Clinical outcome and neurological development of patients with biliary atresia associated with a bleeding tendency: a single institution experience.

PURPOSE: We compared the clinical features of patients with biliary atresia (BA) associated with a bleeding tendency (BT) at the time of the diagnosis with those of patients without a bleeding tendency (NBT). METHODS: The patients' background characteristics, age in days at the first visit, Kasai portoenterostomy (KPE), and postoperative course were retrospectively analyzed. RESULTS: Nine of the 93 BA patients (9.7%) showed a BT, including 7 with intracranial hemorrhaging (ICH), 1 with gastrointestinal bleeding, and 1 with a prothrombin time (PT) of 0%. The age at the first visit was 62 ± 12 days old for BT patients and 53 ± 27 days old for NBT patients (p = 0.4); the age at KPE was 77 ± 9 days old for BT patients and 65 ± 24 days old for NBT patients (p = 0.2); the time from the first visit to surgery was 13 ± 7 days for BT patients and 11 ± 10 days for NBT patients (p = 0.5); and the native liver survival rate was 56% for BT patients and 58% for NBT patients (p = 1), with no significant difference in any of the parameters. The neurological outcomes of survivors of ICH were favorable. CONCLUSIONS: Appropriate BT correction allowed early KPE even after ICH, resulting in native liver survival rates comparable to those of NBT patients without significant neurological complications.

Impact of hepatocyte growth factor on the colonic morphology and gut microbiome in short bowel syndrome rat model.

PURPOSE: This study aimed to investigate the impact of hepatocyte growth factor (HGF) on colonic morphology and gut microbiota in a rat model of short bowel syndrome (SBS). METHODS: SD rats underwent jugular vein catheterization for total parenteral nutrition (TPN) and 90% small bowel resection [TPN + SBS (control group) or TPN + SBS + intravenous HGF (0.3 mg/kg/day, HGF group)]. Rats were harvested on day 7. Colonic morphology, gut microflora, tight junction, and Toll-like receptor-4 (TLR4) were evaluated. RESULTS: No significant differences were observed in the colonic morphological assessment. No significant differences were observed in the expression of tight junction-related genes in the proximal colon. However, the claudin-1 expression tended to increase and the claudin-3 expression tended to decrease in the distal colon of the HGF group. The Verrucomicrobiota in the gut microflora of the colon tended to increase in the HGF group. The abundance of most LPS-producing microbiota was lower in the HGF group than in the control group. The gene expression of TLR4 was significantly downregulated in the distal colon of the HGF group. CONCLUSION: HGF may enhance the mucus barrier through the tight junctions or gut microbiome in the distal colon.

Safe and secure laparoscopy-assisted jejunostomy tube placement using a percutaneous loop needle device in an infant.

ABSTRACT: We, herein, report a surgical technique for laparoscopy-assisted jejunostomy tube placement in an infant using a loop needle device to fix the jejunum and abdominal wall. A 3-year-old boy with Down's syndrome underwent nutritional management by gastrostomy due to oral feeding difficulty after radical surgery for congenital duodenal stenosis and following bile duct stenosis. However, intractable gastrostomy site leakage emerged; hence, laparoscopy-assisted gastrostomy takedown and simultaneous laparoscopy-assisted jejunostomy tube placement were planned. After laparoscopy-assisted gastrostomy closure was performed, the jejunum was extracted through the umbilical trocar wound. A jejunostomy tube kit was inserted at the left side of the umbilicus. After tube insertion into the jejunum, the jejunostomy tube was wrapped with four interrupted sutures using the Witzel technique. Suture threads were extracted by percutaneous insertion of a loop needle device, and then, the jejunum was fixed to the abdominal wall. The post-operative course was uneventful. Percutaneous insertion of a loop needle device is useful for fixing a jejunostomy tube to the abdominal wall using the Witzel technique. Our technique is safe, secure and expected to reduce the risk of dislodgement of tube and peritonitis associated with jejunostomy tube placement.

Does protocol miconazole administration improve mortality and morbidity on surgical necrotizing enterocolitis?

PURPOSE: Our previous clinical pilot study reported that miconazole (MCZ) prevented morbidity from surgical necrotizing enterocolitis (NEC). The present study re-investigated this effect in a long-term cohort over 20 years. METHODS: We conducted a retrospective cohort study from April 1998 to March 2020. A total of 1169 extremely low-birth-weight infants (ELBWIs) admitted to our neonatal intensive care unit, including 45 with NEC (3.8%), underwent surgery. Since 2002, protocol MCZ administration for 3 weeks has been applied for neonates born before 26 weeks' gestation or weighing under 1000 g. We compared the background characteristics and clinical outcomes between patients with and without MCZ administration. RESULTS: The morbidity rate decreased after applying the MCZ protocol, but no improvement in mortality was seen. A propensity score-matched analysis indicated that treated patients by MCZ showed a delay in developing surgical NEC by 12 days. The MCZ protocol also helped increase body weight at surgery. Prophylactic MCZ administration did not improve the neurological development of the language-social and postural-motor domains in the surgical NEC patients. But cognitive-adaptive domain caught up by a chronological age of 3 years old. CONCLUSIONS: Revising the protocol to extend the dosing period may improve the outcomes of surgical NEC after the onset.

Association between gastrointestinal perforation and patent ductus arteriosus in extremely-low-birth-weight infants: a retrospective study of our decade-long experience.

PURPOSE: Management of persistently patent ductus arteriosus (PDA) in extremely low-birth-weight infants (ELBWIs) requires attention due to the risk of tissue hypoperfusion. We investigated the association between PDA and gastrointestinal perforation. METHODS: We performed a retrospective chart review from 2012 to 2021. Preterm (≤ 32 weeks) ELBWIs with PDA after birth who developed necrotizing enterocolitis (NEC), focal intestinal perforation (FIP), and idiopathic gastric perforation were included; ELBWIs with congenital heart disease were excluded. Data were analyzed using chi-squared tests with Yates; correction, and Student's t test. RESULTS: Five hundred thirty-five preterm ELBWIs were analyzed, including 20 with NEC, 22 with FIP, and 1 with gastric perforation. In NEC and FIP, the ductus arteriosus remained open in 40% (4/10) and 63.6% (14/22) of cases, respectively, and cyclo-oxygenase inhibitor treatment showed poor efficacy (p = 0.492 and 0.240). The incidence of perforation in NEC (4/9 vs. 6/11, p = 0.653), mortality in NEC (3/4 vs. 3/6, p = 0.895) and FIP (6/14 vs. 3/8, p = 0.838) did not differ according to whether the PDA persisted or resolved. CONCLUSION: The presentation of PDA did not affect the mortality or morbidity of ELBWIs. However, it is essential to consider the possibility of gastrointestinal perforation due to decreased organ blood flow caused by ductal steal.

Predictive factors of bowel resection for midgut volvulus based on an analysis of bi-center experiences in southern Japan.

PURPOSE: Midgut volvulus is an urgent disease often occurring in neonates. This study clarified the clinical features of midgut volvulus and evaluated predictors to avoid bowel resection. METHODS: This bi-center retrospective study enrolled 48 patients who underwent surgery for intestinal malrotation between 2010 and 2022. Patients' background characteristics and preoperative imaging findings were reviewed. RESULTS: Midgut volvulus was recognized in 32 patients (66.7%), and 6 (12.5%) underwent bowel resection. Based on a receiver operating curve analysis of bowel resection, the cut-off value of the body weight at birth and at operation were 1984 g [area under the curve (AUC) 0.75, 95% confidence interval (CI) 0.52-0.99] and 2418 g (AUC 0.70, 95% CI 0.46-0.94), respectively. The cut-off value of intestinal torsion was 540° (AUC 0.76, 95% CI 0.57-0.95), and that of the time from the onset to the diagnosis was 12 h (AUC 0.85, 95% CI 0.72-0.98). For midgut volvulus with an intestinal torsion > 540°, the most sensitive preoperative imaging test was ultrasonography (75%) Patients with bloody stool tended to undergo bowel resection. CONCLUSIONS: Patients with a low body weight and bloody stool should be confirmed to have whirlpool sign by ultrasonography and scheduled for surgery as soon as possible.

Potential mechanisms underlying the effect of hepatocyte growth factor on liver injury in short bowel syndrome model rats.

PURPOSE: The purpose of this study was to investigate the autophagy associated with apoptosis in hepatic damage in the short bowel syndrome rat model. METHODS: SD rats underwent jugular vein catheterization for continuous total parenteral nutrition (TPN) and 90% small bowel resection. Animals were divided into two groups: TPN plus SBS (Control group) or TPN plus SBS plus intravenous administration of HGF (HGF group). On day 7, the rats were harvested, and hepatocellular injury was evaluated. RESULTS: In an SBS rat model, hepatic steatosis and lobular inflammation were histologically suppressed in the HGF group (p < 0.01). The expression of tumor necrosis factor-α in the HGF group tend to be higher than that in the control group (p = 0.13). The gene expression of transforming Growth Factor-ß in the HGF group was suppressed compared to the control group (p < 0.01). HGF treatment may have an antiapoptotic effect via the intrinsic pathway by caspase 9. Protein expressions of Rubicon (p = 0.03) and p62 (p < 0.01) in the HGF group were found to have increased compared to those in the control group. CONCLUSION: The inhibitory effect of HGF on hepatic steatosis remains unclear, and further studies focusing on the mechanisms of fat accumulation are needed.

Using indocyanine green fluorescence in laparoscopic surgery to identify and preserve rare branching of the right hepatic artery in pediatric congenital biliary dilatation.

We describe a laparoscopic surgical technique using indocyanine green (ICG) fluorescence to identify and preserve rare arterial branching associated with pediatric congenital biliary dilatation. Congenital biliary dilatation with pancreaticobiliary maljunction was diagnosed in a 9-year-old girl, who presented with upper abdominal pain. Abdominal enhanced computed tomography (CT) showed that the accessory right hepatic artery (aRHA) branched from the posterior superior pancreaticoduodenal artery (PSPDA) and flowed through the right aspect of the dilated common bile duct (CBD) directly into the right lobe of the liver. We performed laparoscopic dilated biliary duct resection and hepaticojejunostomy, administering ICG intravenously, at a dose of 0.6 mg/kg. The ICG fluorescence overlay mode showed an aRHA running along the right side of the dilated CBD. The aRHA was dissected from the CBD without injury. After finishing the anastomosis, the beating of the aRHA was preserved, confirming that blood flow had been maintained.

Optimal timing of definitive surgery for Hirschsprung's disease to achieve better long-term bowel function.

PURPOSE: Few studies have focused on the operative age for Hirschsprung's disease (HD). We evaluated the optimal timing of surgery in HD patients based on their long-term bowel function. METHODS: HD was diagnosed in 65 pediatric patients in our institute between 1992 and 2018. Twenty-five patients underwent the Soave-Denda procedure (SD) and 40 underwent transanal endorectal pull-through (TA). We divided these patients into two groups: those who underwent surgery at < 6 months of age (younger group) and those who underwent surgery at 6-12 months of age (older group). We assessed bowel function at 5, 7, and 9 years of age. RESULTS: The bowel function of the patients who underwent the SD did not differ significantly between the groups. Similarly, the total bowel-function scores of the patients who underwent TA did not differ between the groups at any age. However, the soiling score at 7 years of age in the older group of patients who underwent TA was significantly lower than that in the younger group (p = 0.02). CONCLUSIONS: Our data suggest that to achieve optimal bowel function, TA should be performed at < 6 months of age.

Retroperitoneal teratomas in children: a single institution experience.

PURPOSE: Retroperitoneal teratomas (RPTs) are rare in infants. We report our experience of treating pediatric patients with RPTs over many years at a single institution, with the aim of developing a safe and secure operative strategy for RPTs in infants. METHODS: We reviewed the medical records of patients who underwent treatment for RPTs in our institution between April, 1984 and December, 2017, to analyze their background and clinical data. The diagnosis of RPT was confirmed histologically in all patients. RESULTS: The subjects of this retrospective analysis were 14 pediatric patients (female, n = 11; male, n = 4), ranging in age from 6 days to 12 years, 11 (73.3%) of whom were under 1 year of age. Complete surgical resection was performed in all patients. The tumor ruptured during surgery in four (26.7%) patients and perioperative vessel injuries occurred in six (40.0%) patients, resulting in nephrectomy in one (6.7%). Three (20.0%) patients suffered unilateral renal dysfunction as a surgical complication. Only one patient received postoperative chemotherapy. All patients were free of disease at the time of writing. CONCLUSION: Perioperative complications are not uncommon during surgery for RPTs, despite their benign nature. Preoperative imaging evaluation is important and operative management may be challenging. Because of the favorable prognosis and the frequency of adverse events in surgery, partial resection or split excision is sometimes unavoidable. Meticulous follow-up for recurrence is required for such patients.

The preoperative lymphocyte ratio and postoperative C-reactive protein are related to the surgical outcome in biliary atresia: an analysis of serial ubiquitous markers of inflammation.

PURPOSE: Various prognostic predictors for biliary atresia (BA) have been identified. This study aimed to evaluate the serial changes in the preoperative and postoperative ubiquitous inflammatory biomarkers and their relationship with the outcomes in patients with BA. PATIENTS AND METHODS: Forty-three BA patients were retrospectively reviewed to investigate serial levels of ubiquitous inflammatory biomarkers, including C-reactive protein (CRP) and lymphocyte ratio, and outcomes. The patients with BA were divided based on their outcomes into two prognostic groups: the native liver survivor group (n = 30) and the survivors with living-donor liver transplant group (n = 13). RESULTS: The area under the receiver operating characteristic (ROC) curve analysis showed that a preoperative lymphocyte ratio of < 61% and CRP value > 0.1 mg/dl predicted a poor outcome. In the ROC curve analysis, the timing of reaching the cut-off value of CRP after Kasai portoenterostomy was postoperative day (POD) 57. The third postoperative week, which was the timing of the discontinuation of steroid therapy, was the branchpoint of inflammatory markers between the two prognostic groups. CONCLUSION: The POD 57 CRP level predicts the surgical outcome of Kasai portoenterostomy. The postoperative anti-inflammatory management of BA can be monitored by the ubiquitous inflammatory biomarkers CRP and the preoperative lymphocyte ratio.

How should we treat representative neonatal surgical diseases with congenital heart disease?

PURPOSE: Representative neonatal surgical diseases are often complicated by congenital heart disease (CHD). We reviewed our decade of experience from the perspective of the prognosis and report on the management of infants with CHD. METHODS: Cases with and without CHD between 2011 and 2020 were retrospectively compared. Qualitative data were analyzed using a chi-square test with Yates' correction, and quantitative data were compared using Student's t-test. RESULTS: Of the 275 neonatal surgical cases, 36 had CHD (13.1%). Ventricular septal defect was the most common cardiac anomaly, followed by atrial septal defect. Esophageal atresia showed the highest complication rate of CHD (43.8%, 14/32) followed by duodenal atresia (38.5%, 10/26). The mortality rates of patients with and without CHD (22.2% [8/36] vs. 1.3% [3/239]) were significantly different (χ2 = 30.6, p < 0.0001). Of the eight deaths with CHD, six patients had cyanotic complex CHD. Notably, four of these patients died from progression of inappropriate hemodynamics in the remote period after definitive non-cardiac surgery. CONCLUSION: Considering its high-mortality, the presence of CHD, especially cyanotic heart disease, is an important issue to consider in the treatment of neonatal surgical diseases. Pediatric surgeons should be alert for changes in hemodynamics after surgery, as these may affect mortality.

Differential gastric emptiness according to preoperative stomach position in neurological impaired patients who underwent laparoscopic fundoplication and gastrostomy.

PURPOSE: We sometimes experienced prolonged delayed gastric emptying (DGE) in neurologically impaired patients undergoing laparoscopic fundoplication and gastrostomy. We explored the difference in the DGE rate according to the preoperative stomach position. METHODS: Thirty-two neurological impaired patients who underwent laparoscopic fundoplication and gastrostomy between 2015 and 2019 were classified into two groups based on stomach position: non-elevated stomach position (NESP) and elevated stomach position (ESP). Patients' characteristics, operative result and postoperative gastric emptying were reviewed. RESULTS: The 11 ESP patients were significantly older than the 21 NESP patients (p < 0.05). The ESP patients had a significantly heavier body weight (BW) than the NESP patients (p < 0.05). The time taken (days) to reduce gastric drainage (days, below BW × 10 ml) in the NESP (4.3 ± 3.6) was significantly longer than that of ESP (1.3 ± 1.6) (p < 0.05). The time taken (days) to achieve full enteral nutrition in the NESP (14.1 ± 8.9) was significantly longer than that of the ESP patients (8.8 ± 3.1) (p < 0.05). CONCLUSION: Elevated stomach position (ESP) patients archived full enteral nutrition earlier than NESP patients after laparoscopic fundoplication and gastrostomy. Stomach position correction might, therefore, be involved in the incidence of DGE.

What is the optimal lipid emulsion for preventing intestinal failure-associated liver disease following parenteral feeding in a rat model of short-bowel syndrome?

PURPOSE: Composite lipid emulsion (CLE) has been used for intestinal failure-associated liver disease (IFALD) to compensate for the disadvantages of soybean oil lipid emulsion (SOLE) or fish oil lipid emulsion (FOLE). However, the influence of its administration is unclear. We evaluated the effects of these emulsions on IFALD using a rat model of the short-bowel syndrome. METHODS: We performed jugular vein catheterization and 90% small bowel resection in Sprague-Dawley rats and divided them into four groups: control (C group), regular chow with intravenous administration of saline; and total parenteral nutrition co-infused with SOLE (SOLE group), CLE (CLE group) or FOLE (FOLE group). RESULTS: Histologically, obvious hepatic steatosis was observed in the SOLE and CLE groups but not the FOLE group. The liver injury grade of the steatosis and ballooning in the FOLE group was significantly better than in the SOLE group (p < 0.05). The TNF-α levels in the liver in the FOLE group were significantly lower than in the SOLE group (p < 0.05). Essential fatty acid deficiency (EFAD) was not observed in any group. CONCLUSION: Fish oil lipid emulsion attenuated hepatic steatosis without EFAD, while CLE induced moderate hepatic steatosis. The administration of CLE requires careful observation to prevent PN-induced hepatic steatosis.

Early definitive operation for patients with anorectal malformation was associated with a better long-term postoperative bowel function.

PURPOSE: In general, patients with anorectal malformation (ARM) undergo surgical treatment at around 6 months of age in Japan. We aimed to clarify whether the timing of a definitive operation affects the long-term bowel function. METHODS: Patient data were collected from 1984 to 2007. Fifty-two male patients with high- and intermediate-type ARM were enrolled. Patients were classified into two groups based on their operative period: the early group (EG) underwent anorectoplasty at < 5 months of age (n = 22); the late group (LG) underwent anorectoplasty at ≥ 5 months (n = 30). The bowel function was evaluated at 3, 5, 7, 9, and 11 years of age using the evacuation score (ES) of the Japan Society of Anorectal Malformation Study Group. RESULTS: The total score and four functional outcomes improved chronologically with age. The constipation score in the EG showed significantly better improvement in comparison to the LG. The total score and the incontinence score in the EG were significantly higher than those in the LG at 11 years of age. CONCLUSION: The long-term bowel function in the EG was better than that in the LG. Anorectoplasty at an early age was important for achieving a better postoperative bowel function in ARM patients.

The administration of hepatocyte growth factor prevents total parenteral nutrition-induced hepatocellular injury in a rat model.

PURPOSE: Total parenteral nutrition (TPN) sometimes induces parenteral nutrition-associated liver disease (PNALD). Hepatocyte growth factor (HGF) acts as a potent hepatocyte mitogen anti-inflammatory and antioxidant actions. We aimed to evaluate the effect of HGF on PNALD in a rat model of TPN. METHODS: A catheter was placed in the right jugular vein for 7-day continuous TPN. All rats were divided into three groups: TPN alone (TPN group), TPN plus intravenous HGF at 0.3 mg/kg/day [TPN + HGF (low) group], and TPN plus HGF at 1.0 mg/kg/day [TPN + HGF (high) group]. On day 7, livers were harvested and the histology, inflammatory cytokines and apoptosis were evaluated. RESULTS: Histologically, lipid droplets were apparent in the TPN group, but decreased in the TPN + HGF (low) and TPN + HGF (high) groups. The histological nonalcoholic fatty liver disease activity scores in the TPN + HGF (low) and TPN + HGF (high) groups were significantly lower than that in the TPN group (p < 0.01). There were no significant differences in the inflammatory cytokine levels of the three groups. The caspase-9 expression levels in the TPN + HGF (low) and TPN + HGF (high) groups were significantly decreased in comparison to that in the control group (p < 0.05). CONCLUSION: The intravenous administration of HGF attenuated hepatic steatosis induced by 7-day TPN dose dependently.

The protective effects of hepatocyte growth factor on the intestinal mucosal atrophy induced by total parenteral nutrition in a rat model.

PURPOSE: Total parental nutrition (TPN) causes gastrointestinal mucosal atrophy. The present study investigated the effects of hepatocyte growth factor (HGF) on the intestinal mucosal atrophy induced by TPN. METHODS: Rats underwent jugular vein catheterization and were divided into four groups: oral feeding (OF), TPN alone (TPN), TPN plus low-dose HGF (0.3 mg/kg/day; TPNLH), and TPN plus high-dose HGF (1.0 mg/kg/day; TPNHH). On day 7, rats were euthanized, and the small intestine was harvested and evaluated histologically. The expression of c-MET, a receptor of HGF, and nutrition transporter protein were evaluated using quantitative polymerase chain reaction. RESULTS: The jejunal villus height (VH) and absorptive mucosal surface area in the TPNHH group were significantly higher than in the TPN group (p < 0.05). The VH in the ileum showed the same trend only in the TPNHH group, albeit without statistical significance. The crypt cell proliferation rate (CCPR) of the jejunum in both HGF-treated groups was significantly higher than in the TPN group (p < 0.01). The expression of c-MET and transporter protein in all TPN-treated groups was decreased compared with that in the OF group. CONCLUSION: HGF attenuated TPN-associated intestinal mucosal atrophy by increasing the villus height, which was associated with an increase in CCPR.

Differential advantage of liver retraction methods in laparoscopic fundoplication for neurologically impaired patients: a comparison of three kinds of procedures.

AIM OF THE STUDY: Liver retraction during laparoscopic fundoplication is important for obtaining an optimal space. Several methods have been developed, but the risks and benefits are unclear. We compared three different approaches and evaluated their safety and utility. METHODS: Forty-three neurologically impaired patients who underwent laparoscopic fundoplication between 2005 and 2018 were classified into three groups: A, snake retractor method, n = 18; B, crural suture method, n = 13; C, needle grasper method, n = 12. Patients' characteristics and outcomes were reviewed. MAIN RESULTS: The liver retraction time was significantly shorter in group C than in A or B (p < 0.05). The operative times were shorter in groups B and C than in A. There were no significant differences in the liver enzyme levels. The liver enzyme levels increased temporarily but improved within a week. The C-reactive protein levels were significantly lower in group B than in A or C (p < 0.05). CONCLUSIONS: The most convenient method was the needle grasper method, as the other two approaches create conflict with the operator's forceps. The crural suture method damages the liver less, but requires higher surgical skill levels. It is important to select the appropriate method according to the operator's skill and the patient's size and deformity.

Long-term remission of bilateral Wilms tumors that developed from premature separation of chromatids/mosaic variegated aneuploidy syndrome due to bilateral nephrectomy and peritoneal dialysis.

We report a 38-month-old Japanese male with premature chromatid separation/mosaic variegated aneuploidy syndrome bearing biallelic BUB1B germline mutations who suffered from bilateral Wilms tumor. After right nephrectomy, dactinomycin monotherapy was administered for the left Wilms tumor; however, severe adverse reaction prevented the patient from receiving further chemotherapy. Left nephrectomy was then performed without postoperative chemotherapy. The patient survived for 15 months after bilateral nephrectomy without peritoneal relapse, metastasis of Wilms tumor, or the occurrence of rhabdomyosarcoma and maintained a good quality of life while receiving peritoneal dialysis at home.

Microvascular proliferation of the portal vein branches in the liver of biliary atresia patients at Kasai operation is associated with a better long-term clinical outcome.

AIM OF THE STUDY: We previously showed an increased number of smaller portal vein (PV) branches in the portal areas of liver biopsy specimens of biliary atresia (BA) patients. We evaluated the correlation between this histopathological feature and the prognosis. PATIENTS AND METHODS: Twenty-five consecutive patients with BA encountered between 2000 and 2012 were classified into three prognostic groups based on their postoperative outcomes: Excellent (n = 11) for native-liver survivors with a normal liver function, Good (n = 6) for native-liver survivors with liver dysfunction, and Poor (n = 8) for survivors after liver transplant or on a waiting list. Data from morphometrical analyses, including the fibrotic portal area, numbers of PVs, diameter and total area of PV branches, were statistically compared among the three groups. MAIN RESULTS: The number of PV branches per unit area of the whole-liver specimen in the poor prognostic group was significantly lower than that in the excellent group (3.1 ± 0.6 vs. 5.2 ± 2.0/mm2, p = 0.03). There were no significant differences in the other parameters. CONCLUSIONS: This is the first report on the relationships between morphometrically analyzed PV branches and the postoperative course in BA patients. The portal venous system is involved as the primary lesion in BA.