Living donor liver transplantation (LDLT) was first reported in 1989. Recently, LDLT has become a common practice in regions with a scarcity of deceased donors.¹ In many centers, a right liver graft is often used for LDLT to meet the metabolic demands of larger recipients.¹ However, when this graft excludes the middle hepatic vein (MHV), venous drainage from the anterior sector can be compromised, potentially leading to postoperative congestion and graft dysfunction.^1,2 Consequently, reconstruction of the MHV is critical to maintain blood flow and prevent graft failure.

An expanded polytetrafluoroethylene (ePTFE) graft is one of the various types of vascular grafts that can be used for the reconstruction of the MHV (Fig. 1).² While the safety of ePTFE grafts in LDLT has been established, reports have described a rare complication involving graft migration. Most patients with this complication have experienced migration of the ePTFE graft into the upper gastrointestinal (GI) tract, with the majority displaying a severe state necessitating surgical intervention.

Figure 1. Photographs depicting the reconstruction of the middle hepatic vein during living donor liver transplantation.

However, we herein report three cases of ePTFE graft migration into the upper or lower GI tract. These patients did not experience serious clinical symptoms and were successfully treated with endoscopic foreign body removal, without complications.

Case 1

A 56-year-old male presented at a primary care clinic with dyspepsia, 3 years after LDLT. He had been diagnosed with hepatitis B-related liver cirrhosis in 2005 and underwent LDLT on June 21, 2012, at Daegu Catholic University Medical Center (DCUMC). Esophagogastroduodenoscopy (EGD) was performed at the primary clinic. Following EGD, the patient was referred to DCUMC with a suspected phytobezoar. At DCUMC, repeat EGD revealed a 9-cm greenish foreign body in the duodenal bulb and the second portion, which was subsequently removed endoscopically using rat-tooth forceps (Fig. 2). The foreign body was identified as an ePTFE graft, which had been used to reconstruct the MHV during LDLT. After removal, the mucosa exhibited ulceration and granulation tissue in the duodenal bulb. Following the procedure, the patient’s symptoms improved without complications. He is currently undergoing outpatient follow-up and has not experienced any further issues.

Figure 2. Migrated graft from the first case. (A) A greenish foreign body located in the duodenum, initially misidentified as a phytobezoar during previous esophagogastroduodenoscopy at a local clinic. (B) The extracted foreign body, measuring 9 cm, was identified as polytetrafluoroethylene graft material.

Case 2

A 65-year-old male, who had undergone LDLT for alcoholic liver cirrhosis and hepatocellular carcinoma 6 years earlier, presented to the emergency room with hematochezia. A complete blood count revealed a hemoglobin level of 8.5 mg/dL, a decrease from 11.8 mg/dL of the previous week. No bleeding source was identified on EGD. Following bowel preparation, colonoscopy was performed, revealing multiple diverticula in the ascending colon but no active bleeding. Additionally, a greenish foreign body measuring approximately 7.5 cm was observed at the hepatic flexure (Fig. 3). This body, later identified as an ePTFE graft, was attached to the deformed colonic wall by a thin thread and was successfully removed using a snare after cutting the thread. Following the removal of the ePTFE graft, the patient experienced no further symptoms, including hematochezia, and was discharged without complications. Based on follow-up visits at the outpatient clinic, he has remained in good health.

Figure 3. Migrated graft from the second case. (A, B) A greenish foreign body was identified in the hepatic flexure, attached to the deformed colonic wall by a thin thread. (C) The removed foreign body, measuring 7.5 cm, was identified as polytetrafluoroethylene graft material.

Case 3

A 65-year-old female patient underwent LDLT in 2013. In 2020, she experienced endoscopic submucosal dissection for early gastric cancer and subsequently underwent follow-up EGD examinations every 6 months. At one of these evaluations in July 2022, a green foreign body was observed in the duodenal bulb, suspected to be a part of ePTFE migrating into the duodenal lumen. At that time, the patient’s vital signs were stable, and she reported no significant GI symptoms. After consultation with the surgeon, a cautious follow-up approach was selected. In December 2022, follow-up EGD revealed that the object had migrated further into the duodenal lumen compared to the previous examination (Fig. 4). An attempt to extract it with rat-tooth forceps was unsuccessful. The next follow-up endoscopy, conducted in June 2023, allowed the successful removal of the almost completely migrated foreign body using a snare. As suspected, it was confirmed to be an ePTFE graft. The patient has since been doing well, with no symptoms or recurrence of gastric cancer.

Figure 4. Migration of the graft in the third case. (A) A greenish foreign body is visible in the duodenal bulb. (B) The foreign body appears to be trapped within a fistula. (C) Six months later, the graft was successfully removed using a snare.

Since intrahepatic venous collaterals are expected to develop by day 7 following LDLT, ensuring anterior segment drainage of the graft is crucial, particularly during the first week after transplantation. Consequently, reconstructing the anterior segment drainage is necessary to prevent congestion and dysfunction of the right liver graft during LDLT.³ For MHV reconstruction, various materials have been utilized, including autologous veins from the donor or recipient, cryopreserved venous grafts, or synthetic grafts such as PTFE or Dacron. Currently, ePTFE grafts are frequently employed.

Complications associated with an ePTFE graft include thrombosis, infection, and graft migration. Previous studies have reported rates of ePTFE graft migration into adjacent organs ranging from 0.5% to 4.7%.^3,4 To our knowledge, 26 cases of ePTFE graft migration have been reported. An overview of previously reported instances of ePTFE graft migration into adjacent organs, including the present cases, is summarized in Table 1.^2–9

Table 1 . Cases of ePTFE Graft Migration into Adjacent Organs.

Author	Age (yr)	Sex	Migration site	Symptom	Interval after LDLT (mo)	Management method
Hsu et al2	67	F	Duodenum	Gastrointestinal bleeding	13	Surgical
	63	F	Duodenum	Fever	12	Surgical
	22	M	Duodenum	Fever	5	Surgical
Woo et al3	38	M	Duodenum	Dyspepsia	128	Endoscopic
	63	M	CBD	Fever	33	ERBD
	46	M	CBD	Abdominal pain, itching	35	PTBD
	48	F	CBD	Fever, dyspepsia	28	Surgical
	51	M	Small intestine	Abdominal pain	63	Surgical
Kim et al4	52	M	Stomach	Dyspepsia	34	No treatment
	63	M	Stomach	Dyspepsia	23	No treatment
	51	M	Duodenum	Dyspepsia	40	No treatment
	48	M	CBD	Jaundice	31	Percutaneous removal
Ha et al5	48	M	Stomach	No specific symptoms	6	Surgical
Hung et al6	54	M	Duodenum	Acid regurgitation	6	Surgical
Park et al7	36	M	Duodenum	No specific symptoms	36	Surgical
Sultan et al8	59	M	Duodenum	No specific symptoms	59	No treatment
Koc et al9	47	M	Duodenum	Fever, abdominal pain	18	Surgical
	53	M	Duodenum	Fever	14	Surgical
	64	M	Duodenum	Fever	18	Surgical
	50	M	Stomach	Fever, abdominal pain	14	Endoscopic
	57	M	Duodenum	Fever, rigors	16	Endoscopic
	50	M	Duodenum	Fever, abdominal pain	17	Endoscopic
	39	F	Stomach	Fever, rigors	23	Endoscopic
	64	M	Duodenum	Fever, abdominal pain	18	Surgical
	51	M	Duodenum	Fever, abdominal pain	19	Surgical
	49	M	Stomach	Fever, rigors	14	Surgical
Present report	56	M	Duodenum	Dyspepsia	38	Endoscopic
	65	M	Colon	Hematochezia	69	Endoscopic
	65	F	Duodenum	No specific symptoms	112	Endoscopic

ePTFE, expanded polytetrafluoroethylene; LDLT, living donor liver transplantation; M, male; F, female; CBD, common bile duct; ERBD, endoscopic retrograde biliary drainage; PTBD, percutaneous biliary drainage..

A previous study reported complications associated with ePTFE in 4.7% of cases (17 of 360 patients).³ These complications included three instances of infection and 14 cases of graft migration, with the migration sites being the common bile duct in three cases, the stomach in one case, the duodenum in five cases, and the jejunum in five cases. Eight patients required intervention, which included hepatic segmentectomy, hepaticojejunostomy, percutaneous drainage insertion, and biliary interventions such as endoscopic retrograde biliary drainage and percutaneous transhepatic biliary drainage (PTBD). Another study reported a complication rate of 1.52% (4 of 262 patients).² One patient experienced complete thrombosis of the graft at 24 months post-transplantation and subsequently died from sepsis and multiorgan failure. Three patients experienced graft migration into the second portion of the duodenum and required surgical exploration and removal of the ePTFE graft. One of these patients died from overwhelming sepsis.

Researchers have hypothesized that thrombotic occlusion of the ePTFE vascular graft exacerbates inflammation around the graft.^2,3 This inflammation may promote the adhesion of the ePTFE graft to adjacent organs, potentially leading to graft migration.^2,3 Since this process is gradual, the time between LDLT and the diagnosis of ePTFE graft migration has varied widely, ranging from 5 to 128 months in previous reports. In our case series, patients were diagnosed with ePTFE graft migration at 38, 69, and 112 months following LDLT, respectively.

Most of the 26 patients from previous reports exhibited significant symptoms such as fever and abdominal pain, with some presenting with infection and sepsis. Migration sites included the stomach (6 cases), duodenum (15 cases), jejunum (1 case), and common bile duct (4 cases). Many patients required intervention, including surgery in 14 cases. However, our case series reports a patient with minor symptoms whose stent migrated into the duodenum and transverse colon, which is highly unusual. All migrated stents were removed endoscopically. A management protocol for ePTFE graft migration into adjacent hollow viscera in LDLT recipients has not yet been established. Our experience suggests that patients should be managed according to their clinical situation, as determined by the attending physician.

Risk factors for stent migration include repeated postoperative biliary interventions, such as PTBD and endoscopic procedures, which can modify the shape and position of the ePTFE graft.^3,4 The second patient in our study had undergone multiple PTBD insertions to manage accompanied biliary stricture.

All three of our patients were found to have occlusion of ePTFE grafts due to thrombosis several months after LDLT, as seen on follow-up computed tomography (Fig. 5). We believe that careful attention must be paid to the potential for vascular stent migration in LDLT recipients following stent occlusion, particularly in those with a history of repeated postoperative biliary interventions.

Figure 5. Abdominal computed tomography images for the first case. (A) Seven days after living donor liver transplantation (LDLT), the expanded polytetrafluoroethylene (ePTFE) graft (red arrow) remains patent. (B) Six months after LDLT, the ePTFE graft (red arrow) appears occluded due to thrombosis.

In summary, we encountered migrated ePTFE grafts as foreign bodies during endoscopy, which was removed endoscopically without any serious complications. The third case demonstrates the fortunate occurrence of a sealed-off perforation of the GI tract, with spontaneous closure of the fistula tract due to the healing of the bowel wall, following the prolonged migration of an artificial vascular graft.

None.

The data that support the findings of this study are available from the corresponding author upon reasonable request.

No potential conflict of interest relevant to this article was reported.