Safety and efficacy of Kaffes intraductal self-expanding metal stents in the management of post-liver transplant anastomotic strictures

Table 1 Patient demographics

Demographic data of patients	Stent indwelling time
	3 months	6 months
Median age at the time of Kaffes stent insertion, yr (IQR, yr)	57 (48-64)	61 (53-69)
Gender, n (%)
Male	20 (60.6)	19 (57.6)
Female	13 (39.4)	14 (42.4)
Transplant indication, n (%)1
Hepatoma	8 (14.3)	9 (16.1)
Non-alcoholic steatohepatitis	9 (16.1)	5 (8.9)
Alcoholic cirrhosis	6 (10.7)	7 (12.5)
Hepatitis C	8 (14.3)	7 (12.5)
Hepatitis B	4 (7.1)	1 (1.8)
Autoimmune hepatitis	3 (5.4)	6 (10.7)
Cryptogenic cirrhosis	6 (10.7)	3 (5.4)
Acute liver failure	2 (3.6)	3 (5.4)
Primary biliary cirrhosis	2 (3.6)	3 (5.4)
Primary sclerosing cholangitis	2 (3.6)	3 (5.4)
Polycystic liver	2 (3.6)	3 (5.4)
Alpha 1 antitrypsin deficiency	2 (3.6)	3 (5.4)
Other	2 (3.6)	3 (5.4)
Graft size, n (%)
Complete liver graft	31 (93.9)	31 (93.9)
Partial liver graft	2 (6.1)	2 (6.1)
Biliary anastomosis anatomy, n (%)
End to end	33 (100.0)	31 (93.9)
End to side	0 (0.0)	2 (6.1)
Transplant complications, n (%)
History of rejection	19 (63.3)	12 (36.4)
History of bile leak	5 (16.7)	6 (18.2)
History of hepatic artery thrombosis	1 (3.3)	2 (6.1)
History of previous anastomotic stricture	28 (93.3)	31 (93.9)
Time between transplant and Kaffes insertion, wk (IQR, wk)	79 (33-149)	80 (18-240)

¹30 Liver transplant recipients had more than 1 indication for transplant.

IQR: Interquartile range.

Table 2 Endoscopic retrograde cholangiopancreatography details

ERCP characteristics	3 months	6 months
Indication for ERCP, n (%)1
Stricture	31 (93.9)	31 (93.9)
Choledocolithiasis	3 (9.1)	5 (15.2)
Cholangitis	2 (6.1)	8 (24.2)
Other2	12 (36.4)	6 (18.2)
ERCP setting, n (%)
Inpatient	11 (33.3)	12 (36.4)
Outpatient	22 (66.6)	21 (63.6)
Imaging prior to ERCP, n (%)
Ultrasound	13 (39.4)	16 (48.5)
CT abdomen	15 (45.5)	18 (54.5)
Magnetic resonance cholangiopancreatography	19 (57.6)	22 (66.7)
At least one of the above modalities	28 (84.8)	29 (87.9)
Technical details, n (%)
Sphincterotomy	2 (6.1)	2 (6.1)
Dilatation	8 (24.2)	8 (24.2)
Previous stent in situ, n (%)
Nil	15 (45.5)	20 (60.6)
Plastic	18 (54.5)	13 (39.4)
Indication for Kaffes, n (%)
New stricture	9 (27.3)	16 (48.5)
Persistent stricture, failed plastic stent program	20 (60.6)	15 (45.5)
Persistent stricture, failed metal stent program	0 (0.0)	1 (3.0)
Persistent stricture, failed combination stents	1 (3.3)	0 (0.0)
Migration of previous stent	0 (0.0)	0 (0.0)
Stricture recurrence	3 (9.1)	1 (3.0)

¹Note a portion of patients had multiple indications for endoscopic retrograde cholangiopancreatography (ERCP).

²Other indications for ERCP include: Deranged liver function tests, abdominal pain and bile leak follow up.

ERCP: Endoscopic retrograde cholangiopancreatography; CT: Computed tomography.

Table 3 Post-endoscopic retrograde cholangiopancreatography complications

Post-ERCP complications	3 months	6 months	P value
Any complication, n (%)	3 (6.1)	3 (9.1)	0.40
Pancreatitis, n (%)
Episodes	0 (0.0)	0 (0.0)	1.00
During Kaffes insertion
Prophylactic rectal indomethacin	2 (6.1)	4 (12.1)	0.40
Pancreatic duct cannulation	1 (3.0)	1 (3.0)	1.00
Pancreatic duct stent insertion1	1 (3.0)	0 (0.0)	0.32
Cholangitis, n (%)
Episodes	0 (0.0)	1 (3.0)	0.32
Prophylactic antibiotics at Kaffes insertion	30 (90.9)	29 (87.9)	0.69
Piperacillin/Tazobactam	20 (60.6)	25 (75.8)
Ciprofloxacin	1 (3.0)	0 (0.0)
Ceftriaxone	8 (24.2)	0 (0.0)
Other	1 (3.1)	4 (12.1)
Bleeding2	1 (3.3)	0 (0.0)	1.00
Admission3	2 (6.7)	3 (9.1)	0.31
Stent migration	1 (3.3)	0 (0.0)	0.29

¹Pancreatic duct stent inserted for same patient who had inadvertent duct cannulation.

²Bleeding due to gastric ulcer, unrelated to endoscopic retrograde cholangiopancreatography (ERCP) procedure.

³Case with bleeding was included even though unrelated to ERCP procedure.

ERCP: Endoscopic retrograde cholangiopancreatography.

Table 4 Stricture recurrence data based on Kaffes indwelling time, regardless of stent course duration

Stricture outcomes	3 months	6 months	P value
Stricture resolution on stent extraction, n (%)	30 (96.8)	30 (93.8)	0.72
Stricture recurrence, n (%)	14 (42.4)	3 (9.1)	0.01a
Median days to recurrence since stent removal, d (IQR, d)	273 (73-1192)	431 (7-617)

^aStricture recurrence was significantly less when Kaffes was inserted for 6 months.

IQR: Interquartile ranges.

Table 5 Stent efficacy based on stent course duration (all stent courses involving Kaffes insertion, regardless of Kaffes indwelling time)

Stricture outcomes	≤ 120 d	> 120 d	P value
n	7	56
Median duration of stent course, d (IQR, d)	95 (90-116)	196 (176-296)
Stricture resolution on Kaffes removal, n (%)	7 (100.0)	50 (89.3)	0.66
Recurrence
n (%)	5 (71.4)	12 (21.4)	0.03a
Median days to recurrence (IQR)	248 (104–812)	368 (259-1084)	0.33

^aStricture recurrence was significantly less when Kaffes was inserted for > 120 d.

IQR: Interquartile ranges.

Table 6 Stent efficacy (stent courses where Kaffes stent was the final stent)

Stricture outcomes	≤ 120 d	> 120 d	P value
n	7	50
Median duration of stent course, d (IQR, d)	95 (90-116)	193 (178-281)
Stricture resolution at end of course, n (%)	7 (100.0)	50 (100.0)	1.00
Recurrence
n (%)	5 (71.4)	9 (18.0)	0.02a
Median days to recurrence (IQR)	248 (104-812)	431 (264-1522)	0.24

^aStricture recurrence was significantly less in stent courses where Kaffes stent was the final stent and left indwelling for >120 d.

IQR: Interquartile ranges.

Table 7 Stent efficacy (stent courses where Kaffes stent was the only stent used)

Stricture outcomes	≤ 120 d	> 120 d	P value
n	7	21
Median duration of stent course, d (IQR, d)	95 (90-116)	183 (167-193)
Stricture resolution on Kaffes removal, n (%)	7 (100.0)	20 (95.0)	1.00
Recurrence
n (%)	5 (71.0)	2 (10.0)	0.01a
Median days to recurrence (IQR)	248 (27-812)	1139 (785-1493)	0.19

^aStricture recurrence was significantly less when Kaffes stent was used upfront and left indwelling for >120 days.

IQR: Interquartile ranges.

Table 8 Intraductal fully covered self-expanding metal stents studies (18, 19, 22, 26, 27, 28)

Ref.	Sissingh et al[22], 2023	Warner et al[18], 2020	Martins et al[27], 2018	Tal et al[26], 2017	Cote et al[28], 2016	Kaffes et al[19], 2014
n	80	62	59	48	73	20
FCSEMS removal protocol, months	6	3	6	4-6	6-12	3
Median stent indwelling time, months	NA	10	5	6	6	4
Stricture resolution (%)	93	96	83	100	89	100
Stricture recurrence (%)	33	25	32	21	15	30
Migration rate (%)	16	NA	10	21	45	0
Acute pancreatitis (%)	7	5	13	NA	6	NA
Cholangitis rate (%)	7	4	2	NA	3	10
Bile duct perforation (%)	0	2	NA	NA	NA	NA

FCSEMS: Fully covered self-expanding metal stents; NA: Not available.