Results of ultrasonically guided percutaneous ethanol injection into parathyroid adenomas in primary hyperparathyroidism

Case report: Laryngospasm following ethanol ablation of a parathyroid nodule in a dog with primary hyperparathyroidism

A 12-year-old female spayed dachshund was presented for emergency assessment of respiratory distress, characterized by inspiratory dyspnea with stridor. Percutaneous ultrasound-guided ethanol ablation of a functional parathyroid tumor was performed 72-h earlier for management of primary hyperparathyroidism. The dog was hypocalcemic (ionized calcium 0.7 mmol/L, reference interval: 0.9-1.3 mmol/L) at the time of presentation and had evidence of laryngospasm on a sedated oral exam. The dog was managed conservatively with supplemental oxygen, anxiolysis, and parenteral calcium administration. These interventions were associated with rapid and sustained improvement in clinical signs. The dog did not demonstrate any recurrence of signs afterwards. To the authors' knowledge, this is the first description of laryngospasm following ethanol ablation of a parathyroid nodule in a dog that developed hypocalcemia.

Percutaneous ethanol injection therapy: a surgery-sparing treatment for primary hyperparathyroidism

OBJECTIVE

To describe our 3-year experience in the long-term efficacy and safety of percutaneous ethanol injection therapy (PEIT), as an alternative to surgery for the management of patients with primary hyperparathyroidism (p-HPT).

DESIGN

Prospective study with a mean follow-up of 19.6 +/- 10.6 months.

PATIENTS

Our study population included 19 consecutive high risk patients with p-HPT, who met the criteria for surgery.

MEASUREMENTS

Under ultrasonic guidance, ethanol (95%) was injected into parathyroid glands with a volume of >or= 0.15 cm(3). With the aim of normalizing intact parathormone (iPTH) values, repeated ethanol injections were carried out, in an interval of 2 weeks, until normalization of iPTH was reached or until no residual blood supply was detected by ultrasound in the gland. Biochemical parameters were monitored throughout the study.

RESULTS

At 6-month follow-up, normalization of iPTH levels (10-65 ng/l) was achieved in 11 (58%) patients (responders). Of the eight remaining patients (nonresponders), six patients had reduced (but not normalized) iPTH levels and two patients required parathyroid surgery. Seventeen (11 responders and 6 nonresponders) of the 19 patients (89.5%) became normocalcaemic (serum Ca <or= 2.57 mmol/l) and remained so for a mean follow-up of 21 months (8-39 months). The odds ratio (P < 0.05) of response vs. no response to PEIT was 16.7-fold for pretreatment iPTH < 200 vs. > 200 ng/l. The only complication was a transient dysphonia noticed in three patients.

CONCLUSIONS

PEIT is a safe and effective nonsurgical treatment for patients with p-HPT, who are unsuitable for surgical intervention.

Modified percutaneous ethanol injection of parathyroid adenoma in primary hyperparathyroidism

Surgery is the treatment of choice for symptomatic primary hyperparathyroidism; unlikely few patients do not meet established surgical criteria or have comorbid conditions that prohibit surgery. In these subjects, medical therapy alone offers little hope for a sustained long normocalcemic period. However percutaneous ethanol injection (PEI) may represent an alternative therapeutic procedure. It is currently in use for the treatment of secondary or tertiary hyperparathyroidism, however, few studies or case reports suggest it for the treatment of primary hyperparathyroidism. Moreover, little information is available about the long-term follow-up, where incomplete necrosis or the spreading of ethanol in the surrounding tissues is often reported. We believe that many of the side effects could be correlated to procedure itself. Taking these experiences into account, we have reasoned that in order to limit these side effects, we had to modify the standard PEI procedure. We reported this preliminary experience describing our modified PEI procedure.

Parathyroid sonography: imaging and intervention

This article reviews the role of high-resolution sonography as an imaging modality for the diagnosis and treatment of patients with parathyroid disease. Included is a discussion of sonographic anatomy and technique, disease processes of the parathyroid glands and their sonographic appearances, preoperative imaging, and the use of sonography as a guide for diagnostic and therapeutic intervention in parathyroid disease.

Percutaneous ultrasound-guided radiofrequency heat ablation for treatment of hyperthyroidism in cats

OBJECTIVE

To determine efficacy and safety of percutaneous radiofrequency heat ablation for treatment of hyperthyroidism in cats.

DESIGN

Prospective study.

ANIMALS

9 cats.

PROCEDURE

Hyperthyroidism was diagnosed via clinical signs and high serum total (TT4) and free thyroxine (fT4) concentrations. One or 2 hyperfunctional cervical thyroid nodules were detected by use of scintigraphy and ultrasonography. If cats had 1 abnormal thyroid lobe, heat ablation was performed on that lobe; if cats had 2 abnormal lobes, heat ablation was applied to the larger lobe. Overall, heat ablation was performed 14 times in the 9 cats. Clinical signs and serum TT4, fT4, and calcium concentrations were monitored daily for 2 days after the procedure, weekly for the first month, and then monthly. Laryngeal function was evaluated and cervical ultrasonography and thyroid scintigraphy were also performed. Monitoring continued for as long as 9 months after heat ablation if a cat became euthyroid or until an owner chose an alternative treatment because of recurrence of hyperthyroidism.

RESULTS

Serum TT4 and fT4 concentrations transiently decreased after all 14 heat ablation procedures (< or = reference range after 10 of 14 treatments) within 2 days after the procedure. Cats were euthyroid for 0 to 18 months (mean, 4 months). Hyperthyroidism recurred in all cats. Adverse effects included transient Horner's syndrome (2 cats) and laryngeal paralysis without clinical signs (1 cat).

CONCLUSIONS AND CLINICAL RELEVANCE

Percutaneous heat ablation as a treatment for hyperthyroidism in cats is effective transiently but not permanently.

Tissue Chemoablation

PURPOSE

To provide an overview of the state of the art of tissue chemoablation in animal and human organs and cancers. We also describe our experience with the feasibility, predictability, and reproducibility of necrosis produced by needle chemoablative therapies including ethanol, hypertonic saline, and acetic acid solutions as well as gels in a porcine renal model.

MATERIALS AND METHODS

A MEDLINE search was performed for articles on animal and human tissue chemoablation published since 1965. In addition, at Washington University, experimental chemoablation was performed in pigs with 95% ethanol (4 mL), 24% hypertonic saline (4 mL), or 50% acetic acid (4 mL) solutions as well as in gel form.

RESULTS

There is extensive literature on the use of chemoablation for liver metastases; recently, chemoablation of the prostate has become an area of research. Human studies have been limited to patients who are not surgical candidates or to investigational procedures performed prior to definitive prostatic surgery. Animal studies of renal chemoablation as a sole therapy have produced mixed results. In our studies, only acetic acid provided complete necrosis.

CONCLUSIONS

To date, ethanol chemoablation has been shown to be feasible and reproducible only for metastatic hepatic carcinoma. In urology, chemoablation is still very much in the investigational stage for both the prostate and the kidney. A significant drawback is that even in the gel form, the spread of the chemoablative substance through the tissue is irregular and unpredictable. In the future, chemoablation may become a more effective modality by combining it with radiofrequency or other energy sources.

[Parathyroid cyst. Report of ten cases]

AIM OF THE STUDY

To evaluate the characteristics of the parathyroid cysts (PC).

PATIENTS AND METHOD

Ten patients with PC were included in this retrospective study. The PC were discovered as follows: cervical mass (n = 3), hyperparathyroidism (n = 3), incidentally during thyroid surgery (n = 3) and screening for obesity (n = 1). Intracystic parathormone determination was performed after fine needle aspiration in 2 cases.

RESULTS

Mean cyst measurements were 27 mm (ext: 5-70 mm) to 22 mm (5-45 mm). Nine cysts were cervical (resection by cervicotomy), and one was mediastinal (resection by sternotomy). In addition to the resection of the PC, 3 adenomas, 1 hyperplasia of the parathyroid glands and 3 benign thyroid diseases were recognized and treated during the cervicotomies.

CONCLUSION

The diagnosis of PC is not common and must be based primarily on the study of the cyst liquid obtained by percutaneous puncture (intracystic parathormone measurement).

Percutaneous ultrasonographically guided radiofrequency heat ablation for treatment of primary hyperparathyroidism in dogs

OBJECTIVE

To evaluate the efficacy and safety of ultrasonographically guided radiofrequency heat ablation of parathyroid masses in dogs with primary hyperparathyroidism.

DESIGN

Clinical trial.

ANIMALS

11 dogs.

PROCEDURE

In all dogs, either 1 or 2 parathyroid masses were evident ultrasonographically. Dogs were anesthetized, and a 20-gauge over-the-needle catheter was directed into the parathyroid mass via ultrasonographic guidance. Radiofrequency heat was applied to the stylet of the catheter until there was sonographically apparent change to the entire parenchyma of the mass. Serum total and ionized calcium and parathyroid hormone concentrations were monitored daily for 5 days after the ablation procedure and again at 1, 2, and 3-month intervals, if possible. Dogs were monitored for adverse effects.

RESULTS

One treatment was required in 6 dogs, 2 treatments were required in 2 dogs, and treatment was unsuccessful in 3 dogs. Serum total and ionized calcium concentrations were within reference ranges within 2 days of the last procedure in all 8 successfully treated dogs. Serum parathyroid hormone concentration was decreased 24 hours after treatment in all 8 dogs. Hypocalcemia developed in 5 of the 8 successfully treated dogs, all of which required treatment. One dog had a transient voice change. Other adverse effects were not reported.

CONCLUSIONS AND CLINICAL RELEVANCE

Ultrasonographically guided radiofrequency heat ablation of parathyroid masses is a safe and effective alternative to surgery in dogs with primary hyperparathyroidism.

[Treatment of parathyroid adenomas with ethanol injection under ultrasonographic guidance]

STUDY OBJECTIVE

The objective of this retrospective study was to report the results of ethanol injection in parathyroid adenomas.

PATIENTS AND METHOD

Since 1988, 31 patients with inoperable primary hyperthyroidism have been treated by ultrasound-guided percutaneous ethanol injection into the adenoma. The main surgical contraindications were heart failure (n = 12) and age over 85 years (n = 11). Plasma calcium and PTH were measured 48 hours after ethanol injection and during subsequent follow-up.

RESULTS

Patients had one to three ethanol injections. With a mean 5-year follow-up, total success with normal plasma calcium and PTH levels was achieved in 20 patients (64.5%), 4 of whom underwent another ethanol injection after 1 to 3 years. Partial success with correction of plasma calcium only was achieved in 9 patients (29%) resulting in an obvious clinical benefit. Failure was observed in 2 patients (6.5%) with nodular goiter, probably due to incorrect localization of the adenoma. Treatment was always well tolerated and no major side effect was observed.

CONCLUSION

Ultrasound-guided percutaneous ethanol injection of parathyroid adenoma is effective in most cases of hyperparathyroidism and very useful in patients with a high surgical risk. The need for precise ultrasound localization of the adenoma is the main limitation of this treatment.

Indications, technique, and efficacy of alcohol injection of enlarged parathyroid glands in patients with primary hyperparathyroidism

BACKGROUND

Percutaneous alcohol ablation of the parathyroid gland (PAAP) has been proposed as an alternative treatment for primary hyperparathyroidism in patients unsuitable for surgery. The current study aimed to determine the (1) selection criteria, (2) associated morbidity, and (3) efficacy of PAAP.

METHODS

From 1987 to 1998, 36 patients with primary hyperparathyroidism (mean age 65 years) underwent PAAP. The indications for PAAP were (1) medical comorbidity, (2) technically unsafe reoperative surgery, (3) partial ablation of a single remaining gland, and (4) patient choice.

RESULTS

There were no long-term complications. Two patients had temporary recurrent laryngeal nerve injury and 4 had temporary hypocalcemia. Over a median follow-up of 16 months, 12 (33%) of the patients remained eucalcemic. For analysis purposes patients were separated into 2 separate groups: 29 with attempted complete ablation and 7 with partial ablation of a single remaining gland only. Ten of the complete ablation group (34%) remained eucalcemic. In the partial ablation group only 2 remained eucalcemic, but all had adequately controlled serum calcium levels.

CONCLUSION

PAAP should be considered for hyperparathyroid patients with excessive reoperative morbidity or prohibitive medical comorbidity or those in whom the intent is to partially ablate a single remaining enlarged gland. In these patients close follow-up of serum calcium is required, and repeat treatments may be necessary because recurrence of hypercalcemia is likely.

Parathyroid carcinoma

BACKGROUND

Parathyroid carcinoma is rare and represents 0.1% to 5% of the cases of hyperparathyroidism. New accounts are important to the understanding of these tumors. Experience in 9 cases is reported.

METHODS

From 1970 to 1995, 10 patients with parathyroid carcinoma demonstrated by clinical course or pathologic features of malignancy were treated. The patient's clinical data, laboratory and imaging examinations, surgical findings, pathology, recurrences, and survival were analyzed.

RESULTS

One male patient was excluded because of insufficient data. Average age was 51 years, with female:male ratio of 2:1. Average calcium level was 14,3 mg/dL. Palpable mass was found in 55%, bone disease in 89%, and renal disease in 78%. Four patients were reoperations. Five were operated on for hyperparathyroidism (1/tertiary). Capsular invasion was the most incident pathologic feature. Local recurrence occurred in 55%; neck node and bone metastasis in 11%, and lung in 33%. Two patients are alive and 5 died of disease.

CONCLUSIONS

Parathyroid carcinoma has clinical and laboratory features that can help diagnosis at the first surgery. It seems to have variable malignancy.

Primary Hyperparathyroidism: Diagnosis and Management

OBJECTIVE

To review the manifestations of primary hyperparathyroidism and the available treatment strategies.

METHODS

The epidemiologic and pathologic features of this endocrine disorder are outlined. Guidelines for surgical intervention are discussed, and the effectiveness of various medical treatments is summarized.

RESULTS

Primary hyperparathyroidism, a common disorder, is diagnosed on the basis of hypercalcemia in the presence of increased parathyroid hormone levels as measured by immunoassay. Clinical manifestations are variable with many patients being asymptomatic at the time of diagnosis. Patients with severe disease require definitive surgical treatment. Surgical cure rates are high--approximately 95% in experienced hands. Indications for surgery include a serum calcium of more than 2.9 mmol/L (12 mg/dL), osteoporosis, recurrent renal stones, and parathyroid carcinoma. As well, it is recommend in individuals younger than 50 years of age. Patients with mild disease may have a benign natural history and may not have progression to severe disease. Asymptomatic individuals with mild hypercalcemia and close to normal bone mass and renal function may be managed medically, particularly those who are over the age of 50 years. Medical management includes ensuring adequate hydration and avoiding volume depletion. Estrogen therapy is valuable in postmenopausal women without contraindications to hormone replacement. Calcitonin has been shown to decrease serum calcium levels on a short-term basis. Bisphosphonates are also potential treatment options and require further study. Calcium-mimetic agents also may become valuable in the medical management of primary hyperparathyroidism in the near future.

CONCLUSION

As primary hyperparathyroidism is being increasingly detected at an asymptomatic stage, medical therapy is assuming a greater role in the effective management of this common condition.