft rejection and tailoring immunosuppression regimens. Here, we report the first documented case of modified liver-free multivisceral transplantation preceded by neoadjuvant 177-lutetium peptide receptor radionuclide therapy in a patient with a small bowel neuroendocrine tumor and extensive lymph node metastases in the mesenterium. At a follow-up of 21 months the patient is biochemically and radiologically disease-free.

Percutaneous transhepatic placement of a stent-graft to treat a delayed mesoportal hemorrhage after pancreaticoduodenectomy

Postoperative hemorrhage is one of the most severe complications after pancreaticoduodenectomy. While detection of bleeding from adjacent arteries via conventional angiography and treatment with endovascular arterial coil embolization has been well established, to date no reports of percutaneous therapy for mesoportal hemorrhage have been published. This article describes an unusual case of delayed post-pancreaticoduodenectomy hemorrhage detected on a fluoroscopic drain check and treated with percutaneous transhepatic covered stent placement.

Small bowel neuroendocrine tumors: the benefits of surgical intervention

Well-differentiated SI NETs are on the rise. Due in part to the indolent nature of these tumors, patients typically have a delay in diagnosis and present with metastatic disease. Surgeries for symptoms of either chronic intermittent small bowel obstruction and/or ischemia or from carcinoid syndrome have proven to provide excellent palliation. Most recently, several series have demonstrated an improved survival in those patients in whom the primary, locoregional disease has been resected. Several newer adjuncts have been developed to aid in the hepatic directed therapies such as ablation therapies, embolization and Y spheres. The ability to cytoreduce 70% or more of the hepatic tumor burden has been shown to not only to provide a biochemical and as such a clinical response, but also appears to prolong survival. All patients with SI NETs should be assessed in a multidisciplinary clinic and the first line of therapy should always be to assess surgical resectabilty.

Surgical treatment of neuroendocrine tumors (including carcinoid)

PURPOSE OF REVIEW

Neuroendocrine tumors of the gastrointestinal tract are rare tumors, but as they have become recognized more often, and their care has been concentrated at some centers, standards of care have developed. With these standards, questions in the field have led to focused studies to inform practitioners.

RECENT FINDINGS

The efficacy and morbidity of care have been well delineated now for pancreatic neuroendocrine tumors, as well as the effect of stretching the bounds of resection to include vascular reconstruction. The management of the gallbladder in patients with mid-gut carcinoid tumors and palliative approaches to mesenteric vein compression have been reported. The operative management of liver metastases shows the benefit of this approach, even when incomplete, as well as the safety of performing complex procedures in appropriate situations.

SUMMARY

Some of the difficult or controversial decision areas in the surgical care of patients with neuroendocrine tumors are now more clear because of recently reported data.

Partial abdominal evisceration and intestinal autotransplantation to resect a mesenteric carcinoid tumor

Background

Midgut carcinoids are neuroendocrine tumors that commonly metastasize to the intestinal mesentery, where they predispose to intestinal obstruction, ischemia and/or congestion. Because of their location, many mesenteric carcinoid tumors are deemed unresectable due to the risk of uncontrollable bleeding and prolonged intestinal ischemia.

Case Presentation

We report the case of a 60-year-old male with a mesenteric carcinoid tumor obstructing his superior mesenteric vein, resulting in intestinal varices and severe recurrent GI bleeds. While his tumor was thought to be unresectable by conventional techniques, it was successfully resected using intestinal autotransplantation to safely gain access to the tumor. This case is the first described application of this technique to carcinoid tumors.

Conclusions

Intestinal autotransplantation can be utilized to safely resect mesenteric carcinoid tumors from patients who were not previously thought to be surgical candidates. We review the literature concerning both carcinoid metastases to the intestinal mesentery and the use of intestinal autotransplantation to treat lesions involving the mesenteric root.