An unforeseen twist: entero-enteric fistula in a patient with portomesenteric thrombosis after laparoscopic sleeve gastrectomy: a case report

Introduction

Bariatric surgery has emerged as a pivotal tool in the fight against obesity, offering substantial weight loss and metabolic benefits to patients. However, this therapeutic approach is not without its potential complications. Among the less common but severe postoperative complications, portomesenteric venous thrombosis (PMVT) after laparoscopic sleeve gastrectomy (LSG) represents a challenging diagnosis. In this report, we present a compelling case that discusses the relation between these complex entities and explores the diagnostic and therapeutic journey.

PMVT, characterized by thrombotic occlusion of the portal and mesenteric veins, can lead to intestinal ischemia and associated sequelae (1). While its association with bariatric surgery is uncommon, the increasing prevalence of these procedures warrants vigilant awareness of this potential complication (2). Concurrently, the formation of entero-enteric fistulas, which are abnormal connections between different segments of the intestine, adds a layer of complexity to the clinical scenario (3).

This case report describes a patient who underwent LSG and subsequently developed PMVT, ultimately leading to the development of entero-enteric fistulas. We provide a detailed description of the patient’s clinical presentation, diagnostic evaluations, surgical interventions, and postoperative management. The aim of this report is to share an instructive clinical experience that contributes to the understanding and management of this intricate complication. We present this article in accordance with the CARE reporting checklist (available at https://ales.amegroups.com/article/view/10.21037/ales-23-60/rc).

Case presentation

A 29-year-old female, with no significant medical or family history except for previous successful surgeries (tonsillectomy, appendectomy, and cholecystectomy), presented to our outpatient clinic in December 2022 with class III obesity [body mass index (BMI) 41.22 kg/m²]. After evaluation by the multidisciplinary bariatric surgery team, she underwent LSG with no complications, minimal blood loss and was discharged on postoperative day 1, on enoxaparin 40 mg/0.4 mL, once daily for one week as per institutional protocol (Figure 1). During the 15 days of follow-up after the surgery, she exhibited positive progress and did not report any symptoms.

Figure 1 Postoperative course from index surgery to last visit. TIPS, transjugular intrahepatic portosystemic shunt.

One month later she was readmitted due to bilateral flank pain and watery diarrhea, laboratory studies revealed severe leukocytosis [white blood cells (WBCs) of 26.9 per microliter]. A computed tomography (CT) scan showed thrombosis of the right, left, and main portal veins, along with superior mesenteric vein thrombosis (Figure 2). Despite initiating full anticoagulant therapy with a continuous heparin infusion (14 units/kg/h), her symptoms persisted. After 72 hours of anticoagulation the patient developed melena, so the heparin was discontinued, and she was transferred to the intensive care unit. A follow-up CT scan showed unchanged thrombosed veins, persistent small bowel wall thickening, mesenteric edema, progressive ascites, and veno-occlusive mesenteric ischemia (Figure 3). After a multidisciplinary decision, the patient underwent a thrombectomy and aspiration via transjugular intrahepatic portosystemic shunt (TIPS) assisted with trans-splenic access (Figure 4). However due to persistent clot burden, a catheter-directed thrombolysis with alteplase (10 mg in 1,000 mL 0.9% sodium chloride) was performed. The heparin drip was restarted after the procedure. The patient remained stable and was transferred back to the ward 5 days later. She remained hospitalized for 15 more days until her condition improved. She was discharged on day 16 (2 months after the index surgery) on warfarin 3.5 mg daily, and an anti-coagulation visit was scheduled every 7 days. The dose was later increased to 5 mg to maintain the international normalized ratio (INR) in therapeutic range.

Figure 2 Computed tomography of the first month after index surgery, shows thrombosis of the right, left, and main portal veins along with the superior mesenteric vein (red arrow).

Figure 3 Computed tomography 3 days after receiving full anticoagulation, shows persistent unchanged thrombosis (red arrow) and persistent mural thickening of small bowel (blue arrow).

Figure 4 TIPS assisted with trans-splenic access. (A) Access into the peripheral splenic vein revealed an occlusion at the level of the portal vein confluence and the superior mesenteric vein (red arrow). Thrombectomy was performed twice; however, due to the persistence of clot burden in the portal vein, a decision was made to place the shunt. (B) Access to the right hepatic vein allowed advancement to the portal vein, followed by dilation of the tract and placement of the transjugular intrahepatic portosystemic shunt (blue arrow) to facilitate blood flow and decompress the portal vein. TIPS, transjugular intrahepatic portosystemic shunt.

Three months after the index surgery, and 1 month after her last discharge, she was readmitted due to abdominal pain and vomiting. A CT scan showed thickened bowel walls, and a small amount of fluid within the leaves of the mesentery, which led to a diagnosis of focal infectious enteritis (Figure 5). Antibiotic treatment was provided with intravenous (IV) ciprofloxacin 400 mg every 12 hours and metronidazole 500 mg every 8 hours. The patient was discharged 2 days later with oral antibiotics (metronidazole 500 mg every 8 hours for 3 days). During the next month the patient visited the emergency department on three occasions due to persistent abdominal pain, vomiting and diarrhea which were managed conservatively with symptomatic treatment without hospitalization. Despite several outpatient complementary studies, including an upper and lower endoscopy, the cause of the symptoms remained uncertain. Finally, 4 months after the index surgery, the patient was admitted again. An abdominal magnetic resonance imaging (MRI) revealed an interloop fistulous communication between the jejunum and ileum (Figure 6). To improve her nutritional status in preparation for surgery, central parenteral nutrition was initiated because of a total body weight loss of 30 kg since the index surgery. After 20 days, she underwent a diagnostic laparoscopy that revealed severe adhesions between the small bowel and sigmoid colon, therefore a conversion to a mini laparotomy was required. The intraoperative findings included severe adhesions (mostly at the left iliac fossa), dilated and thickened walls in the proximal small bowel up to about 50 cm from the duodenojejunal junction, and an entero-enteric fistula of the small bowel (jejunum-jejunum) accompanied by severe adhesions and a mass-like structure. This inflammatory mass, located 45 cm from the duodenojejunal junction, was resected. A side-to-side anastomosis was then performed under sterile technique. The patient was transferred to the postoperative care unit and then back to her room stable. Histopathology confirmed acute and chronic inflammation of the small bowel, with a fistulous tract between two segments of small intestine (26 and 18 cm in length, respectively), lined by inflammatory granulation tissue. She demonstrated a favorable response, tolerating full liquid diet and was discharged 6 days after the laparotomy.

Figure 5 Computed tomography 3 months after the index surgery, shows a focal prominent loop of ileum in the left lower quadrant which has bowel thickening and small amount of fluid within the adjacent mesentery (red arrow).

Figure 6 Abdominal magnetic resonance imaging 4 months after index surgery. It shows a local segment of dilated jejunal loop with circumferential wall thickening, hyperenhancement and restriction of diffusion compatible with active inflammatory changes (red arrow). An interloop fistulous communication between jejunum and ileum is seen in the lower left quadrant (blue arrow).

Seven days later (7 months after the index surgery), the patient developed fever, chills, and nausea. A CT scan revealed an intraabdominal abscess along the jejunal loops (Figure 7). The patient was started on antibiotic therapy (piperacillin-tazobactam) and scheduled for drain placement under ultrasound and fluoroscopic guidance. Abdominal liquid drainage revealed the presence of Escherichia coli resistant to piperacillin-tazobactam, so the therapy was switched to cefoxitin. On the fourteenth day of hospitalization the drain was removed, and the patient was discharged the following day stable. During the next few weeks, the patient reported a good recovery, with resolution of her symptoms and satisfaction with the treatment received. The patient’s last visit for follow-up was 8 months after the LSG (2 months after the laparotomy and 1 month after the drainage) she continued showing a good recovery, with adequate oral intake and no symptoms. She is still under anticoagulation with rivaroxaban managed by the hematology department.

Figure 7 Computed tomography of 7 months after index surgery. It shows complex loculated fluid collection with peripheral enhancement, along the left lateral aspect of thickened jejunal loops (red arrow). Prominent inflammation of the adjacent mesenteric fat planes.

Ethical statement

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). Written informed consent for publication of this case report and accompanying images was not obtained from the patient or the relatives after all possible attempts were made.

Discussion

PMVT is an uncommon, yet well-established complication after LSG. PMVT has been increasingly reported in recent years as the number of bariatric surgeries performed worldwide grows. Shaheen et al. found that the incidence of PMVT after LSG ranges from 0.37% to 1% (2). Correspondingly, Carrano et al. reported a total of 34 cases with confirmed PMVT-related to LSG on an online survey performed on members of the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) (4).

Various factors have been associated with the risk of developing PMVT after LSG from prothrombotic states to local elements; such as increased intra-abdominal pressure which causes reduced blood flow within the portal vein (2). Frattini et al. analyzed some pathogenetic factors that explain the relation between PMVT and LSG, including the use of 38 Fr calibration boogie for the sleeve, which increases the intraluminal gastric pressure (1). As well as the use of energy devices for coagulation of short gastric vessels, which can provide the ideal environment for thrombus development (5).

A systematic review about PMVT after LSG revealed that 65.8% of patients experienced epigastric pain, while fever, tachycardia and elevated WBC were reported in less than 30% of patients (2). Notably, it was the abdominal pain that led our patient to visit the emergency department, highlighting the importance of providing comprehensive education about post-operative symptoms that should serve as warning signs for potential postoperative complications. The diagnosis of PMVT was performed with CT alone similar to the experience published by Tan et al. in 2018, where 56% of all patients with PMVT were diagnosed with CT alone, while 32% required both CT and duplex ultrasound (6).

The optimal management strategy for patients with PMVT after LSG has not been well established, and further research is required to determine the best approach. The management of PMVT should involve reversing thrombus progression and prevention of complications (2). Early anticoagulation enhances the possibility of recanalization without additional therapy, however complete recanalization has been reported in as little as 38.3% of patients, with the rest needing alternative therapies (7). Our patient developed thrombosis despite being on prophylactic anticoagulation following institutional protocol. After the diagnosis, we promptly initiated full anticoagulation therapy with continuous heparin infusion, adhering to international standards of management. Regrettably, the patient experienced melena, prompting an escalation of treatment and scheduling for intervention. The decision to initiate thrombolysis instead of continuing anticoagulation was made based on the evolving clinical scenario. This approach was employed by Shaheen et al. in 5 out of 89 patients, who underwent thrombolytic therapy for PMVT after LSG with a good prognosis (2). It is important to acknowledge the limitations in existing high quality research comparing full anticoagulation to thrombolytic therapy in this setting, however, retrospective cohorts show high rates of recanalization in patients who underwent thrombolysis following failed heparin therapy, as with our patient (8). Chamarthy et al. support this approach for patients who have symptomatic acute and subacute portal vein thrombosis without bowel infarction (9).

This medical condition is distinctive as it underscores an infrequent complication: the formation of an entero-enteric fistula resulting from PMVT after LSG. To our knowledge, such fistulas have not been previously reported in this specific context. Spontaneous fistulas have been associated with pancreatitis, inflammatory bowel disease, radiation, diverticular disease, bowel ischemia and malignancy (10).

While uncommon, PMVT might be responsible for bowel ischemia in approximately 6–9% of patients (11). Upon thorough examination of the medical literature, we found that the sole other publication on an entero-enteric fistula in a similar setting was by Khan et al. in 2018. They documented two instances of entero-enteric fistulas resulting from ischemia: one following arterial thrombosis and another post PMVT (3). Patients usually present with abdominal pain, diarrhea, weight loss, abscesses, and sepsis (12). After establishing the diagnosis, they need several weeks of conservative management before undergoing a surgical repair usually reserved for symptomatic cases (13). Surgery aims to resect the fistula and reestablish a functioning bowel with an anastomosis (14). In this case, our patient required a mini-laparotomy due to complexity of the ongoing symptoms and limited response to previous treatments.

Despite facing multiple complications, our patient did not experience excessive weight loss after the LSG (defined as reaching a BMI of 18.5 kg/m² or less after bariatric surgery) (15). However, a nutritional assessment prior to the fistula resection did reveal a state of malnutrition, characterized by hypoalbuminemia and low prealbumin. The complex clinical progress experienced by our patient, marked by multiple complications and a poor nutritional state, prompts consideration of the profound impact such challenges can have on weight loss after bariatric surgery. Interestingly, a study conducted by Coblijn et al. in the context of Roux-en-Y gastric bypass demonstrated that short-term complications did not alter weight loss (16). Further studies are needed to determine if these findings can be extrapolated to LSG. Nevertheless, it is essential to note that, to optimize patient prognosis and facilitate full recovery, it becomes imperative to address and rectify malnutrition.

This clinical case sets a precedent, indicating that after LSG PMVT followed by ischemia can also lead to the development of entero-enteric fistulas. Among the challenges presented while preparing this report were the lack of high-quality evidence regarding this complication and the extended period of time in which this type of pathology develops. Nonetheless we aimed to summarize an extensive clinical record to provide a clear and concise understanding of this medical condition. In conclusion, additional research is essential to understand the precise pathophysiology behind ischemia resulting from venous thrombosis and its role in the development of such fistulas. This would also pave the way for establishing treatment guidelines for entero-enteric fistulas arising from bowel ischemia.

Conclusions

This clinical case underscores the need for vigilance in post-LSG patients who present with unusual and recurring symptoms. It also emphasizes the importance of a multidisciplinary approach for these patients, who require complex management by various specialties including general surgeons, radiologists, and gastroenterologists. A high level of suspicion is needed to diagnose patients who develop complications at various stages of their recuperation. Entero-enteric fistulas should be considered as a possibility when patients present with recurring abdominal pain and poor clinical progress, especially after an episode of possible bowel ischemia, such as with PMVT.

Acknowledgments

Funding: None.

Footnote

Reporting Checklist: The authors have completed the CARE reporting checklist. Available at https://ales.amegroups.com/article/view/10.21037/ales-23-60/rc

Peer Review File: Available at https://ales.amegroups.com/article/view/10.21037/ales-23-60/prf

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://ales.amegroups.com/article/view/10.21037/ales-23-60/coif). A.D.G. serves as an unpaid editorial board member of Annals of Laparoscopic and Endoscopic Surgery from August 2022 to July 2024. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration (as revised in 2013). Written informed consent for publication of this case report and accompanying images was not obtained from the patient or the relatives after all possible attempts were made.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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