Outcomes and Durability of Hepatic Reduction after Combined Partial Hepatectomy and Cyst Fenestration for Massive Polycystic Liver Disease

Clinical manifestation, epidemiology, genetic basis, potential molecular targets, and current treatment of polycystic liver disease

Polycystic liver disease (PLD) is a rare condition observed in three genetic diseases, including autosomal dominant polycystic liver disease (ADPLD), autosomal dominant polycystic kidney disease (ADPKD), and autosomal recessive polycystic kidney disease (ARPKD). PLD usually does not impair liver function, and advanced PLD becomes symptomatic when the enlarged liver compresses adjacent organs or increases intra-abdominal pressure. Currently, the diagnosis of PLD is mainly based on imaging, and genetic testing is not required except for complex cases. Besides, genetic testing may help predict patients' prognosis, classify patients for genetic intervention, and conduct early treatment. Although the underlying genetic causes and mechanisms are not fully understood, previous studies refer to primary ciliopathy or impaired ciliogenesis as the main culprit. Primarily, PLD occurs due to defective ciliogenesis and ineffective endoplasmic reticulum quality control. Specifically, loss of function mutations of genes that are directly involved in ciliogenesis, such as Pkd1, Pkd2, Pkhd1, and Dzip1l, can lead to both hepatic and renal cystogenesis in ADPKD and ARPKD. In addition, loss of function mutations of genes that are involved in endoplasmic reticulum quality control and protein folding, trafficking, and maturation, such as PRKCSH, Sec63, ALG8, ALG9, GANAB, and SEC61B, can impair the production and function of polycystin1 (PC1) and polycystin 2 (PC2) or facilitate their degradation and indirectly promote isolated hepatic cystogenesis or concurrent hepatic and renal cystogenesis. Recently, it was shown that mutations of LRP5, which impairs canonical Wnt signaling, can lead to hepatic cystogenesis. PLD is currently treated by somatostatin analogs, percutaneous intervention, surgical fenestration, resection, and liver transplantation. In addition, based on the underlying molecular mechanisms and signaling pathways, several investigational treatments have been used in preclinical studies, some of which have shown promising results. This review discusses the clinical manifestation, complications, prevalence, genetic basis, and treatment of PLD and explains the investigational methods of treatment and future research direction, which can be beneficial for researchers and clinicians interested in PLD.

Extrarenal Manifestations: Polycystic Liver Disease and Its Complications

The liver is the commonest site of involvement outside of the kidney in autosomal dominant polycystic kidney disease. Most individuals with polycystic liver disease are asymptomatic and require no therapeutic interventions, but a small number of affected individuals who experience symptomatic polycystic liver disease develop medical complications as a result of massive enlargement of cyst number and size and hepatic parenchyma and its subsequent associated complications. This can lead to deterioration in overall health and quality of life, increasing morbidity and mortality. In this review, we will touch upon disease pathogenesis, prevalence, and complications and discuss recent advances in surgical and medical management.

Shifting perspectives in liver diseases after kidney transplantation

Liver diseases after kidney transplantation range from mild biochemical abnormalities to severe hepatitis or cirrhosis. The causes are diverse and mainly associated with hepatotropic viruses, drug toxicity and metabolic disorders. Over the past decade, the aetiology of liver disease in kidney recipients has changed significantly. These relates to the use of direct-acting antiviral agents against hepatitis C virus, the increasing availability of vaccination against hepatitis B and a better understanding of drug-induced hepatotoxicity. In addition, the emergence of the severe acute respiratory syndrome coronavirus 2 pandemic has brought new challenges to kidney recipients. This review aims to provide healthcare professionals with a comprehensive understanding of recent advances in the management of liver complications in kidney recipients and to enable them to make informed decisions regarding the risks and impact of liver disease in this population.

Benign liver lesions 2022: Guideline for clinical practice of Associazione Italiana Studio del Fegato (AISF), Società Italiana di Radiologia Medica e Interventistica (SIRM), Società Italiana di Chirurgia (SIC), Società Italiana di Ultrasonologia in Medicina e Biologia (SIUMB), Associazione Italiana di Chirurgia Epatobilio-Pancreatica (AICEP), Società Italiana Trapianti d'Organo (SITO), Società Italiana di Anatomia Patologica e Citologia Diagnostica (SIAPEC-IAP) - Part I - Cystic lesions

Benign liver lesions are increasingly diagnosed in daily clinical practice due to the growing use of imaging techniques for the study of the abdomen in patients who have non-specific symptoms and do not have an increased risk of hepatic malignancy. They include simple or parasitic cysts and solid benign tumors which differ widely in terms of prevalence, clinical relevance, symptoms and natural history and often lead to significant clinical problems relating to diagnosis and clinical management. Following the need to have updated guidelines on the management of benign focal liver lesions, the Scientific Societies mainly involved in their management have promoted the drafting of a new dedicated document. This document was drawn up according to the present Italian rules and methodologies necessary to produce clinical, diagnostic, and therapeutic guidelines based on evidence. Here we present the first part of the guideline, concerning the characterization of focal hepatic lesions detected by ultrasound, and the diagnosis and clinical management of simple and parasitic hepatic cysts, and of polycystic liver disease.

Treatment of Polycystic Liver Disease: Impact on Patient-reported Symptom Severity and Health-related Quality of Life

Polycystic liver disease (PLD) is a genetic disorder in which patients suffer from progressive development of multiple (>10) hepatic cysts. Most patients remain asymptomatic during the course of their disease. However, a minority of PLD patients suffer from symptoms caused by hepatomegaly leading to serious limitations in daily life. Untreated symptomatic PLD patients score significantly worse on health-related quality of life (HRQoL) compared to age and gender-matched populations. Currently, liver transplantation is the only curative treatment for PLD. The main goal of other available therapies is to strive for symptomatic relief and improvement of HRQoL by suppressing disease progression. In this review, we summarize the effect of PLD treatment on patient-reported outcome measures with a distinction between HRQoL and symptom severity. At present there is heterogeneity in application of questionnaires and no questionnaire is available that measures both HRQoL and PLD symptom severity. Therefore, we recommend the combination of a validated PLD-specific symptom severity questionnaire and a general HRQoL questionnaire to evaluate treatment success as a minimal core set. However, the specific choice of questionnaires depends on treatment choice and/or research question. These questionnaires may serve as a biomarker of treatment response, failure, and adverse events.

EASL Clinical Practice Guidelines on the management of cystic liver diseases

The advent of enhanced radiological imaging techniques has facilitated the diagnosis of cystic liver lesions. Concomitantly, the evidence base supporting the management of these diseases has matured over the last decades. As a result, comprehensive clinical guidance on the subject matter is warranted. These Clinical Practice Guidelines cover the diagnosis and management of hepatic cysts, mucinous cystic neoplasms of the liver, biliary hamartomas, polycystic liver disease, Caroli disease, Caroli syndrome, biliary hamartomas and peribiliary cysts. On the basis of in-depth review of the relevant literature we provide recommendations to navigate clinical dilemmas followed by supporting text. The recommendations are graded according to the Oxford Centre for Evidence-Based Medicine system and categorised as 'weak' or 'strong'. We aim to provide the best available evidence to aid the clinical decision-making process in the management of patients with cystic liver disease.

Polycystic Liver Disease: Pathophysiology, Diagnosis and Treatment

Polycystic liver disease (PLD) is a clinical condition characterized by the presence of more than 10 cysts in the liver. It is a rare disease Of genetic etiology that presents as an isolated disease or assoc\iated with polycystic kidney disease. Ductal plate malformation, ciliary dysfunction, and changes in cell signaling are the main factors involved in its pathogenesis. Most patients with PLD are asymptomatic, but in 2–5% of cases the disease has disabling symptoms and a significant reduction in quality of life. The diagnosis is based on family history of hepatic and/or renal polycystic disease, clinical manifestations, patient age, and polycystic liver phenotype shown on imaging examinations. PLD treatment has evolved considerably in the last decades. Somatostatin analogues hold promise in controlling disease progression, but liver transplantation remains a unique curative treatment modality.

Volume Progression and Imaging Classification of Polycystic Liver in Early Autosomal Dominant Polycystic Kidney Disease

BACKGROUND AND OBJECTIVES

The progression of polycystic liver disease is not well understood. The purpose of the study is to evaluate the associations of polycystic liver progression with other disease progression variables and classify liver progression on the basis of patient's age, height-adjusted liver cystic volume, and height-adjusted liver volume.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Prospective longitudinal magnetic resonance images from 670 patients with early autosomal dominant polycystic kidney disease for up to 14 years of follow-up were evaluated to measure height-adjusted liver cystic volume and height-adjusted liver volume. Among them, 245 patients with liver cyst volume >50 ml at baseline were included in the longitudinal analysis. Linear mixed models on log-transformed height-adjusted liver cystic volume and height-adjusted liver volume were fitted to approximate mean annual rate of change for each outcome. The association of sex, body mass index, genotype, baseline height-adjusted total kidney volume, and Mayo imaging class was assessed. We calculated height-adjusted liver cystic volume ranges for each specific age and divided them into five classes on the basis of annual percentage increase in height-adjusted liver cystic volume.

RESULTS

The mean annual growth rate of height-adjusted liver cystic volume was 12% (95% confidence interval, 11.1% to 13.1%; P<0.001), whereas that for height-adjusted liver volume was 2% (95% confidence interval, 1.9% to 2.6%; P<0.001). Women had higher baseline height-adjusted liver cystic volume than men, but men had higher height-adjusted liver cystic volume growth rate than women by 2% (95% confidence interval, 0.4% to 4.5%; P=0.02). Whereas the height-adjusted liver cystic volume growth rate decreased in women after menopause, no decrease was observed in men at any age. Body mass index, genotype, and baseline height-adjusted total kidney volume were not associated with the growth rate of height-adjusted liver cystic volume or height-adjusted liver volume. According to the height-adjusted liver cystic volume growth rate, patients were classified into five classes (number of women, men in each class): A (24, six); B (44, 13); C (43, 48); D (28, 17); and E (13, nine).

CONCLUSIONS

Compared with height-adjusted liver volume, the use of height-adjusted liver cystic volume showed greater separations in volumetric progression of polycystic liver disease. Similar to the Mayo imaging classification for the kidney, the progression of polycystic liver disease may be categorized on the basis of patient's age and height-adjusted liver cystic volume.

Polycystic liver: automatic segmentation using deep learning on CT is faster and as accurate compared to manual segmentation

OBJECTIVE

This study aimed to develop and investigate the performance of a deep learning model based on a convolutional neural network (CNN) for the automatic segmentation of polycystic livers at CT imaging.

METHOD

This retrospective study used CT images of polycystic livers. To develop the CNN, supervised training and validation phases were performed using 190 CT series. To assess performance, the test phase was performed using 41 CT series. Manual segmentation by an expert radiologist (Rad1a) served as reference for all comparisons. Intra-observer variability was determined by the same reader after 12 weeks (Rad1b), and inter-observer variability by a second reader (Rad2). The Dice similarity coefficient (DSC) evaluated overlap between segmentations. CNN performance was assessed using the concordance correlation coefficient (CCC) and the two-by-two difference between the CCCs; their confidence interval was estimated with bootstrap and Bland-Altman analyses. Liver segmentation time was automatically recorded for each method.

RESULTS

A total of 231 series from 129 CT examinations on 88 consecutive patients were collected. For the CNN, the DSC was 0.95 ± 0.03 and volume analyses yielded a CCC of 0.995 compared with reference. No statistical difference was observed in the CCC between CNN automatic segmentation and manual segmentations performed to evaluate inter-observer and intra-observer variability. While manual segmentation required 22.4 ± 10.4 min, central and graphics processing units took an average of 5.0 ± 2.1 s and 2.0 ± 1.4 s, respectively.

CONCLUSION

Compared with manual segmentation, automated segmentation of polycystic livers using a deep learning method achieved much faster segmentation with similar performance.

KEY POINTS

• Automatic volumetry of polycystic livers using artificial intelligence method allows much faster segmentation than expert manual segmentation with similar performance. • No statistical difference was observed between automatic segmentation, inter-observer variability, or intra-observer variability.

[What is evidence-based in the treatment of autosomal dominant polycystic kidney disease?]

The cystic transformation of the kidneys and liver are the most common symptoms of autosomal dominant polycystic kidney disease (prevalence 1:400-1:1000). A set of other manifestations can be observed less frequently, such as intracranial aneurysms. End-stage renal disease affects 50% of patients by the age of 70 years. To date, a targeted treatment is only available for patients at risk of rapidly progressive kidney failure. In 2015, the vasopressin receptor antagonist tolvaptan was approved in Germany for slowing down the decline of renal function in autosomal dominant polycystic kidney disease. Selecting the patients that benefit from tolvaptan treatment remains a major challenge. In recent years numerous clinical trials were carried out showing unspecific approaches to slow down the decline in renal function: strictly controlling blood pressure is one of the most important factors. Furthermore, unspecific approaches comprise suppression of vasopressin by sufficient fluid intake and restricted intake of salt. Weight reduction is recommended for obese patients. Lacking more causal approaches, these unspecific measures should be exploited in all patients. Currently, preclinical and clinical trials are testing numerous agents for the establishment of targeted treatment against the cystic degeneration of the kidneys and liver. This also includes dietary approaches. So far, in contrast to other genetic diseases, there are currently no gene therapy approaches for autosomal dominant polycystic kidney disease.

Preserving the organ donor pool and suprahepatic vena cava: Case series of transverse hepatectomy for polycystic liver disease

Management of symptomatic polycystic liver disease (PLD) has remained primarily unchanged since the early 20th century when multiple case reports described management of non-parasitic liver cysts. In 1968, Lin et al. described the fenestration procedure, "aspiration of the cysts, incision, partial excision with or without external drainage, or marsupilization and anastomosis to the gastrointestinal tract". Further surgical options have included cyst sclerotherapy, laparoscopic cyst aspiration, partial hepatectomy, and orthotopic liver transplant (OLT). Recently there has been discussion of medical management with somatostatin analogs to reduce hepatomegaly in PLD with varying success. There is no current consensus on treatment or standard of care for symptomatic PLD, it is largely up to surgeon preference and ability; however, there has been a movement toward early OLT with Model for End-Stage Liver Disease (MELD) score exception points. This case series reviews two female patients with normal renal and hepatic function with symptomatic PLD treated with transverse hepatectomy. We propose that patients suffering from symptomatic PLD, with retained renal and hepatic function, can be treated with transverse hepatectomy conserving limited donor livers for decompensated patients; moreover, transverse hepatectomy does not disrupt the major suprahepatic vena cava preserving potential surgical access for future OLT.

Polycystic liver disease with lethal abdominal wall rupture: a case report

Background

Polycystic liver disease is a clinical feature of autosomal dominant polycystic kidney disease, and it can sometimes cause health damage more serious than polycystic kidney. Dialysis therapy can be used for renal failure, but liver transplantation is the only method available for liver failure. Thus, giant and multiple hepatic cysts may affect mortality. However, liver transplantation is not indicated in many cases because of the preserved liver function.

Case presentation

A 54-year-old Japanese woman with polycystic liver disease was transferred back to our hospital for abdominal pain caused by liver cyst infection with abdominal wall herniation. She had been diagnosed with polycystic liver disease associated with sporadic autosomal dominant polycystic kidney disease 25 years earlier. Although she had several surgical interventions to reduce her liver volume, including right hepatic lobectomy and fenestration for liver cysts in another hospital, she needed further repair of the recurrent incisional herniation with patch graft surgery using fascia lata to cover the herniation site. However, new herniation sites reemerged in the fragile abdominal wall area around the patch, and therefore, she reduced the recurrent abdominal wall herniation by herself. Recurrent intestinal obstructions were luckily released by fasting with decompression treatment via nasogastric tube insertion, but multiple skin ulcers around the enlarged hernia sac gradually developed, and ascites was extremely difficult to control with any medication. At final admission, her abdominal wall was even more prominent, causing shortness of breath, and it spontaneously ruptured many times, which was accompanied by discharge of around 5 liters of ascites each time. She died from sepsis caused by drug-resistant Enterococcus.

Conclusions

We report a case of autosomal dominant polycystic kidney disease with ruptured abdominal wall resulting from a hepatic cyst enlargement despite multiple laparotomy operations. Throughout the entire disease course, her liver volume increased rapidly, and her quality of life was severely impaired, but she could not undergo liver transplantation after readmission to our hospital. We will discuss the therapeutic strategy for this patient, including the timing and indication for liver transplantation.

Partial major hepatectomy with cyst fenestration for polycystic liver disease: Indications, short and long-term outcomes

BACKGROUND AND OBJECTIVE

Symptomatic polycystic liver disease (PLD) with massive hepatomegaly represents a challenging surgical issue. In this work, we focused on early and long term outcomes after partial hepatectomy with cyst fenestration (PHCF) in selected patients.

METHODS

All patients who had PHCF for treatment of PLD between January 2003 and December 2019 in our center were included in this study. PHCF was undertaken if at least one hepatic section was relatively spared from PLD, afferent and efferent hepatic vasculature was patent, and liver function was maintained.

RESULTS

Twenty nine patients (25 women) with a mean age of 54.6 ± 9 years underwent PHCF. Major hepatectomy was performed in all cases with 4.3 ± 0.8 resected segments. Overall perioperative morbidity (Clavien ≥ II) and mortality rates were 41.4.6% and 13.8% respectively. Significant postoperative liver volume reduction was 52.8% within the first year and 55.5% thereafter. From preoperative evaluation, performance status (PS) normalized or improved in 84% of patients. After a mean follow-up time of 70.8 ± 65 months, overall patient survival was 82.7%. In univariate analysis, PS, initial liver volume, operative time and transfusion were associated with post-operative complications and PS, preoperative cyst infection, portal hypertension, transfusion, postoperative sepsis and persistent ascites were associated with mortality.

CONCLUSIONS

Our study confirms that in spite of significant morbidity rate, PHCF allows a massive reduction of liver volume in selected patients with symptomatic PLD and is highly and durably effective for the reduction of liver volume and improvement of quality of life.

Laparoscopic hepatic lobectomy for symptomatic polycystic liver disease

BACKGROUND

Laparoscopic fenestration has largely replaced open fenestration of liver cysts. However, most hepatectomies for polycystic liver disease (PCLD) are performed open. Outcomes data on laparoscopic hepatectomy for PCLD are lacking.

METHODS

Patients who underwent surgery for PCLD at a single institution between 2010 and 2019 were reviewed and grouped by operative approach. Pre- and post-operative volumes were calculated for patients who underwent resection. Primary outcomes were: volume reduction, re-admission and postoperative complications.

RESULTS

Twenty-six patients were treated for PCLD: 13 laparoscopic fenestration, nine laparoscopic hepatectomy, three open hepatectomy and one liver transplantation. Median length of stay for patients after laparoscopic resection was 3 days (IQR 2-3). The only complication was post-operative atrial fibrillation in one patient. There were no readmissions. Overall volume reduction was 51% (range 22-69) for all resections, 32% (range 22-46) after open resection and 56% (range 39-69) after laparoscopic resection.

CONCLUSION

Volume reduction achieved through laparoscopic approach exceeded open volume reduction at this institution and is comparable to volume reduction in previously published open resection series. Adequate volume reduction can be accomplished by laparoscopic means with acceptable postoperative morbidity.

Symptom relief and quality of life after combined partial hepatectomy and cyst fenestration in highly symptomatic polycystic liver disease

BACKGROUND

Polycystic liver disease can cause severe symptomatic hepatomegaly. Combined partial hepatectomy and cyst fenestration can be performed to reduce liver volume and symptom burden. We aimed to assess change in symptom relief and quality of life 6 months after partial hepatectomy and cyst fenestration in polycystic liver disease patients.

METHOD

We established a prospective cohort between 2014 and 2018 at a referral center in the United States. Patients who underwent partial hepatectomy and cyst fenestration for volume-related symptoms were included. Primary outcome was change in polycystic liver disease-related symptoms, measured with Polycystic Liver Disease Questionnaire. Secondary outcomes were change in liver volume (computed tomography/ magnetic resonance imaging) and change in quality of life, measured with the 12-Item Short Form Survey and the EuroQoL Visual Analogue Scale. Questionnaire scores range from 0 to 100 and were assessed before and 6 months after partial hepatectomy and cyst fenestration. Surgical complications were scored according to Clavien-Dindo (grade 1 to 5).

RESULTS

We included 18 patients (mean age 52 years, 82% female). Partial hepatectomy and cyst fenestration reduced median liver volume (4,917 to 2,120 mL). Symptoms, measured with Polycystic Liver Disease Questionnaire, decreased (76.9 to 34.8 points; P < .001) 6 months after surgery; 15/16 symptoms declined after treatment, with the most impact seen on early satiety and dyspnea. Quality of life also improved after surgery: median physical and mental component scales of the 12-Item Short Form Survey and EuroQoL Visual Analog Scale increased (24.9 to 45.7, P = .004; 40.5 to 55.4, P = .02; and 40.0 to 72.5, P = .003). Major complications (grade 4) occurred in 2 patients. There was no procedure-related mortality.

CONCLUSION

Partial hepatectomy and cyst fenestration substantially improves symptom burden and quality of life in highly symptomatic polycystic liver disease patients.

Polycystic liver disease: Classification, diagnosis, treatment process, and clinical management

Polycystic liver disease (PLD) is a rare hereditary disease that independently exists in isolated PLD, or as an accompanying symptom of autosomal dominant polycystic kidney disease and autosomal recessive polycystic kidney disease with complicated mechanisms. PLD currently lacks a unified diagnostic standard. The diagnosis of PLD is usually made when the number of hepatic cysts is more than 20. Gigot classification and Schnelldorfer classification are now commonly used to define severity in PLD. Most PLD patients have no clinical symptoms, and minority with severe complications need treatments. Somatostatin analogues, mammalian target of rapamycin inhibitor, ursodeoxycholic acid and vasopressin-2 receptor antagonist are the potentially effective medical therapies, while cyst aspiration and sclerosis, transcatheter arterial embolization, fenestration, hepatic resection and liver transplantation are the options of invasion therapies. However, the effectiveness of these therapies except liver transplantation are still uncertain. Furthermore, there is no unified strategy to treat PLD between medical centers at present. In order to better understand recent study progresses on PLD for clinical practice and obtain potential directions for future researches, this review mainly focuses on the recent progress in PLD classification, clinical manifestation, diagnosis and treatment. For information, we also provided medical treatment processes of PLD in our medical center.

Severe polycystic liver diseases: hepatectomy or waiting for liver transplantation?: Two case reports

INTRODUCTION

Choice of treatment in patients with symptomatic polycystic liver diseases (PLD) remains controversial. Various surgical procedures aiming at eliminating symptomatic cysts are widely used in mild and advanced PLD patients, but liver transplantation is currently recommended as the only curative treatment especially in severe cases.

PATIENT CONCERNS

Case 1: A 51-year-old male was admitted for severe eating disorder and dyspnea for 2 months. He had been diagnosed as PLD, PKD, and hypertension for 9 years, with only antihypertensive drug therapy. No significant family history could be traced.Case 2: A 54-year-old female was admitted to our hospital for ventosity during nearly 5 years. She had been diagnosed as PLD and hypertension for 22 years, for which only aspiration-sclerotherapy therapy was performed for multiple times. Both her mother and sister were diagnosed with PLD previously.

DIAGNOSIS

They were diagnosed as PLD by medical history, family history, and computed tomography scan (multiple cysts dispersively presenting in the liver).

INTERVENTIONS

The 2 patients underwent hepatectomy with fenestration, and were well recovered with no mortality.

OUTCOMES

While case 1 only experienced relief of symptoms, case 2 experienced massive growth of hepatic parenchyma, which indicated positive prognosis and showed the possibility to avoid or at least postpone liver transplantation for a long time, considering the lack of liver parenchyma is one of the main reason for urgency of liver transplantation.

CONCLUSION

Here we described subradical polycystic hepatectomy, a special form of hepatectomy with fenestration modified by us, as a safe and effective treatment to potentially achieve long-term effects in PLD patients.

Management of portal hypertension and ascites in polycystic liver disease

Patients suffering from polycystic liver disease may develop Hepatic Venous Outflow Obstruction, Portal Vein Obstruction and/or Inferior Caval Vein Syndrome because of cystic mass effect. This can cause portal hypertension, leading to ascites, variceal haemorrhage or splenomegaly. For this review, we evaluate the evidence to provide clinical guidance for physicians faced with this complication. Diagnosis is made with imaging such as ultrasound, computed tomography or magnetic resonance imaging. Therapy includes conventional therapy with diuretics and paracentesis, and medical therapy using somatostatin analogues. Based on disease phenotype various (non-)surgical liver-volume reducing therapies, hepatic or portal venous stenting, transjugular intrahepatic portosystemic shunts and liver transplantation may be considered. Because of complicated anatomy, use of high-risk interventions and lack of empirical evidence, patients should be treated in expert centres.

Polyhedral Fenestration Technique Used for Combined Partial Hepatectomy and Cyst Fenestration for Polycystic Liver Disease: A Small Case Series

Objective:

To assess the safety and efficacy of “polyhedral fenestration technique” (PFT), which we newly developed, in combined hepatectomy and cyst fenestration (CHCF) for symptomatic polycystic liver disease (PLD).

Summary of background data:

CHCF for PLD has been reportedly less efficacious for its invasiveness because 50% to 70% patients suffered recurrent symptoms after CHCF.

Methods:

Patient characteristics, intra- and early postoperative variables were compared between 5 PLD patients undergoing CHCF performed with PFT (PLD group) and 95 patients with diseases other than PLD receiving hepatectomy without biliary reconstruction during the same period (Control group) to assess safety of PFT. Chronological changes in total liver volume (TLV) measured by computed tomography (CT) volumetry as well as recurrent symptoms after CHCF were investigated to assess long-term outcomes.

Results:

Although ≧ Clavien-Dindo grade 2 complications were more common in the PLD group than in the Control group (PLD vs Control, 5/5[100%] vs 27/95[28%], p=0.004), patient characteristics, intra-, and early postoperative variables, including ≧ Clavien-Dindo grade 3 complications, were comparable among the 2 groups. Postoperative observational period of the 5 PLD patients ranged 30 to 88 months with a median of 63. CT volumetry revealed that TLV continued to reduce up to 1 year after surgery and thereafter retained less than 0.5 times of preoperative TLV in all patients. Recurrent liver enlargement or recurrent symptoms were not observed in any of the 5 PLD patients.

Conclusions:

Although our case series was very small, newly-developed PFT in CHCF for PLD yielded acceptable safety and excellent long-term outcomes.

Polycystic kidney disease

Cystic kidneys are common causes of end-stage renal disease, both in children and in adults. Autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ARPKD) are cilia-related disorders and the two main forms of monogenic cystic kidney diseases. ADPKD is a common disease that mostly presents in adults, whereas ARPKD is a rarer and often more severe form of polycystic kidney disease (PKD) that usually presents perinatally or in early childhood. Cell biological and clinical research approaches have expanded our knowledge of the pathogenesis of ADPKD and ARPKD and revealed some mechanistic overlap between them. A reduced 'dosage' of PKD proteins is thought to disturb cell homeostasis and converging signalling pathways, such as Ca²⁺, cAMP, mechanistic target of rapamycin, WNT, vascular endothelial growth factor and Hippo signalling, and could explain the more severe clinical course in some patients with PKD. Genetic diagnosis might benefit families and improve the clinical management of patients, which might be enhanced even further with emerging therapeutic options. However, many important questions about the pathogenesis of PKD remain. In this Primer, we provide an overview of the current knowledge of PKD and its treatment.

Polycystic liver disease: Hepatic venous outflow obstruction lesions of the noncystic parenchyma have major consequences

In patients with polycystic liver disease (PLD), development of cysts induces hepatic venous outflow obstruction (HVOO) and parenchymal modifications, challenging the paradigm of a normal noncystic liver parenchyma. The aims were to reappraise the pathology of the noncystic parenchyma, by focusing on HVOO lesions; and to investigate the association with outflow obstruction at imaging and perioperative course after liver resection. This is a retrospective study conducted in one tertiary center between 1993 and 2014. PLD patients (n = 125) who underwent resection (n = 90) or transplantation (n = 35) were included. HVOO parenchymal lesions were assessed for all patients and a liver congestion score was built. Imaging was analysed for 45 patients with computed tomography scan, and perioperative course was assessed in resected patients. At pathology, 92% of patients had HVOO lesions, with sinusoidal dilatation being the most common feature. HVOO was more severe in patients who underwent transplantation compared to liver resection, as assessed by the congestion score. At imaging, all patients had HVOO with at least two hepatic veins involved. Mosaic enhancement pattern of the parenchyma was associated with the severity of hepatic vein obstruction (P = 0.045) and the compression of the inferior vena cava (P = 0.014). In case of liver resection, intraoperative course was characterized by hemorrhage, related to HVOO at imaging. Ascites (44%) and liver failure (9%) in the postoperative period were associated with blood losses and transfusions.

CONCLUSION

Hepatic venous outflow obstruction, including development of venous collaterality and parenchymal changes, is frequent in PLD and has major consequences on intraoperative bleeding and postoperative ascites and liver failure. Hepatic venous outflow obstruction should be taken into account to choose the most appropriate surgical treatment. (Hepatology 2017).

Clinical management of polycystic liver disease

A 41-year old female underwent a computed tomography (CT) scan in 2010 because of symptoms suggestive of appendicitis. Incidentally, multiple liver lesions characterised as cysts were detected. The presence of small to medium sized liver cysts (diameter between <1 cm and 4 cm) in all liver segments (>100 cysts) and absence of kidney cysts in the context of normal renal function led to the clinical diagnosis of autosomal dominant polycystic liver disease (ADPLD). Five years later she was referred to the outpatient clinic with increased abdominal girth, pain in the right upper abdomen and right flank, and early satiety. She had difficulties bending over and could neither cut her toenails nor tie her shoe laces. In her early twenties she had used oral contraception for five years. She has been pregnant twice. Clinical examination showed an enlarged liver reaching into the right pelvic region and crossing the midline of the abdomen. Laboratory testing demonstrated increased gamma-glutamyl transferase (80 IU/L, normal <40 IU/L) and alkaline phosphatase (148 IU/L, normal <100 IU/L) levels. Bilirubin, albumin and coagulation times were within the normal range. A new CT scan in 2015 was compatible with an increased number and size of liver cysts. The diameter of cysts varied between <1 cm and 6 cm (anatomic distribution shown [Fig. 2B]). There were no signs of hepatic venous outflow obstruction, portal hypertension or compression on the biliary tract. Height-adjusted total liver volume (htTLV) increased from 2,667 ml/m in 2012 to 4,047 ml/m in 2015 (height 172 cm). The case we present here is not uncommon, and prompts several relevant questions.

Isolated polycystic liver disease genes define effectors of polycystin-1 function

Dominantly inherited isolated polycystic liver disease (PCLD) consists of liver cysts that are radiologically and pathologically identical to those seen in autosomal dominant polycystic kidney disease, but without clinically relevant kidney cysts. The causative genes are known for fewer than 40% of PCLD index cases. Here, we have used whole exome sequencing in a discovery cohort of 102 unrelated patients who were excluded for mutations in the 2 most common PCLD genes, PRKCSH and SEC63, to identify heterozygous loss-of-function mutations in 3 additional genes, ALG8, GANAB, and SEC61B. Similarly to PRKCSH and SEC63, these genes encode proteins that are integral to the protein biogenesis pathway in the endoplasmic reticulum. We inactivated these candidate genes in cell line models to show that loss of function of each results in defective maturation and trafficking of polycystin-1, the central determinant of cyst pathogenesis. Despite acting in a common pathway, each PCLD gene product demonstrated distinct effects on polycystin-1 biogenesis. We also found enrichment on a genome-wide basis of heterozygous mutations in the autosomal recessive polycystic kidney disease gene PKHD1, indicating that adult PKHD1 carriers can present with clinical PCLD. These findings define genetic and biochemical modulators of polycystin-1 function and provide a more complete definition of the spectrum of dominant human polycystic diseases.

Utilization of Distilled Water Lavage for Localized Fluid Collection After Combined Hepatectomy and Cyst Fenestration for Polycystic Liver Disease

Ascites necessitating persistent drainage or paracentesis after drain removal has been found among early postoperative complications after combined hepatectomy and cyst fenestration (CHCF) for polycystic liver disease (PLD). It has been reportedly observed in 20% to 70% of cases and seemed to easily cause recurrent symptoms unless properly treated. We utilized distilled water lavage for treating localized fluid collection after combined hepatectomy and cyst fenestration for PLD. A 63-year-old female patient underwent CHCF for PLD, which caused severe abdominal fullness. Early postoperative course was uneventful until 10 days after surgery when the patient suffered sudden abdominal fullness and resultant severe anorexia because of right subphrenic massive localized monolocular fluid collection diagnosed by abdominal computed tomography—although total liver volume was reduced to less than half of that before surgery. Percutaneous drainage relieved symptoms immediately, but the drainage tube could not be removed because of massive outflow. Then we utilized distilled water lavage for treating this condition. After that, drain outflow dramatically reduced and the drainage tube was successfully removed. Total liver volume of the patient continued to reduce up to 1 year after surgery and retained less than one-third of preoperative total liver volume thereafter. Sustained reduction of total liver volume in the present case suggested a sclerosant effect of hypotonic cytocidal property of distilled water for cyst endothelium and/or retrieved effectiveness of fenestration. Hence, we consider this approach to be useful for patients with PLD receiving CHCF and thus present it here.