Pain management in polycystic kidney disease

Interventional pathway in the management of refractory chronic flank pain: Prospective series in 45 patients

BACKGROUND

Chronic flank pain can pose a therapeutic challenge. Current management centres on visceral pathology affecting the renal system. Acute exacerbations can be severe, requiring emergency admission. Patients usually have well-established visceral pathology including polycystic kidney disease, Fowler's syndrome, and renal calculi disease that often cause recurrent urinary tract infections. However, in many cases, despite negative investigations including imaging, biochemistry and urine analysis, flank pain persists. Abdominal myofascial pain syndrome is a poorly recognized pathology in this cohort. The report describes the underlying pathophysiology and a novel interventional management pathway for patients presenting with refractory flank pain secondary to abdominal myofascial pain syndrome.

METHODS

Adult patients with refractory chronic flank pain at a tertiary renal unit were included as a part of an on-going prospective longitudinal audit. Patients refractory to standard management were offered the interventional pathway. The pathway included two interventions: quadratus lumborum block with steroid and pulsed radio frequency treatment. Patients completed brief pain inventory and hospital anxiety and depression scale questionnaires at baseline, 3 and 6 months postprocedure. Outcomes collected included ability to maintain employment, change in opioid consumption at 6 months and impact on emergency hospital admissions at 12 months after initiation of the pathway.

RESULTS

Forty-five patients were referred to the pain medicine clinic over a seven-year period between 2014 and 2021. All patients were offered the interventions. Four patients refused due to needle phobia. Forty-one patients received transmuscular quadratus lumborum plane block with steroids. Twenty-seven patients (27/41, 66%) reported durable benefit at 6 months and six patients (6/41, 15%) had clinically significant relief at 3 months. Fifteen patients received pulsed radiofrequency to quadratus lumborum plane and 11 patients (73%) reported > 50% analgesia at 6 months. Treatment failure rate was 10% (4/41). Opioid consumption at 6 months and emergency admission at 12 months were reduced post intervention.

CONCLUSION

Abdominal myofascial pain syndrome is a poorly recognized cause of chronic flank pain syndrome. The interventional management pathway could be an effective solution in this cohort.

Options for approaches to nephrectomy in patients with end-stage chronic kidney disease caused by autosomal dominant polycystic kidney disease: A review

Autosomal-dominant polycystic kidney disease is a common kidney disease that affects all racial groups around the world, occupies one of the leading places in the structure of urological diseases and forms a significant contribution to the structure of all causes leading to the end stage of chronic renal failure, disabling patients in this group and hence leading to the inevitability of renal replacement therapy. A highly effective clinical method for replacing lost kidney function is kidney transplantation. Based on the fact that the number of patients with this pathology is increasing, it is necessary to search for and introduce clear criteria for the best care, taking into account the high likelihood of developing infectious complications, hematuria, the absence or presence of diuresis, arterial hypertension in this category of patients. The article reflects the various methods of nephrectomy in patients suffering from autosomal dominant polycystic kidney disease, as well as how approaches to nephrectomy have evolved. The results of complications, as well as patient and graft survival in domestic and foreign studies, in which bilateral or ipsilateral nephrectomy was used using open or laparoscopic access before, during or after kidney transplantation, are demonstrated. Preference is rightfully given to minimally invasive methods of surgical treatment. Taking into account the already reduced resources of the organism of these patients, the volume and method of surgical treatment should be carefully chosen, taking into account safety, efficacy and risk minimization.

Is autosomal dominant polycystic kidney disease an early sweet disease?

The clinical course of autosomal dominant polycystic kidney disease (ADPKD) starts in childhood. Evidence of the beneficial impact of early nephron-protective strategies and lifestyle modifications on ADPKD prognosis is accumulating. Recent studies have described the association of overweight and obesity with rapid disease progression in adults with ADPKD. Moreover, defective glucose metabolism and metabolic reprogramming have been reported in distinct ADPKD models highlighting these pathways as potential therapeutic targets in ADPKD. Several "metabolic" approaches are currently under evaluation in adults, including ketogenic diet, food restriction, and metformin therapy. No data are available on the impact of these approaches in childhood thus far. Yet, according to World Health Organization (WHO), we are currently facing a childhood obesity crisis with an increased prevalence of overweight/obesity in the pediatric population associated with a cardio-metabolic risk profile. The present review summarizes the knowledge about the role of glucose metabolism in the pathophysiology of ADPKD and underscores the possible harm of overweight and obesity in ADPKD especially in terms of long-term cardiovascular outcomes and renal prognosis.

Molecular Mechanisms of Epigenetic Regulation, Inflammation, and Cell Death in ADPKD

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder, which is caused by mutations in the PKD1 and PKD2 genes, characterizing by progressive growth of multiple cysts in the kidneys, eventually leading to end-stage kidney disease (ESKD) and requiring renal replacement therapy. In addition, studies indicate that disease progression is as a result of a combination of factors. Understanding the molecular mechanisms, therefore, should facilitate the development of precise therapeutic strategies for ADPKD treatment. The roles of epigenetic modulation, interstitial inflammation, and regulated cell death have recently become the focuses in ADPKD. Different epigenetic regulators, and the presence of inflammatory markers detectable even before cyst growth, have been linked to cyst progression. Moreover, the infiltration of inflammatory cells, such as macrophages and T cells, have been associated with cyst growth and deteriorating renal function in humans and PKD animal models. There is evidence supporting a direct role of the PKD gene mutations to the regulation of epigenetic mechanisms and inflammatory response in ADPKD. In addition, the role of regulated cell death, including apoptosis, autophagy and ferroptosis, have been investigated in ADPKD. However, there is no consensus whether cell death promotes or delays cyst growth in ADPKD. It is therefore necessary to develop an interactive picture between PKD gene mutations, the epigenome, inflammation, and cell death to understand why inherited PKD gene mutations in patients may result in the dysregulation of these processes that increase the progression of renal cyst formation.

Multidisciplinary management of chronic refractory pain in autosomal dominant polycystic kidney disease

BACKGROUND

Chronic pain is often difficult to manage in autosomal dominant polycystic kidney disease (ADPKD) patients and sometimes even leads to nephrectomy. We analyzed the long-term efficacy of our innovative multidisciplinary protocol to treat chronic refractory pain that aims to preserve kidney function by applying among other sequential nerve blocks.

METHODS

Patients were eligible if pain was present ≥3 months with a score of ≥50 on a visual analog scale (VAS) of 100, was negatively affecting quality of life and if there had been insufficient response to previous therapies, including opioid treatment. Treatment options were, in order, analgesics, cyst aspiration and fenestration, nerve blocks and nephrectomy.

RESULTS

A total of 101 patients were assessed in our clinic (mean age 50 ± 11 years, 65.3% females). Eight patients were treated with medication, 6 by cyst aspiration or fenestration, 63 by nerve blocks and 6 received surgery as the first treatment option. Overall, 76.9% experienced a positive effect on pain complaints shortly after treatment. The VAS score was reduced from 60/100 to 20/100 (P < 0.001) and patients decreased their number of nonopioid and opioid analgesics significantly (P < 0.001, P = 0.01, respectively). A substantial number of the patients (n = 51) needed additional treatment. At the end of follow-up in only 13 patients (12.9%) was surgical intervention necessary: 11 nephrectomies (of which 10 were in patients already on kidney function replacement treatment), 1 liver transplantation and 1 partial hepatectomy. After a median follow-up of 4.5 years (interquartile range 2.5-5.3), 69.0% of the patients still had fewer pain complaints.

CONCLUSIONS

These data indicate that our multidisciplinary treatment protocol appears effective in reducing pain in the majority of patients with chronic refractory pain, while postponing or even avoiding in most patients surgical interventions such as nephrectomy in most patients.

Developing a patient-centred tool for pain measurement and evaluation in autosomal dominant polycystic kidney disease

BACKGROUND

Pain affects 60% of the autosomal dominant polycystic kidney disease (ADPKD) population. Despite being an early and debilitating symptom, it is poorly characterized and management is suboptimal. This study aimed to develop an ADPKD-specific pain assessment tool (APAT) to facilitate pain research.

METHODS

Following a systematic review of PATs used in ADPKD studies and against international recommendations for pain trials, our multi-disciplinary team of clinical experts and patients constructed an ADPKD-pain conceptual framework of key pain evaluation themes. We compiled a new APAT covering domains prioritized within our framework using components of questionnaires validated in other chronic pain disorders. The APAT was administered longitudinally within a randomized high-water intake trial (NCT02933268) to ascertain feasibility and provide pilot data on ADPKD pain.

RESULTS

Thirty-nine ADPKD participants with chronic kidney disease Stages 1-4 provided 129 APAT responses. Each participant completed a median of 3 (range 1-10) assessments. Respondents' mean ± standard deviation age was 47 ± 13 years; 59% (23) were female; and 69% (27) had enlarged kidneys with median time from diagnosis 14.2 (interquartile range 7.0-25.9) years. Pain (52%) and associated analgesic use (29%) were common. Pain severity was associated with increasing age [odds ratio (OR) = 1.07, P = 0.009], female gender (OR = 4.34, P = 0.018), estimated glomerular filtration rate <60 mL/min/1.73 m2 (OR = 5.45, P = 0.021) and hypertension (OR = 12.11, P = 0.007), but not with kidney size (P = 0.23). The APAT achieved good internal consistency (Cronbach's alpha coefficient = 0.91) and test-retest reliability (domain intra-class correlation coefficients ranging from 0.62 to 0.90).

CONCLUSIONS

The APAT demonstrated good acceptability and reliability, and following further validation in a larger cohort could represent an invaluable tool for future ADPKD pain studies.

Staged versus concurrent native nephrectomy and renal transplantation in patients with autosomal dominant polycystic kidney disease: A systematic review

BACKGROUND

Patients with Autosomal Dominant Polycystic Kidney Disease (ADPKD) frequently undergo native nephrectomy before transplantation. The nephrectomy may be a staged procedure or undertaken simultaneously with transplantation. When performed simultaneously, the transplant procedure is more prolonged, involves a larger operative field and incision. There is also a concern of a greater risk of graft loss with simultaneous nephrectomy and transplantation. Moreover, staged surgery may allow nephrectomy to be performed before immunosuppression introduction via a smaller incision or involving a minimally invasive approach. However, staged nephrectomy may require a period of dialysis not otherwise necessary if a transplant and nephrectomy were simultaneous. Moreover, only a single procedure is needed, implying the avoidance of a prior nephrectomy and its attendant morbidity in a patient with chronic renal insufficiency. To account for these issues, this study aims to compare the cumulative morbidity of two-staged procedures versus a single simultaneous approach in term of morbidity and graft outcomes.

OBJECTIVES

This study aims to systematically review the literature to determine whether a staged or simultaneous approach to native nephrectomy in ADPKD is the optimal approach in terms of morbidity and graft outcomes.

METHODS

A literature search of MEDLINE and EMBASE was conducted to identify published systematic reviews, randomized control trials, case-controlled studies and case studies. Data comparing outcomes of staged and simultaneous nephrectomy for patients undergoing kidney transplantation was extracted and analyzed. The main outcomes analyzed were length of hospitalization, blood loss, operative time, other early postoperative complications and risk of graft thrombosis. Meta-analysis was conducted where appropriate.

RESULTS

Seven retrospective cohort studies were included in the review. There was a total of 385 patients included in the analysis, of whom 273 patients underwent simultaneous native nephrectomy and kidney transplantation. Meta-analysis showed an increased cumulative operative time in staged procedures (RR 1.86；95% CI 0.43-3.29 p = 0.01) and increased risk of blood transfusions (RR 2.69; 95% CI 1.92-3.46 p < 0.00001). For the transplant procedure, there were no significant difference in the length of stay (RR 1.03; 95% CI -2.01-4.14 p = 0.52), major postoperative complications (RR 0.02; 95% CI -0.15-0.10 p = 0.74) and vascular thromboses (RR 1.42 95% CI 0.23-8.59 p = 0.7).

CONCLUSION

The results suggest that staged nephrectomy followed by kidney transplantation is associated with a longer cumulative operative time and increased cumulative risk of blood transfusions. There is no evidence to suggest that performing a simultaneous nephrectomy and kidney transplant procedure increases the perioperative mortality rate, major postoperative complication rates or risk of vascular thrombosis.

Laparoscopic Nephrectomy for Massive Kidneys in Polycystic Kidney Disease

Background and Objectives:

Laparoscopic nephrectomy is now considered a feasible surgical approach, even for large kidneys. In the case of massive kidneys, laparoscopy can be problematic, so that some authors suggest an open approach. However, previous studies have shown that hand-assisted laparoscopic nephrectomy (HALN) may represent a useful compromise.

We describe our hand-assisted laparoscopic technique for nephrectomy of large kidneys (> 2500 g) to encourage the use of laparoscopy for nephrectomy in autosomal dominant polycystic kidney disease.

Methods:

We retrospectively analyzed data from 26 nephrectomies in 17 patients who underwent HALN for ADPKD and compared them to a group of 22 nephrectomies in 18 patients with open surgical technique.

Results:

The duration of the procedure was significantly longer in the laparoscopic group, with a median of 180 minutes versus 90 minutes for the unilateral nephrectomies, and 240 minutes versus 122 minutes for the bilateral procedures. The median kidney weight in the open group was 2500 g (range 1300 – 4500 g), while the median weight in the HALN group was 2375 g (range 1000 – 4700 g). The median hospital stay was comparable. No significant differences were recorded in the intra- and postoperative complication rate.

Conclusion:

Hand-assisted laparoscopic nephrectomy can be considered a technique of choice for patients suffering from ADPKD requiring nephrectomy, also with massive kidneys weighing more than 3500 g. Compared to open nephrectomy, HALN can be performed safely, with reasonably longer operating times and without major complications, and offers a significant reduction in hospitalization time, pain and postoperative discomfort.

Patient-reported outcome measures for pain in autosomal dominant polycystic kidney disease: A systematic review

Pain is a common symptom in people with autosomal dominant polycystic kidney disease (ADPKD), but it is assessed and reported inconsistently in research, and the validity of the measures remain uncertain. The aim of this study was to identify the characteristics, content, and psychometric properties of measures for pain used in ADPKD. We conducted a systematic review including all trials and observational studies that reported pain in people with ADPKD. Items from all measures were categorized into content and measurement dimensions of pain. We assessed the general characteristics and psychometric properties of all measures. 118 studies, we identified 26 measures: 12 (46%) measures were developed for a non-ADPKD population, 1 (4%) for chronic kidney disease, 2 (8%) for polycystic liver disease and 11 (42%) specifically for ADPKD. Ten anatomical sites were included, with the lower back the most common (10 measures [39%]), four measurement dimensions (intensity (23 [88%]), frequency (3 [12%]), temporality (2 [8%]), and sensory (21 [81%]), two pain types, nociceptive including visceral (15 [58%]) and somatic (5 [20%]), and neuropathic (2 [8%]), and twelve impact dimensions, where the most frequent was work (5 [31%]). The validation data for the measures were variable and only the ADPKD Impact Scale reported all psychometric domains. The measures for pain in ADPKD varied in terms of content and length, and most had not been validated in ADPKD. A standardized psychometrically robust measure that captures patient-important dimensions of pain is needed to evaluate and manage this debilitating complication of ADPKD.

The correlation between kidney volume and measured glomerular filtration rate in an Asian ADPKD population: a prospective cohort study

Background

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disorder that leads to end stage renal disease (ESRD). Cyst expansion in ADPKD is strongly associated with the decline in renal function. However, the correlation between total kidney volume (TKV) and glomerular filtration rate (GFR) at an early stage has not been well demonstrated. There is growing evidence that utilization of estimated GFR (eGFR) may induce misleading information in a population with near normal renal function. Therefore, a more accurate method is essential.

Methods

A prospective cohort of ADPKD patients was conducted with clinical data and laboratory collection. Measured GFR (mGFR) was assessed by iohexol plasma clearance method using ultra performance liquid chromatography. eGFR was calculated using the CKD-EPI equation. Kidney volumes were evaluated using MRI imaging protocol.

Results

Thirty two patients completed the study. The mean age was 56 years old. The mean initial mGFR was 83.8 mL/min/1.73m². The mean change in mGFR per year was –2.99 mL/min/1.73m²/year. The mean initial height-adjusted TKV (htTKV) was 681.0 mL/m. The mean percentage change in htTKV per year (%ΔhtTKV/y) was 4.77 %/year. mGFR had a better association with clinical parameters than eGFR. Initial mGFR was significantly and inversely correlated with initial htTKV and age. The percentage change in mGFR per year was significantly and inversely correlated with the %ΔhtTKV/y and 24-hr urine albumin. The %ΔhtTKV/y was significantly correlated with initial htTKV.

Conclusions

Our studies demonstrated that mGFR using iohexol is a more reliable and accurate method than eGFR for evaluating GFR changes in the early stages of ADPKD patients. There is a strong inverse correlation between kidney volume and mGFR in an Asian ADPKD population. The initial htTKV is a good predictor of kidney volume progression. The %ΔhtTKV/y is a good early surrogate marker for the decline in renal function. 24-hr urine albumin is also a good indicator for renal progression.

Pain and Obesity in Autosomal Dominant Polycystic Kidney Disease: A Post Hoc Analysis of the Halt Progression of Polycystic Kidney Disease (HALT-PKD) Studies

Rationale & Objective

Pain is a frequent complication of autosomal dominant polycystic kidney disease (ADPKD) and includes back and abdominal pain. We hypothesized that in adults with early- and late-stage ADPKD, overweight and obesity are independently associated with greater self-reported back, abdominal, and radicular pain at baseline and that weight loss would be associated with decreased pain over a follow-up period.

Study Design

Post hoc analysis of pooled data from 2 randomized trials.

Setting & Participants

Participants in the HALT-PKD study A or B. 867 individuals were included in a cross-sectional analysis. 4,248 observations from 871 participants were included in a longitudinal analysis.

Predictor

Overweight and obesity (cross-sectional); annual change in weight as a time-varying predictor (longitudinal).

Outcome

Pain (Likert-scale responses; cross-sectional); annual change in pain (binary outcome of worsening pain or not worsening; longitudinal).

Analytical Approach

Multivariable ordinal logistic regression (cross-sectional); generalized estimating equation analysis (longitudinal).

Results

Participants were aged 42±10 years and baseline estimated glomerular filtration rate was 71±26 mL/min/1.73 m². Back, abdominal, and radicular pain were reported more frequently in individuals with increasing body mass index category (all P < 0.05 for trend). After multivariable adjustment, obesity was associated with increased odds of greater back and radicular pain, but not abdominal pain. Associations remained similar after further adjustment for baseline height-adjusted kidney and liver volume (study A only, n = 457); back pain: OR, 1.88 (95% CI, 1.15-3.08); and radicular pain: OR, 2.92 (95% CI, 1.45-5.91). Longitudinally (median follow-up, 5 years), weight loss (annual decrease in weight ≥ 4%) was associated with decreased adjusted odds of worsening back pain (OR, 0.87 [95% CI, 0.76-0.99]) compared with the reference group (stable weight).

Limitations

Post hoc, associative analysis.

Conclusions

In early- and late-stage ADPKD, obesity was associated with greater back and radicular pain independent of total kidney/liver volume. Mild weight loss was associated with favorable effects on back pain.

Genitourinary Interventions in Autosomal Dominant Polycystic Kidney Disease: Clinical Recommendations for Urologic and Transplant Surgeons

Autosomal dominant polycystic kidney disease is the fourth most common single cause of end-stage renal disease worldwide with both renal and extrarenal manifestations, resulting in significant morbidity. Approaches to the management of this disease vary widely, with no broadly accepted practice guidelines. Herein, we reviewed the various surgical and interventional management options that are targeted toward treating the symptoms or addressing the resulting kidney failure. Novel treatment modalities such as celiac plexus blockade and renal denervation appear to be promising in pain relief; however, further studies are lacking. Renal cyst decortication seems to have a higher success rate in targeting cyst-related pain compared with aspiration only. In terms of requiring major surgical intervention, such as need and timing of native nephrectomy, there are several considerations when deciding on transplantation with or without a pretransplant native nephrectomy. Patients who are not candidates for native nephrectomy may consider transcatheter arterial embolization. Based on our review of the contemporary indications for genitourinary interventions in the management of autosomal dominant polycystic kidney disease, we propose an algorithm that depicts the decision-making process on assessing the indications and timing of native nephrectomy in patients with end-stage renal disease awaiting transplant.

Prostaglandins as potential targets for the treatment of polycystic kidney disease

Polycystic kidney disease (PKD) is characterized by the proliferation of fluid-filled kidney cysts that enlarge over time, causing damage to the surrounding kidney and ultimately resulting in kidney failure. Both increased cell proliferation and fluid secretion are stimulated by increased cyclic adenosine monophosphate (cAMP) in PKD kidneys, so many treatments for the disease target cAMP lowering. Prostaglandins (PG) levels are elevated in multiple animal models of PKD and mediate many of their effects by elevating cAMP levels. Inhibiting the production of PG with cyclooxygenase 2 (COX2) inhibitors reduces PG levels and reduces disease progression. However, COX inhibitors also block beneficial PG and can cause nephrotoxicity. In an orthologous model of the main form of PKD, PGD₂ and PGI₂ were the two PG highest in kidneys and most affected by a COX2 inhibitor. Future studies are needed to determine whether specific blockage of PGD₂ and/or PGI₂ activity would lead to more targeted and effective treatments with fewer undesirable side-effects.

Interventional Approaches for Loin Pain Hematuria Syndrome and Kidney-Related Pain Syndromes

PURPOSE OF REVIEW

Loin pain hematuria syndrome (LPHS) frequently presents with severe chronic pain that poses a clinical challenge. Current treatment approaches are mostly empirical and include a wide range of therapeutic strategies such as physical therapy, local and systemic analgesia, interventional and surgical approaches usually flanked by psycho-behavioral therapy, and other strategies. LPHS often impacts negatively on quality of life particularly in patients who are refractory to treatment.

RECENT FINDINGS

With recent advances in catheter-based treatment approaches and better understanding of the pathophysiology of LPHS, intraluminal renal denervation (RDN) has been proposed as a valuable treatment option for kidney-related pain syndromes. The present review provides a brief overview of the clinical challenges associated with LPHS, highlights recent insights into its underlying mechanisms, and summarizes currently available data on the use of RDN in the context of LPHS and kidney-related pain syndromes. Renal denervation via various approaches including surgical and catheter-based techniques has shown promise in alleviating kidney-related pain syndromes. Randomized controlled trials are now required to better define its role in the management of these conditions.

Prevalence, risk factors and disease knowledge of polycystic kidney disease in Pakistan

Polycystic kidneys disease refers to cyst(s) formation in kidneys with severe consequences of end stage renal disease thus have higher mortality. It is a common genetic disease occurring either as autosomal dominant polycystic kidney (ADPKD) or autosomal recessive polycystic kidney disease (ARPKD) with prevalence rates of 1/1000 and 1/40,000 respectively. Dominant forms presenting in later (>30) while recessive in earlier ages (infancy) and affecting both sexes and almost all race. The patient experiences many renal as well as extra-renal manifestations with marked hypertension and cyst formation in other organs predominantly in liver. Due to genetic basis, positive family history is considered as major risk factor. Ultrasonography remains the main stay of diagnosis along with family history, by indicating increased renal size and architectural modifications. Initially disease remains asymptomatic, later on symptomatic treatment is suggested with surgical interventions like cyst decortications or drainage. Dialysis proved to be beneficial in end stage renal disease. However renal transplantation is the treatment of choice.

Native Nephrectomy before and after Renal Transplantation in Patients with Autosomal Dominant Polycystic Kidney Disease (ADPKD)

The aim of this study was 1) to evaluate and compare pre-, peri-, and post-operative data of Autosomal Dominant Polycystic Kidney Disease (ADPKD) patients undergoing native nephrectomy (NN) either before or after renal transplantation and 2) to identify advantages of optimal surgical timing, postoperative outcomes, and economical aspects in a tertiary transplant centre. This retrospective analysis included 121 patients divided into two groups-group 1: patients who underwent NN prior to receiving a kidney transplant (n = 89) and group 2: patients who underwent NN post-transplant (n = 32). Data analysis was performed according to demographic patient details, surgical indication, laboratory parameters, perioperative complications, underlying pathology, and associated mortality. There was no significant difference in patient demographics between the groups, however right-sided nephrectomy was performed predominantly within group 1. The main indication in both groups undergoing a nephrectomy was pain. Patients among group 2 had no postoperative kidney failure and a significantly shorter hospital stay. Higher rates of more severe complications were observed in group 1, even though this was not statistically significant. Even though the differences between both groups were substantial, the time of NN prior or post-transplant does not seem to affect short-term and long-term transplantation outcomes. Retroperitoneal NN remains a low risk treatment option in patients with symptomatic ADPKD and can be performed either pre- or post-kidney transplantation depending on patients' symptom severity.

Pretransplant Nephrectomy for Large Polycystic Kidneys in ADPKD (Autosomal Dominant Polycystic Kidney Disease) Patients: Is Peritoneal Dialysis Recovery Possible after Surgery?

The choice of modality for renal replacement therapy in patients with ADPKD varies, often based on patient choice, physician-related factors, and resource availability. For a long time peritoneal dialysis (PD) was considered as relative contraindication due to the possible limited intraperitoneal space. In recent years, some studies suggested it is a valid option also in patients with ADPKD to be considered as a first line treatment in potentially fit patients. Diuresis volume lowering and potential permanent damage of peritoneal integrity, both leading to a necessary switch to haemodialysis, are the two most important dangers after nephrectomy, especially if bilateral, in PD patients. We performed a retrospective analysis of patient underwent native polycystic kidney nephrectomy in order to state the possibility to recover peritoneal dialysis after surgery.

Effect of Sirolimus on Native Total Kidney Volume After Transplantation in Patients with Autosomal Dominant Polycystic Kidney Disease: A Randomized Controlled Pilot Study

BACKGROUND

The mammalian target of rapamycin (mTOR) pathway has been shown to be central to cyst formation and growth in patients with autosomal dominant polycystic kidney disease (ADPKD). Drugs that suppress mTOR signaling are frequently used as antiproliferative agents for maintenance immunosuppression in patients who have undergone kidney transplantation. The aim of this study was to determine the effect of sirolimus, an mTOR inhibitor, on cyst volume regression in patients with ADPKD who have undergone renal transplantation.

METHODS

In this single-center, prospective, open-label, parallel-group, randomized trial, 23 adult patients with ADPKD who successfully underwent renal transplantation from 2008 to 2012 were subsequently randomized (on a 1:1 basis) to a maintenance immunosuppression regimen with either sirolimus (sirolimus, tacrolimus, prednisone) or mycophenolate (mycophenolate, tacrolimus, prednisone). Total kidney volumes were measured by means of high-resolution magnetic resonance imaging within 2 weeks after transplantation and at 1 year. The primary end point was change in total kidney volume at 1 year.

RESULTS

Sixteen patients completed the 1-year study (8 patients in each group). There was a decrease in kidney volume in both the sirolimus group (percentage change from baseline, 20.5%; P < .001) and mycophenolate group (percentage change from baseline, 17%; P = .048), but there was no significant difference in percentage change of total kidney volume between the groups (P = .665).

CONCLUSIONS

In ADPKD patients at 1 year after kidney transplantation, there was a similar decrease in polycystic kidney volume in patients receiving an immunosuppression regimen containing sirolimus compared with patients receiving mycophenolate.

Effect of renal transcatheter arterial embolization on quality of life in patients with autosomal dominant polycystic kidney disease

Background

Currently, there are few strategies for improving the quality of life (QOL) in patients with autosomal dominant polycystic kidney disease (ADPKD) and massive kidneys. Renal transcatheter arterial embolization (TAE) reduces kidney volume, but its impact on QOL in ADPKD patients on hemodialysis is unknown. This study investigated the influence of renal TAE on QOL in ADPKD patients with massive kidneys receiving hemodialysis.

Methods

This prospective observational study enrolled 188 ADPKD patients on hemodialysis (92 men and 96 women; mean age 56.7 ± 9.1 years) who underwent renal TAE at Toranomon Hospital between August 2010 and July 2014. The 36-item Short Form Health Survey (SF-36) and our original 15-item questionnaire were used to evaluate QOL.

Results

Using a linear mixed model, the least squares mean values of the SF-36 physical component summary (PCS), mental component summary (MCS) and role/social component summary (RCS) before renal TAE were calculated as 38.21 [95% confidence interval (CI) 36.50-39.91], 48.45 (47.05-49.86) and 43.04 (40.70-45.37), respectively. These values improved to 42.0 (40.22-43.77; P < 0.001 versus before TAE), 51.25 (49.78-52.71; P = 0.001) and 49.67 (47.22-52.12; P < 0.001), respectively, 1 year after renal TAE. Scores for abdominal fullness, poor appetite and heartburn showed marked improvement after renal TAE, while scores for fever, bodily pain and sleep disorder also improved slightly, but significantly. Scores for constipation and use of analgesics/sleeping medications/laxatives did not improve significantly. All of the SF-36 scores and the scores for specific symptoms (except bodily pain, snoring and constipation) were significantly correlated with the sequential decrease of the height-adjusted total kidney volume.

Conclusions

In ADPKD patients on hemodialysis, renal TAE was effective in improving abdominal fullness, appetite, heartburn and SF-36 scores (MCS and RCS scores), but not for sleep disturbance, constipation and physical strength (PCS score).

Large Retroperitoneal Haemorrhage Following Cyst Rupture in a Patient with Autosomal Dominant Polycystic Kidney Disease

The complications of autosomal dominant polycystic kidney disease (ADPKD) include cyst rupture and haemorrhage leading to loin pain and frank haematuria. Risk factors include large kidney volume, hypertension, and renal impairment. We present a case of a young male who, following trauma to the kidney, had a life threatening bleed from his polycystic kidney. The case was initially treated with fluid resuscitation and blood transfusion but necessitated radiological embolization of bleeding source to control the blood loss. We review the risk factors and management of cyst haemorrhage in patients with ADPKD. Contact sports should be avoided as cyst rupture can lead to severe life threatening haemorrhage.

Hepatointestinal complications in polycystic kidney disease

Background

The objective of this study was to determine the incidence of major hepatointestinal complications in patients with polycystic kidney disease (PKD).

Methods

We analyzed the Taiwan National Health Insurance claims data (2000-2010) of 6031 patients with PKD and 23,976 non-PKD hospitalized controls. The control cohort was propensity score matched with the PKD cohort at a 1:4 ratio. All patients were followed up from the index date to the first inpatient diagnosis of hepatointestinal complications, death, or 31 December, 2011. Cox proportional hazard regression models were used to identify the risk of outcome after adjustment for potential confounders.

Results

The incidence rates of acute pancreatitis, cholangitis, peptic ulcer bleeding, and cirrhosis were 5.72, 4.01, 19.9, and 5.46 per 1000 person-years, respectively, in the PKD cohort. Compared with the non-PKD controls, patients with PKD exhibited an increased risk of hospitalization for acute pancreatitis, cholangitis, peptic ulcer bleeding, and cirrhosis (adjusted subhazard ratio [aSHR]: 2.36, 95% confidence interval [95% CI], 1.95-2.84]; 2.36, [95% CI, 1.95-2.84]; 2.41, [95% CI, 1.93-3.01]; 2.41, [95% CI, 2.17-2.67]; and 1.39, [95% CI, 1.16-1.66], respectively; all p < 0.001). PKD, chronic kidney disease, and alcoholism were independent predictors of all these hepatointestinal complications. Kaplan-Meier analysis revealed an increased overall mortality in patients with PKD who developed acute pancreatitis and peptic ulcer bleeding (log-rank p < 0.05).

Conclusion

PKD is associated with clinically significant extrarenal complications including acute pancreatitis, cholangitis, peptic ulcer bleeding, and cirrhosis.

Neonatal renal cystic diseases

PURPOSE

Neonatal renal cystic diseases have a great impact on the morbidity and mortality of the affected neonates and infants. A good insight into the pathophysiology, diagnosis and treatment options of various neonatal renal cystic diseases aid in early diagnosis and intervention, thereby preventing complications.

METHODS

PubMed search was done for articles on "neonatal renal cystic diseases" and relevant publications including reviews were considered for our article.

RESULTS

Both hereditary and nonhereditary causes of cystic kidney diseases can result in severe morbidity and mortality. The main diagnostic modality is ultrasound imaging and most of the neonatal renal cystic diseases are detected during prenatal ultrasound screening. Commonly encountered neonatal renal cystic diseases are autosomal dominant polycystic kidney disease, autosomal recessive polycystic kidney disease and multicystic dysplastic kidney.

CONCLUSIONS

A thorough knowledge of various renal cystic diseases can be of extreme prognostic value. Physicians should be aware of the impact of early diagnosis and intervention on the lives of those affected. Further research about treatment of these diseases is ongoing and can result in breakthrough therapies for these patients.

Novel treatment protocol for ameliorating refractory, chronic pain in patients with autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) patients can suffer from chronic pain that can be refractory to conventional treatment, resulting in a wish for nephrectomy. This study aimed to evaluate the effect of a multidisciplinary treatment protocol with sequential nerve blocks on pain relief in ADPKD patients with refractory chronic pain. As a first step a diagnostic, temporary celiac plexus block with local anesthetics was performed. If substantial pain relief was obtained, the assumption was that pain was relayed via the celiac plexus and major splanchnic nerves. When pain recurred, patients were then scheduled for a major splanchnic nerve block with radiofrequency ablation. In cases with no pain relief, it was assumed that pain was relayed via the aortico-renal plexus, and catheter-based renal denervation was performed. Sixty patients were referred, of which 44 were eligible. In 36 patients the diagnostic celiac plexus block resulted in substantial pain relief with a change in the median visual analogue scale (VAS) score pre-post intervention of 50/100. Of these patients, 23 received a major splanchnic nerve block because pain recurred, with a change in median VAS pre-post block of 53/100. In 8 patients without pain relief after the diagnostic block, renal denervation was performed in 5, with a borderline significant change in the median VAS pre-post intervention of 20/100. After a median follow-up of 12 months, 81.8% of the patients experienced a sustained improvement in pain intensity, indicating that our treatment protocol is effective in obtaining pain relief in ADPKD patients with refractory chronic pain.

Tolvaptan and Kidney Pain in Patients With Autosomal Dominant Polycystic Kidney Disease: Secondary Analysis From a Randomized Controlled Trial

Background

Kidney pain is a common complication in patients with autosomal dominant polycystic kidney disease (ADPKD), and data from the TEMPO 3:4 trial suggested that tolvaptan, a vasopressin V2 receptor antagonist, may have a positive effect on kidney pain in this patient group. Because pain is difficult to measure, the incidence of kidney pain leading to objective medical interventions was used in the present study to assess pain.

Study Design

Secondary analysis from a randomized controlled trial.

Setting & Participants

Patients with ADPKD with preserved kidney function.

Intervention

Tolvaptan or placebo.

Outcomes

Kidney pain events defined by objective medical interventions.

Measurements

Kidney pain events were recorded and independently adjudicated. Incidence of a first kidney pain event was assessed overall and categorized into 5 subgroups according to severity.

Results

Of 1,445 participating patients (48.4% women; mean age, 39 ± 7 [SD] years; mean estimated glomerular filtration rate, 81 ± 22 mL/min/1.73 m²; median total kidney volume, 1,692 [IQR, 750–7,555] mL), 50.9% reported a history of kidney pain at baseline. History of urinary tract infections, kidney stones, or hematuria (all P < 0.001) and female sex (P < 0.001) were significantly associated with history of kidney pain. Tolvaptan use resulted in a significantly lower incidence of kidney pain events when compared to placebo: 10.1% versus 16.8% (P < 0.001), with a risk reduction of 36% (HR, 0.64; 95% CI, 0.48–0.86). The reduction in pain event incidence by tolvaptan was found in all groups irrespective of pain severity and was independent of predisposing factors (P for interaction > 0.05). The effect of tolvaptan was explained at least in part by a decrease in incidence of urinary tract infections, kidney stones, and hematuria when compared to placebo.

Limitations

Trial has specific inclusion criteria for total kidney volume and kidney function.

Conclusions

Tolvaptan decreased the incidence of kidney pain events independent of patient characteristics predisposing for kidney pain and possibly in part due to reductions in ADPKD-related complications.

Intracystic magnetic resonance imaging in patients with autosomal dominant polycystic kidney disease: features of severe cyst infection in a case-control study

Background

The purpose of this study was to investigate the usefulness of intracystic MRI features for detection of severe cyst infection that is usually refractory to antibiotic therapy alone in patients with autosomal dominant polycystic kidney disease.

Methods

Seventy-six patients (88 episodes) with positive cyst cultures treated from January 2006 to December 2013 were enrolled as the cases for this case–control study, while 147 patients who continued to attend our hospital from January 2011 to December 2013 and did not have cyst infection diagnosed during that period were enrolled as the controls. Intracystic MRI findings were investigated.

Results

At least one of four intracystic MRI features (high signal intensity (SI) on diffusion-weighted images (DWI), fluid-fluid level, wall thickening, or gas) was found in all of the cases, but such findings were also detected in some controls. Intracystic gas was specific for cyst infection, but its sensitivity was only 1.1 %. A high intracystic SI on DWI showed a sensitivity of 86.4 %, but its specificity was lower at 33.3 %. Both the specificity and sensitivity of a fluid-fluid level or wall thickening were about 80 %. However, the specificity of these MRI features decreased as total liver and kidney volume (TLKV) increased, falling to 65.8 % in patients with organomegaly (TLKV > 8500 cm³). A cyst diameter > 5 cm was useful for detecting severely infected cysts that needed drainage, and specificity was increased by combining the other four MRI findings with a cyst diameter > 5 cm.

Conclusions

MRI with DWI was useful for detecting severe cyst infection in ADPKD. While the specificity of MRI alone was not high enough in patients with organomegaly, combining the four MRI features with abdominal pain, sequential MRI changes, or cyst diameter > 5 cm improved detection of severely infected cysts in these patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-016-0381-9) contains supplementary material, which is available to authorized users.

[Polycystic kidney disease and kidney transplantation]

OBJECTIVES

To perform a state of the art about autosomal dominant polykystic kidney disease (ADPKD), management of its urological complications and end stage renal disease treatment modalities.

MATERIAL AND METHODS

An exhaustive systematic review of the scientific literature was performed in the Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of the following keywords (MESH): "autosomal dominant polykystic kidney disease", "complications", "native nephrectomy", "kidney transplantation". Publications obtained were selected based on methodology, language, date of publication (last 10 years) and relevance. Prospective and retrospective studies, in English or French, review articles; meta-analysis and guidelines were selected and analyzed. This search found 3779 articles. After reading titles and abstracts, 52 were included in the text, based on their relevance.

RESULTS

ADPKD is the most inherited renal disease, leading to end stage renal disease requiring dialysis or renal transplantation in about 50% of the patients. Many urological complications (gross hematuria, cysts infection, renal pain, lithiasis) of ADPKD required urological management. The pretransplant evaluation will ask the challenging question of native nephrectomy only in case of recurrent kidney complications or large kidney not allowing graft implantation. The optimum timing for native nephrectomy will depend on many factors (dialysis or preemptive transplantation, complication severity, anuria, easy access to transplantation, potential living donor).

CONCLUSION

Pretransplant management of ADPKD is challenging. A conservative strategy should be promoted to avoid anuria (and its metabolic complications) and to preserve a functioning low urinary tract and quality of life. When native nephrectomy should be performed, surgery remains the gold standard but renal arterial embolization may be a safe option due to its low morbidity.

On the Origin of Interoception

Over the course of a century, the meaning of interoception has changed from the restrictive to the inclusive. In its inclusive sense, it bears relevance to every individual via its link to emotion, decision making, time-perception, health, pain, and various other areas of life. While the label for the perception of the body state changes over time, the need for an overarching concept remains. Many aspects can make any particular interoceptive sensation unique and distinct from any other interoceptive sensation. This can range from the sense of agency, to the physical cause of a sensation, the ontogenetic origin, the efferent innervation, and afferent pathways of the tissue involved amongst others. In its overarching meaning, interoception primarily is a product of the central nervous system, a construct based on an integration of various sources, not per se including afferent information. This paper proposes a definition of interoception as based on subjective experience, and pleas for the use of specific vocabulary in addressing the many aspects that contribute to it.

Long-term functional results of aspiration and sclerotherapy with ethanol in patients with autosomal dominant polycystic kidney disease: a non-randomized pilot clinical study

PURPOSE

To evaluate the long-term effect of aspiration and sclerotherapy treatment on the pain control, blood pressure regulation, and quality of life (QoL) in patients with autosomal dominant polycystic disease (ADPKD).

METHODS

Twenty-five ADPKD patients with a total of 32 dominant cysts were treated with ultrasound guidance percutaneous aspiration and 96% ethanol injection, between 2002 and 2014. Twenty-one dominant cysts of 16 patients who had a minimum of 10-year follow-up were included in this study. The level of pain [visual analog score (VAS)], narcotic usage, blood pressure and serum creatinine level, QoL questionnaire, and radiological dominant cyst size was evaluated before and after procedure, retrospectively.

RESULTS

The mean dominant cyst size was even smaller after follow-up of 10 years. Mean dominant cyst size was 7.2 ± 2.3 cm before the procedure and 0.9 ± 0.9 and 3.3 ± 1.2 cm after the one- and 10-year follow-ups, respectively (p < 0.05). VAS and QoL scores were improved after 10 years of follow-up. There was no relation between cyst size and VAS score as well as QoL questionnaire score. End-stage renal disease occurred in 50%, and there was no significant improvement in blood pressure of these patients.

CONCLUSIONS

Aspiration and sclerotherapy with ethanol is a minimal-invasive, safe, and inexpensive outpatient treatment method with acceptable short- and long-term results in ADPKD patients. Aspiration and sclerotherapy with ethanol can be an option for patients with ADPKD.

Current management of autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD), the most frequent cause of genetic renal disease affecting approximately 4 to 7 million individuals worldwide and accounting for 7%-15% of patients on renal replacement therapy, is a systemic disorder mainly involving the kidney but cysts can also occur in other organs such as the liver, pancreas, arachnoid membrane and seminal vesicles. Though computed tomography and magnetic resonance imaging (MRI) were similar in evaluating 81% of cystic lesions of the kidney, MRI may depict septa, wall thickening or enhancement leading to upgrade in cyst classification that can affect management. A screening strategy for intracranial aneurysms would provide 1.0 additional year of life without neurological disability to a 20-year-old patient with ADPKD and reduce the financial impact on society of the disease. Current treatment strategies include reducing: cyclic adenosine monophosphate levels, cell proliferation and fluid secretion. Several randomised clinical trials (RCT) including mammalian target of rapamycin inhibitors, somatostatin analogues and a vasopressin V2 receptor antagonist have been performed to study the effect of diverse drugs on growth of renal and hepatic cysts, and on deterioration of renal function. Prophylactic native nephrectomy is indicated in patients with a history of cyst infection or recurrent haemorrhage or to those in whom space must be made to implant the graft. The absence of large RCT on various aspects of the disease and its treatment leaves considerable uncertainty and ambiguity in many aspects of ADPKD patient care as it relates to end stage renal disease (ESRD). The outlook of patients with ADPKD is improving and is in fact much better than that for patients in ESRD due to other causes. This review highlights the need for well-structured RCTs as a first step towards trying newer interventions so as to develop updated clinical management guidelines.

Autosomal-dominant polycystic kidney disease (ADPKD): executive summary from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Autosomal-dominant polycystic kidney disease (ADPKD) affects up to 12 million individuals and is the fourth most common cause for renal replacement therapy worldwide. There have been many recent advances in the understanding of its molecular genetics and biology, and in the diagnosis and management of its manifestations. Yet, diagnosis, evaluation, prevention, and treatment vary widely and there are no broadly accepted practice guidelines. Barriers to translation of basic science breakthroughs to clinical care exist, with considerable heterogeneity across countries. The Kidney Disease: Improving Global Outcomes Controversies Conference on ADPKD brought together a panel of multidisciplinary clinical expertise and engaged patients to identify areas of consensus, gaps in knowledge, and research and health-care priorities related to diagnosis; monitoring of kidney disease progression; management of hypertension, renal function decline and complications; end-stage renal disease; extrarenal complications; and practical integrated patient support. These are summarized in this review.

Laparoscopic Nephrectomy versus Open Nephrectomy for Patients with Autosomal Dominant Polycystic Kidney Disease: A Systematic Review and Meta-Analysis

Objective

To compare efficacy and safety of laparoscopicnephrectomy (LN) versusopen nephrectomy (ON) in the management of autosomal dominant polycystic kidney disease (ADPKD), we conducted a systematic review and meta-analysis.

Methods

A systematic search of the electronic databases PubMed, Scopus, and the Cochrane Library was performed up to October 2014.This systematic review was performed based on observational comparative studies that assessed the two techniques. The weighted mean difference (WMD) and risk ratio (RR), with their corresponding 95% confidence interval (CI), were calculated to compare continuous and dichotomous variables, respectively.

Results

Seven studies were identified, including 195 cases (118 LN / 77 ON). Although LN was associated with longer operative time (WMD 30.236, 95%CI 14.541 −45.932, P<0.001) and the specimen might not have been resected as heavy as the ON group (WMD -986.516, 95%CI -1883.24–-89.795, P = 0.031), patients in this group might benefit from a shorter length of hospital stay (WMD -3.576, 95%CI 4.976–-2.176, P <0.001), less estimated blood loss (WMD -180.245, 95%CI -317.939–-42.556, P = 0.010), and lower need of transfusion (RR 0.345, 95%CI 0.183–0.650, P = 0.001). The LN group also had less overall complications (RR 0.545, 95%CI 0.329–0.903, P = 0.018). The need of narcotic analgesics between the two groups might have no significant difference (WMD -54.66, 95%CI -129.76–20.44, P = 0.154).

Conclusion

LN for giant symptomatic ADPKD was feasible, safe and efficacious. Morbidity was significantly reduced compared with the open approach. For an experienced laparoscopist, LN might be a better alternative.

Total Kidney Volume in Autosomal Dominant Polycystic Kidney Disease: A Biomarker of Disease Progression and Therapeutic Efficacy

Autosomal dominant polycystic kidney disease (ADPKD) is the most common potentially life-threatening monogenic disorder in humans, characterized by progressive development and expansion of fluid-filled cysts in the kidneys and other organs. Ongoing cyst growth leads to progressive kidney enlargement, whereas kidney function remains stable for decades as a result of hyperfiltration and compensation by unaffected nephrons. Kidney function irreversibly declines only in the late stages of the disease, when most of the parenchyma is lost to cystic and fibrotic tissue and the remaining compensatory capacity is overwhelmed. Hence, conventional kidney function measures, such as glomerular filtration rate, do not adequately assess disease progression in ADPKD, especially in its early stages. Given the recent development of potential targeted therapies in ADPKD, it has become critically important to identify relevant biomarkers that can be used to determine the degree of disease progression and evaluate the effects of therapeutic interventions on the course of the disease. We review the current evidence to provide an informed perspective on whether total kidney volume (TKV) is a suitable biomarker for disease progression and whether TKV can be used as an efficacy end point in clinical trials. We conclude that because cystogenesis is the central factor leading to kidney enlargement, TKV appears to be an appropriate biomarker and is gaining wider acceptance. Several studies have identified TKV as a relevant imaging biomarker for monitoring and predicting disease progression and support its use as a prognostic end point in clinical trials.

A painful inheritance-patient perspectives on living with polycystic kidney disease: thematic synthesis of qualitative research

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) is a life-threatening genetic disorder and has multiple complications including, infection, pain, intracranial aneurysm and kidney failure leading to significantly impaired quality of life and reduced survival. These outcomes are well described, but patient perspectives and experiences of living with ADPKD are under-recognized.

METHODS

MEDLINE, Embase, PsycINFO and CINAHL were searched to August 2014. Studies were analyzed using thematic synthesis.

RESULTS

From 21 studies (n = 247), we derived five themes: unvalidated pain (medical trivialization, inadequacy of pain management); persisting uncertainties and ambiguities (lacking diagnostic clarity, disempowerment in self-care, unpredictable daily disruptions, inability to plan ahead, financial discrimination); genetic guilt and resentment (blaming parents, self-blame, constant burden of guilt); precariousness in pursuing parenthood (prognostic uncertainty, owning the decision, needing directive counselling); and defining parental responsibility for genetic testing and disclosure (preserving normality, doubting necessity of genetic testing, respecting the child's autonomy and hope in future technologies, facilitating preparedness).

CONCLUSIONS

The erratic onset of pain contributes to the substantial unpredictability of daily living and prevents patients from establishing long-term life goals. Decisions about family planning, genetic testing of children and disclosure involves making profoundly difficult judgments about ethical parental responsibility. Patient engagement in pain management, strategies for self-care, counselling to reduce the burden of 'genetic guilt' and specific family planning decision support tools may be priorities for care to improve patient-centred outcomes in ADPKD.

Management of pain in autosomal dominant polycystic kidney disease and anatomy of renal innervation

PURPOSE

Chronic pain is a prominent feature of autosomal dominant polycystic kidney disease that is difficult to treat and manage, often resulting in a decrease in quality of life. Understanding the underlying anatomy of renal innervation and the various etiologies of pain that occur in autosomal dominant polycystic kidney disease can help guide proper treatments to manage pain. Reviewing previously studied treatments for pain in autosomal dominant polycystic kidney disease can help characterize treatment in a stepwise fashion.

MATERIALS AND METHODS

We performed a literature search of the etiology and management of pain in autosomal dominant polycystic kidney disease and the anatomy of renal innervation using PubMed® and Embase® from January 1985 to April 2014 with limitations to human studies and English language.

RESULTS

Pain occurs in the majority of patients with autosomal dominant polycystic kidney disease due to renal, hepatic and mechanical origins. Patients may experience different types of pain which can make it difficult to clinically confirm its etiology. An anatomical and histological evaluation of the complex renal innervation helps in understanding the mechanisms that can lead to renal pain. Understanding the complex nature of renal innervation is essential for surgeons to perform renal denervation. The management of pain in autosomal dominant polycystic kidney disease should be approached in a stepwise fashion. Acute causes of renal pain must first be ruled out due to the high incidence in autosomal dominant polycystic kidney disease. For chronic pain, nonopioid analgesics and conservative interventions can be used first, before opioid analgesics are considered. If pain continues there are surgical interventions such as renal cyst decortication, renal denervation and nephrectomy that can target pain produced by renal or hepatic cysts.

CONCLUSIONS

Chronic pain in patients with autosomal dominant polycystic kidney disease is often refractory to conservative, medical and other noninvasive treatments. There are effective surgical procedures that can be performed when more conservative treatments fail. Laparoscopic cyst decortication has been well studied and results in the relief of chronic renal pain in the majority of patients. In addition, renal denervation has been used successfully and could be performed concurrently with cyst decortication. Nephrectomy should be reserved for patients with intractable pain and renal failure when other modalities have failed.

A stepwise approach for effective management of chronic pain in autosomal-dominant polycystic kidney disease

Chronic pain, defined as pain existing for >4-6 weeks, affects >60% of patients with autosomal-dominant polycystic disease (ADPKD). It can have various causes, indirectly or directly related to the increase in kidney and liver volume in these patients. Chronic pain in ADPKD patients is often severe, impacting physical activity and social relationships, and frequently difficult to manage. This review provides an overview of pathophysiological mechanisms that can lead to pain and discusses the sensory innervation of the kidneys and the upper abdominal organs, including the liver. In addition, the results of a systematic literature search of ADPKD-specific treatment options are presented. Based on pathophysiological knowledge and evidence derived from the literature an argumentative stepwise approach for effective management of chronic pain in ADPKD is proposed.

Chronic kidney pain in autosomal dominant polycystic kidney disease: a case report of successful treatment by catheter-based renal denervation

Chronic pain is a common concern in patients with autosomal dominant polycystic kidney disease (ADPKD). We report what to our knowledge is the first catheter-based renal denervation procedure in a patient with ADPKD resulting in successful management of chronic pain. The patient was a 43-year-old woman whose chronic pain could not be controlled by pain medication or splanchnic nerve blockade. Transluminal radiofrequency renal denervation was performed as an experimental therapeutic option with an excellent result, indicating that this procedure should be considered for chronic pain management in ADPKD.

The TRPP subfamily and polycystin-1 proteins

It has been exciting times since the identification of polycystic kidney disease 1 (PKD1) and PKD2 as the genes mutated in autosomal dominant polycystic kidney disease (ADPKD). Biological roles of the encoded proteins polycystin-1 and TRPP2 have been deduced from phenotypes in ADPKD patients, but recent insights from vertebrate and invertebrate model organisms have significantly expanded our understanding of the physiological functions of these proteins. The identification of additional TRPP (TRPP3 and TRPP5) and polycystin-1-like proteins (PKD1L1, PKD1L2, PKD1L3, and PKDREJ) has added yet another layer of complexity to these fascinating cellular signalling units. TRPP proteins assemble with polycystin-1 family members to form receptor-channel complexes. These protein modules have important biological roles ranging from tubular morphogenesis to determination of left-right asymmetry. The founding members of the polycystin family, TRPP2 and polycystin-1, are a prime example of how studying human disease genes can provide insights into fundamental biological mechanisms using a so-called "reverse translational" approach (from bedside to bench). Here, we discuss the current literature on TRPP ion channels and polycystin-1 family proteins including expression, structure, physical interactions, physiology, and lessons from animal model systems and human disease.

Renal transplantation and polycystic: surgical considerations

BACKGROUND

The indication and timing of nephrectomy in patients with autosomal dominant polycystic kidney disease (ADPKD) remain controversial, especially in patients who are candidates to renal transplantation (RT). The main surgical options such as unilateral vs. bilateral nephrectomy, nephrectomy before vs. after RT, or simultaneous nephrectomy and transplantation, are herein discussed.

OBJECTIVE

Evidence acquisition of the best surgical management available for ADPKD in the context of kidney transplantation.

ACQUISITION OF EVIDENCE

Systematic literature review in PubMed from 1978 to 2013 was conducted. Articles selected included:randomized controlled trials and cohort studies. Furthermore, well designed ADPKD reviews were considered for this study.

SYNTHESIS OF EVIDENCE

Laparoscopic nephrectomy in ADPKD is a safe procedure with an acceptable complication rate. Unilateral nephrectomy has advantages over the bilateral one regarding the perioperative complication rate. Although the timing of nephrectomy is controversial, it seems that simultaneous nephrectomy and renal transplantation does not increase surgical morbidity neither affect graft survival.

CONCLUSIONS

Simultaneous nephrectomy and RT appears to be an acceptable alternative to conventional two-stage procedure without any increased morbidity, in the context of ADPKD. Furthermore, laparoscopic nephrectomy performed in experienced centres is a safe alternative to conventional approach.