Enlarging vascular stents after pediatric liver transplantation

Balloon angioplasty versus stent placement for the treatment of portal vein stenosis in children: a single center experience

PURPOSE

To evaluate the safety and efficacy of percutaneous interventional treatment of portal vein stenosis in children.

MATERIAL AND METHODS

A retrospective analysis of all interventional treatments for portal vein stenosis in pediatric patients at a single institution from 2010 to 2021 was conducted. Platelet count, spleen size and portal vein flow velocity were assessed during the follow-up period. Primary and primary assisted patency time were determined.

RESULTS

A total of ten children (median age 28.5 months, interquartile range (IQR): 2.75-52.5 months) with portal vein stenosis after Mesorex-Shunt (n = 4), liver transplantation (n = 3) and other etiologies (n = 3) underwent 15 interventional procedures. There were five reinterventions and one discontinued intervention. The technical success rate was 93.3% (14/15) and clinical success of treated patients was 100% (14/14). Median follow-up was 18 months (IQR: 13.5-81 months). The median primary patency time for stent placement was 70 months (IQR: 13.5-127.25 months). For balloon angioplasty, the median primary patency time was 9 months (IQR 7.25-11.5 months), while the median assisted primary patency time was 14 months (IQR: 12 to 15 months). Platelet count, spleen size and portal vein flow velocity reliably corresponded to recurrence of portal vein stenosis in asymptomatic patients during follow-up.

CONCLUSION

Interventional treatment is a safe and efficient method to treat portal vein stenosis with long patency times, regardless of etiology. Primary stent placement shows a higher primary patency time than balloon angioplasty. Implementation of stent placement as the primary interventional method may improve patency times and reduce the need for repeat reinterventions in pediatric patients.

Endovascular treatment of symptomatic hepatic venous outflow obstruction post major liver resection

PURPOSE

To evaluate efficacy, safety, and outcomes of endovascular treatment of hepatic vein stenosis post major liver resection.

METHODS

A retrospective data analysis was performed including all interventional treatments of hepatic vein stenosis post major liver resection since 2010. Post procedural course and clinical parameters including amount of ascites accumulation and relevant laboratory values were assessed during the follow-up period. Primary and primary assisted hepatic venous patency time were calculated.

RESULTS

Twelve patients (median age 55.5, IQR 49.75 to 61.5 years) undergoing a total of 16 interventions were included. Interventions were primary stent placement (n = 3), primary balloon angioplasty (n = 8), three re-interventions and two aborted interventions (no significant pressure gradient). Technical success was 100% (16/16). Permanent reduction and / or complete resolution of ascites was achieved in 72% (8/11). Laboratory parameters related to liver function did not show significant improvement after intervention. Median follow-up period was 6 months (IQR: 1.5 to 18 months). The median primary patency time for patients with balloon angioplasty was 11 months (IQR: 1.375 to 22.25 months) and assisted patency time was 13.25 months (IQR: 4.5 to 22.25 months). The median primary patency time for patients with angioplasty and stent placement was 1 months (IQR: 1.0 to 1.5 months) and assisted patency time was 2.0 months (IQR: 1.5 to 2.5months).

CONCLUSION

An endovascular approach for the treatment of hepatic venous stenosis post major liver resection is safe and efficient to reduce and / or resolve refractory ascites. However, liver function parameters seem not to be improved by the procedure. Stent placement can be a reasonable option in patients with significant residual stenotic disease post angioplasty.

Incidence of superficial left hepatic vein and its usability for graft hepatic vein venoplasty in pediatric liver transplantation

BACKGROUNDS

The anatomy of the left hepatic vein (LHV) is variable; thus, it should be considered for graft hepatic vein (GHV) venoplasty for left lateral section (LLS) and left liver grafts. This study assessed the incidence of superficial LHV (sLHV) branches according to LHV anatomy and its usability for GHV venoplasty in pediatric liver transplantation (LT).

METHODS

This study consisted of three parts: (1) anatomical classification of LHV variations and the incidence of sLHV branches; (2) morphometric simulative analysis of GHV reconstruction and (3) clinical application based on LHV anatomy.

RESULTS

The LHV anatomy of 248 potential LLS graft donors was classified into four types according to the number and location of GHV openings: one single opening (type 1; n = 186 [75.0%]), two large openings (type 2; n = 35 [14.1%]), one large and one small adjacent opening (type 3; n = 14 [5.6%]), and two large widely-separated openings (type 4; n = 13 [5.2%]). An sLHV branch was identified in 87 of 248 (35.1%) donor livers. Morphometric analysis of simulative GHV venoplasty with an sLHV branch increased GHV diameters by 30% in type 1 LLS grafts and 20% in type 2/3 LLS grafts. An analysis of 50 consecutive patients who underwent pediatric LT showed that the 2-year rates of GHV obstruction were 2.0% with LLS grafts and 0% with left liver grafts.

CONCLUSIONS

The GHV orifice can be enlarged through LHV anatomy-based unification venoplasty. Unification venoplasty with an sLHV branch provided sufficient enlargement of the GHV orifice.

Advanced preoperative three-dimensional planning decreases the surgical complications of using large-for-size grafts in pediatric living donor liver transplantation

BACKGROUND

Using "large-for-size" liver graft, graft-to-recipient weight ratio (GRWR) ≥4%, has been debated in pediatric liver transplantation due to possible graft compartment after abdomen closure. Meticulous preoperative evaluation with three-dimensional (3D) techniques may prevent these problems. This study compared the safety of large-for-size grafts in pediatric living donor liver transplantation (PLDLT) during the eras with or without 3D planning.

METHODS

We defined the 3D era was after November 2017 due to our first implication of 3D printing for surgical planning and subsequently developing a 3D simulation implanting model. From November 2004 to July 2021, we enrolled 30 PLDLT patients with body weight (BW) < 10 kg and categorized them into conventional group: GRWR ≥4% before the 3D era (n = 9), 3D group: GRWR ≥4% in the 3D era (n = 8), and control group: GRWR <4% (n = 13). We followed and compared their clinical outcomes.

RESULTS

The 3D group had the lowest BW and the highest graft volume reduction rate, with all receiving modified left lateral segments (LLS), such as reduced LLS (n = 2), hyperreduced LLS (n = 5), and segment 2 monosegment (n = 1). Overall postoperative complications were similar in conventional and control groups but significantly lower in the 3D group (OR 0.06, 95% CI 0.006-0.70, p = 0.025). However, all groups had similar graft and patient survival at 1, 2, and 4 years.

CONCLUSION

Advanced preoperative 3D planning can decrease post-transplant complications and increase the safety of large-for-size grafts in PLDLT.

LEVEL OF EVIDENCE

Type of study: Retrospective comparative study; Evidence level: Level III.

Usability of intraoperative cine-portogram during liver transplantation in young pediatric patients with biliary atresia

BACKGROUND

Pediatric patients with biliary atresia (BA) often present liver cirrhosis-associated portal hypertension and portal vein (PV) hypoplasia. For successful liver transplantation (LT), it is essential to maintain sufficient PV inflow through stenosis-free PV reconstruction with effective ligation of collateral veins. The aim of this study was to assess the clinical usability of intraoperative cine-portogram (IOCP) in young pediatric patients who underwent LT for BA.

METHODS

Medical records of pediatric patients younger than 10 years who underwent primary LT for BA from 2018 to 2020 were reviewed.

RESULTS

A total of 31 patients had undergone Kasai portoenterostomy soon after birth. Their median ages at Kasai portoenterostomy and LT were 1 and 11 months, respectively. Types of LT were living-donor LT in 13, deceased-donor split LT in 15, and deceased-donor whole LT in three patients. PV interposition using an iliac vein homograft was performed in 28 patients receiving partial liver grafts. Side-to-side PV unification venoplasty was performed in three patients undergoing whole LT. All patients underwent ligation of collateral veins. IOCP was performed in 6 (19.4%) patients. Four showed no or faint residual venous collaterals. Collateral vein embolization and endovascular stenting were performed in one patient each. PV insufficiency-free survival rate was 100% at 1 year and 93.8% at 3 years. All patients are currently alive with a median follow-up period of 23 months.

CONCLUSIONS

Intraoperative cine-portogram can be a useful method for identification and embolization of residual portosystemic collateral veins in young pediatric patients who undergo LT for biliary atresia.

Percutaneous transhepatic interventional therapy of portal vein stenosis in paediatric liver transplantation: A systematic review of efficacy and safety

PURPOSE OF THE SYSTEMATIC REVIEW

To determine the efficacy and safety of percutaneous trans-hepatic balloon and/or stent angioplasty (PTA) in the management of portal vein (PV) stenosis following paediatric liver transplantation.

METHODS

Articles were included from a systematic search of Medline, Embase, Cochrane CENTRAL, ClinicalTrials.gov and International Clinical Trials Registry from inception to the 29th of August 2020.

RESULTS

There were 213 paediatric liver recipients who underwent PTA for PV stenosis in 19 included studies published between 1991 and 2019. Balloon angioplasty was the initial treatment in the majority (n = 153). Primary stent placement (n = 34) was performed for elastic recoil, intimal tears and PV kinks and rescue stent placement (n = 14) for recurrent PV stenosis following primary balloon angioplasty. The technical success was 97.6%-100% overall, 97.6%-100% for balloon-angioplasty-only and 100% for primary stenting. The clinical success was 50%-100% overall, 50%-100% for balloon-angioplasty-only and 100% for primary stenting. Long-term PV patency was 50%-100% overall, 37.5%-100% for balloon-angioplasty-only and 100% for primary stenting. Primary balloon angioplasty was successful in 78% of the cases. Of the recurrent PV stenoses, 9% resolved with stent placement and one required a meso-Rex shunt. There was one re-transplantation without stenting. The complication rate was 2.6% for balloon-angioplasty-only (bleeding, liver abscess, 2 PV thromboses) and 5.9% for primary stenting (bleeding, stent-fracture). There was no procedure-related mortality.

CONCLUSION

Percutaneous transhepatic balloon angioplasty may be the initial management of portal vein stenosis in paediatric liver recipients. Stent placement may be a primary option in selected cases and a reliable rescue option for recurrent portal vein stenosis following balloon-angioplasty-only.

Funneling venoplasty for anomalous graft left hepatic vein in living donor liver transplantation using a split left lateral section graft for an infant patient

The left lateral section (LLS) can have an unusual variant left hepatic vein (LHV) anatomy. We present a case of customized funneling venoplasty of the graft LHV in a 22-month-old girl diagnosed with ornithine transcarbamylase deficiency undergoing deceased donor liver transplantation (LT) using a split LLS graft. The split LLS graft weighed 350 g, yielding a graft-to-recipient weight ratio of 3.2%. Notably, the graft LHV opening was located at the graft liver cut surface, which was only 1 cm in size and 2 cm away from the cephalad apex of the LLS graft. Since such a variant location of the small LHV opening was unsuitable for direct anastomosis, we performed a funneling venoplasty using an inferior vena cava fragment homograft obtained from the same donor. The graft implantation was performed according to standard procedures of infant split LT. Follow-up imaging studies showed no vascular complications. The patient recovered uneventfully from the LT operation. She had normal blood test findings, including normal ammonia level. She has been doing well for 6 months after the transplantation. In conclusion, our surgical technique using a funneling venoplasty enabled successful reconstruction of the anomalous graft LHV. Our results suggest that individualized reconstruction techniques should be applied to infant patients undergoing LT using a LLS graft with variant types of graft LHV anatomy.

Outflow vein venoplasty of left lateral section graft for living donor liver transplantation in infant recipients

The orifice size of the LHV trunk in LLS grafts is often too small for direct anastomosis. Several methods were developed to enlarge the graft and recipient hepatic vein orifices. This study described our surgical techniques to secure hepatic vein reconstruction in infant recipients and analyzed the patency outcomes. Twelve infants undergoing pediatric LDLT were selected during 2-year study period between January 2018 and December 2019. Surgical techniques and vascular complications of graft hepatic vein outflow were analyzed. The mean recipient age was 12.5 ± 4.5 months; mean body weight was 9.4 ± 1.0 Kg; and mean graft-recipient weight ratio was 2.8 ± 0.6%. Primary diseases were biliary atresia in six patients, metabolic diseases in two, hepatoblastoma in two, and acute liver failure in two. Eight LLS grafts were recovered through an open method, and four LLS grafts were recovered through a laparoscopic method. A small superficial LHV branch was present in five of 12 LLS grafts, which was opened to widen the graft hepatic vein orifice. Incision-and-patch venoplasty was performed in 10, unification venoplasty in 1 and no venoplasty in 1. All four LLS grafts recovered through a laparoscopic approach required circumferential vein patch because of very short hepatic vein stump. No patient experienced graft hepatic vein-associated vascular complications during the follow-up period of 19.3 ± 9.3 months. Our surgical techniques with incision-and-patch venoplasty for LLS grafts is beneficial to reduce the risk of hepatic vein outflow obstruction in recipients receiving LLS grafts.

Third retransplantation using a whole liver graft for late graft failure from hepatic vein stent stenosis in a pediatric patient who underwent split liver retransplantation

We present a case of third retransplantation using a whole liver graft in a 13-year-old girl who suffered graft failure and hepatopulmonary syndrome following split liver retransplantation with endovascular stenting of the hepatic and portal veins as an infant. She was diagnosed with biliary atresia-polysplenia syndrome, and thus underwent living donor liver transplantation from her mother at 9 months of age. The first liver graft failed due to stenosis of the portal vein. She underwent the second liver transplantation with a split left lateral section graft. Endovascular stenting was performed to the portal vein stenosis 2 months and hepatic vein stenosis 9 months after transplantation. During the next 9 years, 11 sessions of balloon angioplasty for hepatic vein stent stenosis were performed. Ten years after the second transplantation, she underwent third transplantation using a whole liver graft recovered from a 12-year-old-girl. The double inferior vena cava technique was used for outflow vein reconstruction. The graft portal vein was anastomosed with the stent-containing portal vein stump because it was not possible to remove the stent and the inner diameter of the portal vein stent was large enough. An aorto-hepatic jump graft was used for arterial reconstruction. The patient recovered slowly and is doing well for 6 months posttransplant. In conclusion, because stenting of the hepatic vein or portal vein can induce graft failure leading to late retransplantation, we emphasize secure vascular reconstruction to prevent endovascular stenting during LT in infants.

Pediatric split liver transplantation for congenital factor X deficiency: first 10-year follow-up of a case with portal vein stenting

Congenital factor X (FX) deficiency is a rare autosomal-recessive disease that induces bleeding disorder. Herein, we present the 10-year posttransplant course of a pediatric patient who underwent liver transplantation (LT) with portal vein (PV) stenting for correction of severe congenital FX deficiency, with focus on long-term maintenance of coagulation function and patency of PV stenting. A 17-month-old infant with recurrent hemorrhagic episodes due to FX deficiency underwent split LT using a left lateral section graft. The graft-recipient weight ratio was 2.2%. The graft implantation procedures were performed by following the standard pediatric split LT procedure. Nevertheless, a wall stent was inserted due to PV anastomotic stenosis on posttransplant day 1. Graft function recovered slowly because of partial parenchyma infarct, and the patient was discharged at 46 days after LT operation. The FX activity started to increase soon after LT and gradually normalized; the coagulation profiles have been maintained well for the past 10 years. The patient has been doing well for the past 10 years after LT without any episodes of abnormal bleeding. Due to the risk of vascular complications owed to PV stenting, life-long follow-up is mandatory with special attention until attainment of complete physical growth to adolescent and adulthood.

Safety and Efficacy of Endovascular Treatment of Portal Vein Stenosis in Liver Transplant Recipients: A Systematic Review

PURPOSE

To evaluate the efficacy of Angioplasty and Stent Placement for the treatment of Portal Vein Stenosis in Liver Transplant Recipients by performing a systematic review.

MATERIALS AND METHODS

The PubMed Database was extensively searched for articles describing Portal Vein Stenosis (PVS) as a complication in Liver Transplant (LT) patients. The initial database search yielded 488 unique records published in the PubMed Database, 19 of which were deemed to meet the inclusion criteria. Outcomes were separated into 2 groups (Group A included patients with primary angioplasty, Group B included patients with primary stent placement), and further subdivided into Adult and Pediatric populations.

RESULTS

Group A included a total of 282 LT patients with portal vein stenosis. The population was predominantly pediatric (n = 243). Group B included a total of 111 LT patients with portal vein stenosis. This population was predominantly adult (n = 66). Technical success was significantly higher in both Group B pediatric (100%) and adults (97%) compared to Group A (69.5%) and (66.7%) respectively. Re-stenosis rates were significantly lower in Group B pediatric group compared to Group A (2.3% vs 29.7%, χ² = 13.9; p < 0.001). Overall major (3.1%) and minor complications rates (1.5%) were low.

CONCLUSION

Primary stent placement appears to have higher technical success in both populations and lower re-stenosis rates for treatment of PVS in pediatric populations.

Portal vein reconstruction using side-to-side unification technique for infant-to-infant deceased donor whole liver transplantation

Backgrounds/Aims

Infant-to-infant whole liver transplantation (I2I-WLT) has been rarely performed in Korea. We analyze clinical sequences of our 7 cases of I2I-WLT and present evolution of surgical techniques to prevent PV stenosis.

Methods

A total of 7 cases of I2I-WLT were performed at our institution during last 13 years, which represented 0.1% of our LT volume. Patient perioperative profiles and clinical sequences were analyzed with focusing on portal vein (PV) complications.

Results

Donor ages were 6-17 months and graft weights were 140-525 g. Recipient ages were 7-16 months and body weights were 6-10.1 kg and Primary diagnoses were biliary atresia in 6 and progressive familial intrahepatic cholestasis in 1. The first case underwent PV stenting 2 months after I2I-WLT, and underwent retransplantation 6 years later. The second case underwent intraoperative PV stenting, but died 32 days later. The third case underwent repeated PV dilatation. The fourth, fifth and seventh cases experienced no surgical complications, and PV reconstruction was performed using a side-to-side unification venoplasty technique. The sixth case had poor development of the PV system, so customized PV venoplasty was performed, but PV occlusion requiring PV stenting occurred. Early retransplantation was performed, but scanty PV flow was detected despite no obvious PV stenosis, resulting in graft failure. Serious PV complications developed in 4, but none experienced after adoption of side-to-side unification venoplasty.

Conclusions

As PV size in infant donors and recipients is very small, PV reconstruction in I2I-WLT requires specialized surgical techniques of side-to-side unification venoplasty.

Graft outflow vein venoplasty for a laparoscopically harvested left lateral section graft in pediatric living donor liver transplantation

Laparoscopically harvested left lateral section (LLS) grafts have drawbacks regarding the size of the graft left hepatic vein (LHV) orifice although they have the merit of cosmetics concerning the donor’s wound. We present a case of pediatric living donor liver transplantation (LDLT) using a laparoscopically harvested LLS graft and describe the refined surgical techniques for graft LHV venoplasty with a circumferential vein patch. The patient was a 46-month-old boy with marked growth retardation who was diagnosed with progressive familial intrahepatic cholestasis type 2. The donor was his 25-year-old mother. The LLS graft weighed 285 g. A circumferential patch of external iliac vein homograft was attached to the graft LHV orifice after incisions were made at the medial wall of the LHV trunk and superficial LHV branch, which made the graft LHV orifice much larger. The recipient’s hepatic vein orifice was also enlarged by unifying the three hepatic vein orifices. Other surgical procedures followed the standard LDLT operation. This patient recovered uneventfully and has been doing well for 1 year. In conclusion, our incision-and-patch venoplasty to enlarge the graft outflow vein orifice was beneficial for reducing the risk of hepatic vein outflow obstruction in LDLT using a laparoscopically harvested LLS graft.

Side-to-side portal vein reconstruction for infant-to-infant deceased donor whole liver transplantation: Report of 2 cases with video

Infant-to-infant whole liver transplantation (I2I-WLT) has been rarely performed in Korea. Unlike living donor liver transplantation or split liver transplantation, the donor graft portal vein (PV) in I2I-WLT is very small in diameter, so risk of PV complications increases significantly. We present two cases of I2I-WLT with application of side-to-side unification venoplasty for secure PV reconstruction. The first case recipient was a 10-month-old female baby who weighed 6.0 kg. She was diagnosed with progressive familial intrahepatic cholestasis. The deceased donor was a 12-month-old boy. The graft weight was 245 g, so the graft-recipient weight ratio (GRWR) was 4.1%. PV was reconstructed using side-to-side unification venoplasty. The function of graft liver recovered uneventfully and there was no evidence of PV complications. She is currently doing well for 4 years. The second case recipient was a 10-month-old female baby who weighed 8.8 kg. She had also undergone Kasai operation for biliary atresia. GRWR was 6.0%. Because the graft liver was much larger than the native liver, we designed the length of the extrahepatic PV more redundant than the precedent cases to avoid extrinsic compression by the large-sized caudate lobe. The PV was reconstructed using side-to-side unification venoplasty. The function of the graft liver recovered uneventfully. There was no evidence of PV complications. She is currently doing well for 2 years. As the PV size in infant donors and recipients is very small, PV reconstruction in I2I-WLT requires specialized surgical techniques of side-to-side unification venoplasty. Three supplementary video clips are provided.

Graft outflow vein unification venoplasty with superficial left hepatic vein branch in pediatric living donor liver transplantation using a left lateral section graft

Orifice size of the left hepatic vein trunk (LHV) in left lateral segment (LLS) grafts is often too small to perform direct anastomosis. A small superficial branch of LHV is encountered in approximately 30% of LLS grafts. Unification venoplasty of the LHV trunk and its superficial vein branch makes the orifice size of LLS outflow vein larger than the original size. We present refined surgical techniques for LHV unification venoplasty with a superficial LHV branch. The patient was a 5-month-old 9 kg-weighing girl with biliary atresia. Her general condition deteriorated, but there was low possibility of deceased donor liver allocation, thus living donor liver transplantation was performed using her mother's LLS. The graft hepatic vein was widened through unification venoplasty of LHV and its superficial branch. Recipient hepatic vein orifice was widened through unification of three hepatic veins. The graft and recipient hepatic vein orifices were well matched in size, and they were anastomosed with 5-0 continuous sutures. The portal vein was reconstructed with interposition of cold-preserved external iliac vein homograft. The graft left hepatic artery was reconstructed using the recipient right hepatic artery and hepaticojejunostomy was performed. This patient recovered uneventfully and is doing well for 3 months to date. The unification venoplasty with LHV trunk and its superficial vein branch makes the size of LLS outflow vein definitely larger than the original size, thus it can be a useful technical option to reduce the risk of hepatic vein outflow obstruction in pediatric liver transplantation using a LLS graft.