Kidney Disease Improving Global Outcomes guidelines and parathyroidectomy for renal hyperparathyroidism

Dialysis for Chronic Kidney Failure: A Review

Importance

More than 3.5 million people worldwide and 540 000 individuals in the US receive maintenance hemodialysis or peritoneal dialysis for the treatment of chronic kidney failure. The 5-year survival rate is approximately 40% after initiation of maintenance dialysis.

Observations

Hemodialysis and peritoneal dialysis remove metabolic waste and excess body water and rebalance electrolytes to sustain life. There is no recommended estimated glomerular filtration rate (eGFR) threshold for initiating dialysis, and patient-clinician shared decision-making should help determine when to initiate dialysis. Persistent signs and symptoms of uremia (eg, nausea, fatigue) and volume overload (eg, dyspnea, peripheral edema), worsening eGFR, metabolic acidosis, and hyperkalemia inform the timing of therapy initiation. A randomized clinical trial reported no mortality benefit to starting dialysis at higher eGFR (10-14 mL/min/1.73 m2) vs lower eGFR (5-7 mL/min/1.73 m2) levels. Observational data suggested no differences in 5-year mortality with use of hemodialysis vs peritoneal dialysis. Cardiovascular (eg, arrhythmias, cardiac arrest) and infection-related complications of maintenance dialysis are common. In the US, hemodialysis catheter-related bloodstream infections occur at a rate of 1.1 to 5.5 episodes per 1000 catheter-days and affect approximately 50% of patients within 6 months of catheter placement. Peritonitis occurs at a rate of 0.26 episodes per patient-year and affects about 30% of individuals in the first year of peritoneal dialysis therapy. Chronic kidney failure-related systemic complications, such as anemia, hyperphosphatemia, hypocalcemia, and hypertension, often require pharmacologic treatment. Hypotension during dialysis, refractory symptoms (eg, muscle cramps, itching), and malfunction of dialysis access can interfere with delivery of dialysis.

Conclusions and Relevance

In 2021, more than 540 000 patients in the US received maintenance hemodialysis or peritoneal dialysis for treatment of chronic kidney failure. Five-year survival rate after initiation of maintenance dialysis is approximately 40%, and the mortality rate is similar with hemodialysis and peritoneal dialysis. Decisions about dialysis initiation timing and modality are influenced by patient symptoms, laboratory trajectories, patient preferences, and therapy cost and availability and should include shared decision-making.

18F-Fluorocholine PET/CT Compared with Current Imaging Procedures for Preoperative Localization of Hyperfunctioning Parathyroids in Patients with Chronic Kidney Disease

Hyperparathyroidism (HPT) in patients with chronic kidney disease (CKD) includes secondary (sHPT) and tertiary hyperparathyroidism (tHPT). Considering that the role of preoperative imaging in the clinical setting is controversial, in the present study we have retrospectively compared pre-surgical diagnostic performances of ¹⁸F-Fluorocholine (¹⁸F-FCH) PET/CT, cervical ultrasonography (US), parathyroid scintigraphy, and 4D-CT in a group of 30 patients with CKD and HPT (18/12 sHPT/tHPT), 21 CKD G5 including 18 in dialysis, and 9 kidney transplant recipients. All patients underwent ¹⁸F-FCH, and 22 had cervical US, 12 had parathyroid scintigraphy, and 11 had 4D-CT. Histopathology was the gold standard. Seventy-four parathyroids were removed: 65 hyperplasia, 6 adenomas, and 3 normal glands. In the whole population, in a per gland analysis, ¹⁸F-FCH PET/CT was significantly more sensitive and accurate (72%, 71%) than neck US (25%, 43%), parathyroid scintigraphy (35%, 47%), and 4D-CT (40%, 47%). The specificity of ¹⁸F-FCH PET/CT (69%) was lower than that of neck US (95%) and parathyroid scintigraphy (90%), without, however, achieving significance. ¹⁸F-FCH PET/CT was more accurate than all other diagnostic techniques when sHPT and tHPT patients were considered separately. ¹⁸F-FCH PET/CT sensitivity was significantly higher in tHPT (88%) than in sHPT (66%). Three ectopic hyperfunctioning glands (in three different patients) were all detected by ¹⁸F-FCH PET/CT, two by parathyroid scintigraphy, and none by cervical US and 4D-CT. Our study confirms that ¹⁸F-FCH PET/CT is an effective preoperative imaging option in patients with CKD and HPT. These findings may be of greater importance in patients with tHPT (who could benefit from minimally invasive parathyroidectomy) than in patients with sHPT, who often undergo bilateral cervicotomy. In these cases, preoperative ¹⁸F-FCH PET/CT may be helpful in locating ectopic glands and may guide the surgical choice for gland preservation.

[Evolution of the incidence and results at 12 months of parathyroidectomy: 40 years of experience in a dialysis center with two successive surgical departments]

INTRODUCTION

Secondary hyperparathyroidism remains the main complication of mineral and bone metabolism in patients with chronic kidney disease. In case of resistance to medical treatment (native and active vitamin D, calcium and calcimimetics), surgical parathyroidectomy is indicated. The aim of this retrospective study is to show the evolution of the incidence and results of surgical parathyroidectomy in our center between 1980 and 2020 as patient characteristics, diagnostic and therapeutic strategies have changed.

PATIENTS AND METHODS

We collected data from dialysis patients who had a first surgical parathyroidectomy between 2000 and 2020 (period 2) in the same surgical department and compared them with historical data between 1980 and 1999 (period 1) operated in one other center.

RESULTS

In period 1, 53 surgical parathyroidectomy were performed (2.78/year, 0 to 5, 8.5/1000 patients-year) vs.56 surgical parathyroidectomy in period 2 (2.8/year, 0 to 9, 8/1000 patients-year). The patients of the 2 periods were comparable except for the higher dialysis vintage in period 1 (149±170 vs.89±94 months; P=0.02). In comparison with dialysis patients not requiring surgical parathyroidectomy during the same period, patients who had surgical parathyroidectomy were younger, had higher dialysis vintage and lower diabetes prevalence, but more frequently carriers of glomerulopathy or polycystosis. Systematically performed in period 2, cervical ultrasound identified at least one visible gland in 78.6% of cases while the scintigraphy, performed only in 66% of cases, found at least one gland in 81% of cases. Twelve months after surgery, PTH > 300 pg/mL (marker of secondary hyperparathyroidism recurrence or surgery failure) was present in 30% of patients in period 1 vs. 5.3% in period 2. Hypoparathyroidism was also more frequently observed in period 2 (35.7 vs. 18.8%). Surgical complications were also higher in period 1.

CONCLUSION

Despite therapeutic and strategic advances, severe secondary hyperparathyroidism is still as common as ever. It is favored by excessively high PTH targets, by suboptimal prevention before dialysis and poor tolerance of calcimimetics. The surgical parathyroidectomy is effective and safe in the hands of a specialized team with an ultrasound and scintigraphic preoperative assessment.

Outcomes following parathyroidectomy for secondary hyperparathyroidism in patients with chronic kidney disease - a single-centre study

BACKGROUND

Surgical parathyroidectomy may be required for severe and refractory secondary hyperparathyroidism (SHPT) in patients with chronic kidney disease (CKD). Parathyroidectomy is associated with long-term survival benefit despite an increase in short-term morbidity and mortality. Global variation in practice exists, with limited Australian data on outcomes following parathyroidectomy.

METHODS

We conducted a retrospective study of patients who underwent parathyroidectomy for SHPT between January 2010 and December 2019 at a single tertiary referral centre in Melbourne, Australia. Biochemical markers and medications were assessed 12 months pre- and post-surgery. Clinical outcomes, including hospital readmission, cardiovascular events and mortality were assessed following surgery.

RESULTS

During the 10-year study period, 129 patients underwent parathyroidectomy for SHPT (mean age 50.7 ± 15 years, 109 (85%) on dialysis). Significant immediate post-operative complications were seen in eight patients (6%), requiring admission to the intensive care unit (n = 6) or return to theatre (n = 2). Within the first 6 months, 24 patients (19%) required hospital readmission. Within 12 months post-parathyroidectomy, 100 (78%) and 103 patients (80%) experienced at least one episode of hypercalcaemia (corrected calcium >2.6 mmol/L) or hypocalcaemia (corrected calcium <2.1 mmol/L) respectively. Over a 12-month period there were six deaths (5%), and eight patients (6%) experienced a major cardiovascular event.

CONCLUSION

Significant fluctuations in serum calcium levels are common post-parathyroidectomy, however long-term morbidity and mortality in our cohort were lower than previously reported, highlighting that parathyroidectomy in a carefully selected cohort is safe for severe SHPT refractory to medical treatment. This article is protected by copyright. All rights reserved.

Safety and effectiveness of reoperation for persistent or recurrent drug refractory secondary hyperparathyroidism

Background

Drug-refractory secondary hyperparathyroidism (SHPT) is the most common complication in patients with chronic renal failure (CRF). Although surgery is the most effective and safe method for drug-refractory SHPT, the condition may persist or recur after the primary surgery, and reoperation is often required in these patients. The purpose of our current study was to evaluate the safety and effectiveness of reoperation for drug-refractory SHPT.

Methods

The clinical data of 15 patients requiring reoperation after a surgery for drug-refractory SHPT in our hospital from 2010 to 2019 were retrospectively analyzed. Changes in biochemical markers including intact parathyroid hormone (iPTH), blood calcium (Ca), blood phosphorus (P), alkaline phosphatase (ALP), and blood calcium phosphorus product (Ca*P) were compared before and after the surgery, and the effectiveness and complications of the reoperation were summarized.

Results

The reoperation was successful in all the 15 patients after a single attempt. Routine pathological examinations identified a total of 25 parathyroid glands, of which 10 were in the neck in situ, 5 were ectopic in the neck, and 10 were in the forearm. The ectopic parathyroid glands were located inside the thyroid gland (n=1), anterior superior mediastinum (n=1), or thymus (n=3). Surgical treatment significantly improved clinical symptoms such as skin pruritus and bone pain. Blood iPTH, Ca, P, ALP, and Ca*P were significantly reduced (P<0.05 or P<0.01) after surgery. Hypothyroidism occurred in 1 patient; 4 patients undergoing orthotopic neck surgery developed transient hoarseness, which were alleviated within 6 months; no severe complications such as bleeding or death were noted. No recurrence occurred during the 6-month follow-up.

Conclusions

Reoperation is safe and effective for drug-refractory SHPT. Preoperative imaging should be performed to achieve accurate positioning, and the recurrent laryngeal nerve should be closely monitored during surgery. The purpose of the reoperation is to remove all possible parathyroid tissues to avoid recurrence.

Shear Wave Elastography in Diagnosing Secondary Hyperparathyroidism

This study evaluates the diagnostic value of two-dimensional shear wave elastography (2 D-SWE) technique in the evaluation of hyperplastic parathyroid glands in cases with secondary and tertiary hyperparathyroidism. A total of 59 patients (end-stage renal disease, under supplemental dialysis program) with visible parathyroid hyperplastic glands on ultrasound, confirmed by biochemical assay and scintigraphy, were enrolled; they were examined on grayscale ultrasound and 2 D shear wave elastography. We determined the elasticity index (EI) in the parathyroid gland, thyroid parenchyma and surrounding muscles, and the elasticity ratio of hyperplastic parathyroid glands compared to muscle, specifically sternocleidomastoid muscle. Patients presented fibrocystic bone disease with secondary hyperparathyroidism induced by end-stage chronic kidney disease; being on prolonged chronic dialysis therapy, they had positive sestamibi scintigraphy and high values of serum parathormone (1141.04 pg/mL). Nodules placed posterior to the thyroid capsule that were cystic, had a hypoechoic aspect, and were homogenous with an independent afferent artery were found. Mean EI in the parathyroid gland was 7.83 kPa, the median value in thyroid parenchyma was 13.76 kPa, and mean muscle EI value was 15.78 kPa. The observed mean parathyroid/muscle SWE ratio was 0.5356 and the value for parathyroid/normal thyroid parenchyma was 0.5995. Using receiver operating characteristic (ROC) analysis, we found that EI below 9.74 kPa correctly identifies parathyroid tissue, with a sensitivity of 94.8%, specificity of 90.7%, and accuracy of 92.26% when compared to normal thyroid tissue. Compared with the muscle tissue, we identified that EI below 9.98 kPa has a sensitivity, specificity, and accuracy of 93.8%, 90.7%, and 91.75%, respectively. Ultrasound elastography is a helpful tool in identifying parathyroid hyperplasia in patients with chronic kidney disease. A cutoff value of 9.98 kPa can be used in 2 D-SWE for accurate diagnosis of parathyroid disease.

Long-term outcomes and management considerations after parathyroidectomy in the dialysis patient

Parathyroidectomy (PTX) remains an important intervention for dialysis patients with poorly controlled secondary hyperparathyroidism (SHPT), though there are only retrospective and observational data that show a mortality benefit to this procedure. Potential consequences that we seek to avoid after PTX include persistent or recurrent hyperparathyroidism, and parathyroid insufficiency. There is considerable subjectivity in defining and diagnosing these conditions, given that we poorly understand the optimal PTH targets (particularly post PTX) needed to maintain bone and vascular health. While lowering PTH after PTX decreases bone turnover, long-term changes in bone activity have been poorly explored. High turnover bone disease, usually present at the time a PTX is considered, often swings to a state of low turnover in the setting of sufficiently low PTH levels. It remains unclear if all low bone turnover equate with disease. However, such changes in bone turnover appear to predispose to vascular calcification, with positive calcium balance after PTX being a potential contributor. We know little of how the post-PTX state resets calcium balance, how calcium and VDRA requirements change or what kind of adjustments are needed to avoid calcium loading. The current consensus cautions against excessive reduction of PTH although there is insufficient evidence-based guidance regarding the management of chronic kidney disease - mineral bone disease (CKD-MBD) parameters in the post-PTX state. This article aims to compile existing research, provide an overview of current practice with regard to PTX and post-PTX chronic management. It highlights gaps and controversies and aims to re-orient the focus to clinically relevant contemporary priorities in CKD-MBD management after PTX.

Refractory hypercalcemia due to an ectopic mediastinal parathyroid gland in a hemodialysis patient: a case report

BACKGROUND

Hypercalcemia crisis is a complex disorder rarely induced by tertiary hyperparathyroidism, which clinically presents as nonsuppressible parathyroid hyperplasia with persistent increased PTH levels and hypercalcemia. It is one of the major risk factors of morbidity and mortality in end-stage renal disease. Parathyroidectomy should be in consideration in dialysis patients with severe hyperparathyroidism who are refractory to medical therapy. The implications and consequences of it, however, are not fully understood.

CASE PRESENTATION

We present a case of a 70 year-old man disturbed by gastrointestinal manifestations due to hypercalcaemic crisis. The patient had longstanding hypercalcaemia and hyperparathyrodism refractory to calcimimetics, calcitonin, hormone and haemodialysis. A ectopic parathyroid gland in anterior mediastinum was found and elucidated by Tc-99 m scan. Futhermore, a video-assisted thoracoscopic parathyroidectomy was performed. Histologically, the tumour consisted of densely arranged chief cells immunohistochemically positive for PTH antigens. Consequently, calcium and parathormone were declining stably without any complications.

CONCLUSIONS

On account of refractory hypercalcemia and hyperparathyroidism, radionuclide scanning is useful in the diagnosis of ectopic parathyroid gland. it is of great significance for multidisciplinary therapy combing anesthesia, surgical, endocrinology and nephrology staff.

Subtotal Parathyroidectomy vs Total Parathyroidectomy with Autotransplantation for Secondary Hyperparathyroidism in Dialysis Patients: Short- and Long-Term Outcomes

BACKGROUND

Two operations are performed for management of secondary hyperparathyroidism, subtotal parathyroidectomy (SPTX) and total parathyroidectomy with autotransplantation (TPTX-AT). There is no consensus among endocrine surgeons about which operation is the preferred treatment. This study compares the short- and long-term outcomes of SPTX and TPTX-AT for dialysis patients with secondary hyperparathyroidism.

STUDY DESIGN

This is a retrospective review of 46 dialysis patients undergoing PTX from 2006 to 2017 at a 719-bed tertiary care hospital.

RESULTS

Calcium on postoperative day 1 was 7.7 ± 0.8 mg/dL for SPTX and 7.9 ± 1.3 mg/dL for TPTX-AT (p = 0.49). Parathyroid hormone values on postoperative day 1 were 32.6 ± 26.0 pg/mL for SPTX and 9.5 ± 4.2 pg/mL for TPTX-AT (p ≤ 0.05). Hospital length of stay was 3.7 ± 1.9 days for SPTX and 4.4 ± 3.5 days for TPTX-AT (p = 0.46). The required doses of calcium and calcitriol at discharge did not differ significantly. Reoperation for recurrence or persistence of disease was required in 6 SPTX patients and 2 TPTX-AT patients (p = 0.12). Parathyroid hormone values <15 pg/mL at long-term follow-up occurred in 5.6% of SPTX patients and 26.7% of TPTX-AT patients (p = 0.09). Parathyroid hormone values >200 pg/mL at long-term follow-up occurred in 38.9% of SPTX patients vs 6.7% of the TPTX-AT patients (p ≤ 0.05). Calcium supplementation at more than 6 months was required for 36.8% of SPTX and 71.4% of TPTX-AT patients (p < 0.05).

CONCLUSIONS

The long-term control of parathyroid hormone elevation and avoidance of recurrent disease is improved with TPTX-AT, but carries a higher risk of long-term hypocalcemia.

Near total parathyroidectomy for the treatment of renal hyperparathyroidism

Background

Different surgical strategies are used to treat medical refractory renal hyperparathyroidism. Our preferred choice in patients with moderate secondary hyperparathyroidism (SHPT) and in patients with low compliance with medical treatment is to leave a very small parathyroid remnant in situ: we name this operation "near total parathyroidectomy" (ntPTX). We report here our results with this technique.

Methods

Retrospective study [2001-2015] of all patients submitted to ntPTX in a single centre.

Results

Forty-seven patients were submitted to ntPTX (32 males) aged 47.3 years. Follow-up time is 8.5 years. Thirty-five patients (74%) are alive, 12 are dead. One patient in this series had a functioning renal transplant at time of ntPTX (tertiary hyperparathyroidism), and other 27 subsequently received a renal transplantation (RTx) after ntPTX (still functioning at last follow-up or at death in 19). Amongst the 35 current survivors, the renal graft is functioning in 16 (45.7%). Parathyroid hormone (PTH) at follow-up was 116.1±135.5 pg/mL and calcium 8.6±0.9 mg/dL. Among patients with a functioning RTx PTH was 83 pg/mL and calcium 8.7 mg/dL. There was no persistent disease, and 3 patients (6.4%) had a relapse of hyperparathyroidism at follow-up.

Conclusions

ntPTX is associated to very satisfying rates of normal parathyroid function and of relapse of hyperparathyroidism (6.4%) at long term, either in case of RTx or of maintenance hemodialysis: the concept of "small amount" remnant represents a valuable choice for patients undergoing PTX with a realistic chance of receiving a RTx.

Impact of Different Levels of iPTH on All-Cause Mortality in Dialysis Patients with Secondary Hyperparathyroidism after Parathyroidectomy

Background

Secondary hyperparathyroidism (SHPT) usually required parathyroidectomy (PTX) when drugs treatment is invalid. Analysis was done on the impact of different intact parathyroid hormone (iPTH) after the PTX on all-cause mortality.

Methods

An open, retrospective, multicenter cohort design was conducted. The sample included 525 dialysis patients with SHPT who had undergone PTX.

Results

404 patients conformed to the standard, with 36 (8.91%) deaths during the 11 years of follow-up. One week postoperatively, different levels of serum iPTH were divided into four groups: A: ≤20 pg/mL; B: 21–150 pg/mL; C: 151–600 pg/mL; and D: >600 pg/mL. All-cause mortality in groups with different iPTH levels appeared as follows: A (8.29%), B (3.54%), C (10.91%), and D (29.03%). The all-cause mortality of B was the lowest, with D the highest. We used group A as reference (hazard ratio (HR) = 1) compared with the other groups, and HRs on groups B, C, and D appeared as 0.57, 1.43, and 3.45, respectively.

Conclusion

The all-cause mortality was associated with different levels of iPTH after the PTX. We found that iPTH > 600 pg/mL appeared as a factor which increased the risk of all-cause mortality. When iPTH levels were positively and effectively reducing, the risk of all-cause mortality also decreased. The most appropriate level of postoperative iPTH seemed to be 21–150 pg/mL.