Secondary hyperparathyroidism. The role of surgery

A retrospective analysis was undertaken to better define the clinical presentation and therapy of patients with secondary hyperparathyroidism and the timing of surgical removal of the parathyroid glands in secondary hyperparathyroidism. Sixty-eight patients with end-stage renal disease (ESRD) underwent 74 parathyroid procedures over a 10-year period. There were 38 per cent women and 62 per cent men in this population--the same proportion of men and women with ESRD. These proportions are reversed when compared with patients with primary hyperparathyroidism. The mean time between initiation of dialytic therapy and parathyroidectomy was 5.4 years. Preoperative mean serum calcium and phosphorus levels were 10.1 +/- 0.2 and 6.1 +/- 0.2 mg/dl, respectively. All patients were symptomatic and 60 per cent of the patients had at least two symptoms before surgery. Renal osteodystrophy was the most common symptom (74%), whereas pruritus was noted in 65 per cent of this population. Patients underwent either subtotal (88%) or total (12%) parathyroidectomy with autotransplantation. Six patients required reoperation: five for recurrent disease (2 to 5 years after the initial surgery) and one for persistent disease. All patients were symptomatically improved after the surgery. Complications included the following: transient hoarseness (7%), hypocalcemia requiring calcium, and/or vitamin D therapy (32%) for 6 months after surgery. This analysis demonstrates that although the initial therapy of secondary hyperparathyroidism is medical, surgical therapy should be instituted before multiple symptoms develop in the ESRD population.     

Primary massive reflux in children.

Over a ten-year period, of more than 1,000 children whose primary vesicoureteral reflux was treated surgically, there were 54 children with 80 single ureters which were massively dilated. Primary reconstruction with ureteral tailoring was done in 25 ureters with a success rate of 92 per cent. Forty-five ureters were temporarily diverted because of uncontrolled infection and/or azotemia. In almost half of these instances, temporary diversion resulted in improvement in ureteral caliber to such an extent that nontailored reimplantation could be performed with a success rate of 87 per cent. Six kidneys were removed and four have been maintained in the diverted state with severe renal dysplasia. Eighty-eight per cent of the refluxing megaureters were reconstructed with a success rate of 89 per cent.     

Clinical manifestations of primary hyperparathyroidism before and after parathyroidectomy. A case-control study.

BACKGROUND: There has been an National Institutes of Health consensus meeting concerning the management of patients with "asymptomatic" primary hyperparathyroidism, yet there is no clear definition of this condition. The authors, therefore, documented the clinical manifestations and frequencies of these manifestations in unselected patients with primary hyperparathyroidism and determined whether these clinical manifestations resolved after parathyroidectomy. METHOD: The authors studied 152 unselected consecutive patients with primary hyperparathyroidism and 132 control patients with nontoxic thyroid disorders who were treated by parathyroidectomy or thyroidectomy, respectively, between January 1986 and June 1991. All patients received a questionnaire during their initial office visits and the same questionnaire again after their operations. Patients were also questioned about their perception of the success of the operation. Eighty percent of the parathyroid patients and 70.5% of the thyroid patients completed the questionnaires, and the mean follow-up time was 20 months. RESULTS: Only 7 (4.6%) patients with primary hyperparathyroidism had no symptoms, and 26 (17.1%) had no associated conditions despite 74.3% of these patients having serum calcium levels less than 12 mg/dL. Symptoms including fatigue, exhaustion, weakness, polydipsia, polyuria, nocturia, joint pain, bone pain, constipation, depression, anorexia, nausea, heartburn, and associated conditions, including nephrolithiasis, and hematuria occurred more often in patients with primary hyperparathyroidism than in the thyroid control patients (p < 0.05). After parathyroidectomy, only eight (5.3%) patients failed to have any improvement in symptoms or associated conditions. Fifty-seven percent of the parathyroid patients versus 30% of the thyroid patients felt better overall after the operation, strength subjectively improved in 29% of parathyroid patients versus 13% in thyroid patients; thirty-seven percent of the parathyroid patients versus 13% of the thyroid patients claimed they were less depressed. CONCLUSION: When examined thoroughly, few patients with primary hyperparathyroidism were asymptomatic or without associated conditions, and most patients experienced subjective improvement after successful parathyroidectomy.     

Some characteristics of recurrent calcium stone formers in Puerto Rico.

We have studied 83 patients with recurrent calcium stone formation in an attempt to determine an approximate incidence of metabolic disturbances associated with stone disease. Male veterans (n = 42), male non-veterans (n = 13), and women (n = 28) composed the group. We divided the groups in such fashion because they represented generally two distinct socioeconomic groups. Primary hyperparathyroidism was present in 19 per cent of the subjects; a marked predominance of women (15/16) was noted. Hypercalciuria of renal or intestinal origin was present in 23 per cent of the group. Of interest was a group of male veterans (17/83) in whom normocalciuria, normocalcemia, and normal serum phosphate were associated with high values of immunoreactive parathyroid hormone. These subjects had low urine phosphate. This set of findings indicates that these patients may be a new subgroup of stone-forming patients. Metabolic abnormalities could not be detected in 38 per cent of the patients. Classification of stone subjects is essential for rational management.     

Primary juvenile hyperparathyroidism. Report of 24 cases

AIM OF THE STUDY: Primary hyperparathyroidism usually affects elderly patients. Juvenile primary hyperparathyroidism is rare, and raises diagnostic and prognostic problems. The aim of this retrospective study on 24 patients is to establish clinical, histological, and therapeutic features of juvenile primary hyperparathyroidism. PATIENTS AND METHODS: From 1986 to 2001, 673 patients were treated for primary hyperparathyroidism in our department. Twenty four patients were younger than 30 years old (3.5%). There were 14 women and 10 men. Mean age was 23 year (14-30). Clinical manifestations, pathologics findings and postoperative results were studied. RESULTS: Sixteen patients presented a sporadic form of primary hyperparathyroidism with a single adenoma. Clinical manifestations were renal symptoms in 11 cases and acute hypercalcemia syndrome in 2 cases. Seven patients had a NEM I syndrome: parathyroid lesions were 6 hyperplasia and one adenoma. A 27 years old woman presented a recurrent familial isolated hyperparathyroidism. She was operated on 10 years before and at reoperation parathyroid carcinoma was found. Nineteen patients were cured after a post operative follow up ranging from 3 to 168 months. One patient had an asymptomatic hypercalcemia recurrence. Two patients presented permanent hypoparathyroidism treated with calcitriol and calcium. CONCLUSION: Sporadic forms represent majority of cases of juvenile hyperparathyroidism. Renal manifestations are usual. Nevertheless, multiple endocrine neoplasia type 1 has to be evocated.     

Hyperparathyroidism in thyrotoxicosis

The frequency of hypercalcemia in 295 patients treated for thyrotoxicosis was 2 per cent. The combination of thyrotoxicosis and hyperparathyroidism is rare and only twenty-seven well documented cases could be found in the literature. Among ninety-two patients operated on for hyperparathyroidism, ten of them had thyrotoxicosis. In the present study, data on thirty-seven patients are reported. Hypercalcemia was found in all the patients and four of them had acute hyperparathyroidism. Hypophosphatemia was recorded in 60 per cent and hypercalcuria in 75 per cent of the patients. In ten patients there were renal concretions. Skeletal roentgenograms showed abnormalities in 65 per cent of the patients.     

Management of perianal sepsis in immunosuppressed patients

Despite improvements in the supportive care of immunosuppressed patients controversy still surrounds the surgical management and outcome of anorectal sepsis in these patients. We reviewed 83 immunocompromised patients with diagnosis of perianal sepsis from 1995 to 1997. Sixty-six patients (80%) were followed for a mean of 15 months. Mean age was 44 years and 76 per cent were males. Twenty-eight per cent were HIV+, 34 per cent had inflammatory bowel disease on steroids, 20 per cent had malignancies, and 18 per cent had diabetes. Twenty-eight per cent had anal fistula, 2 per cent had perianal abscess, and 40 per cent had both. Primary sites of fistula were: transsphincteric (38%), intersphincteric (33%), superficial (20%), and suprasphincteric (3%), and multiple tracks (6%). Horseshoeing was present in 14 per cent of cases. The most commonly practiced surgical procedures were primary fistulotomy (n = 23) and fistulotomy plus drainage (n = 28). Seven patients underwent fistulotomy and ostomy and eight patients were treated with fistulectomy plus drainage. Most wounds (91%) healed within 8 weeks. Incontinence (6%) and recurrence (7%) were the most commonly observed complications. These results are similar to those seen in the general population. Perianal sepsis can be safely managed in immunocompromised patients, with high rates of healing and low complication rates. An aggressive sphincter-preserving approach in the management of these patients may be undertaken.     

Primary versus staged resection for acute obstructing colorectal carcinoma.

The management of 115 patients with complete neoplastic obstruction of the colon was studied retrospectively. Primary resection was carried out in 40 patients, 22 with right-sided and 18 with left-sided tumours. Staged resection was planned in 48 patients and actually performed in 40. Creation of a stoma only was carried out in 25 patients because of advanced disease. There were no differences between primary and staged resection regarding the patients' general condition, concurrent disease, tumour stage according to Dukes' classification, postoperative complications, or mortality. The postoperative mortality rate was 10 per cent after primary and 15 per cent after staged resection (P not significant). The median hospital stay was 18 and 45 days, respectively. The 5-year survival rate was 38 per cent after primary and 29 per cent after staged resection. All primary resections but one were performed by qualified surgeons, while trainees created stomas as emergency treatment. The similarity in outcome suggests that in future this condition should, where possible, be treated by primary resection, by surgeons experienced in colorectal operations.     

Thallium isotope scintigraphy and ultrasonography: comparative studies of localization techniques in primary hyperparathyroidism

Controversy exists about whether preoperative localization procedures are indicated in patients with primary hyperparathyroidism before first neck exploration. Currently, thallium subtraction scintigraphy and ultrasonography are the techniques used most frequently. This paper examines prospectively the accuracy and value of these techniques in a group of 71 patients with primary hyperparathyroidism. When considering all glands, thallium scanning produced a sensitivity of 46.6 per cent with a specificity of 91.5 per cent, compared with a sensitivity of only 21.4 per cent and specificity of 94.5 per cent for ultrasonography. Accuracy rates, for all glands, were 80 per cent and 75.7 per cent respectively. Both localization procedures were consistently ineffective in localizing adenomas weighing less than 500 mg, over 80 per cent of which went undetected by both scanning modalities. While both scans produced satisfactory results in localizing adenomas weighing more than 1 g, these adenomas should not represent a challenge to an experienced endocrine surgeon and, therefore, neither localization is recommended before first neck exploration.     

The utility of a rapid parathyroid assay for uniglandular, multiglandular, and recurrent parathyroid disease

The rapid parathyroid hormone assay (rPTH) is an effective tool in minimally invasive resections of parathyroid adenomas. However, there are relatively few reports examining its utility in the full spectrum of parathyroid disease. The purpose of this study was to examine the utility of the rapid parathyroid hormone assay in uniglandular, multiglandular, and recurrent hyperparathyroidism. A retrospective analysis of all patients undergoing parathyroid resection from June 2001 to March 2003 was undertaken. All patients underwent preoperative localization studies. Rapid parathyroid hormone (PTH) levels were drawn immediately prior to and 10 minutes following parathyroid resection. A decline of > or = 50 per cent rPTH qualified as a successful/complete resection. Additional intraoperative samples were drawn as needed for patients with multiglandular disease. Of 46 treated patients who were examined (average age, 54 years), 30 had single, 12 patients had multigland disease, and 4 had recurrent/persistent hyperparathyroidism. Thirty-seven patients had primary hyperparathyroidism (32 with single and 3 with double adenomas; 2 with hyperplasia), 4 patients had secondary hyperparathyroidism, and 5 tertiary hyperparathyroidism. All procedures were considered successful, as every patient exhibited a postresection decrement in rPTH exceeding 50 per cent (average decrement, 91%). Although 2 patients exhibited a postoperative PTH increase exceeding 50 per cent of the preoperative value, all remained asymptomatic and eucalcemic (median follow-up, 21.5 months). The rPTH assay is an effective tool in determining success of parathyroidectomy in patients with primary uni- and multiglandular as well as recurrent hyperparathyroidism. It can be used to achieve minimally invasive neck dissections or guide surgical decision-making in more complex cases.     

Primary venorrhaphy for traumatic inferior vena cava injuries

Primary venorrhaphy for traumatic inferior vena cava (IVC) injury has been criticized because of the potential for stenosis, thrombosis, and embolism. A retrospective study was performed to evaluate the morbidity and outcome of this method. Thirty-eight patients at our institution had traumatic injuries to the IVC between 1994 and 1999. Thirty (79%) were from firearms, five (13%) from stab wounds, and three (8%) from blunt trauma. Six patients died in the emergency department. The remaining 32 patients underwent exploratory celiotomy with 23 survivors and nine intraoperative deaths for a mortality rate of 28 per cent (nine of 32). Vascular control was achieved by manual compression in 44 per cent and by local clamping directly above and below the injury in 38 per cent. All repairs were by primary venorrhaphy, and no patient was treated with patch angioplasty or venous reconstruction. Three patients had caval ligation. Follow-up IVC imaging in 11 patients revealed that the IVC was patent in eight, narrowed in two, and thrombosed below the renal veins in one. One patient developed a pulmonary embolus. The vast majority of traumatic injuries to the IVC can be managed by direct compression or local clamping and primary venorrhaphy. Direct repairs are associated with a low thrombosis and embolic complication rate.     

The role of routine biopsy of all parathyroid glands in primary hyperparathyroidism

Since 1974, a concerted effort has been made to identify and biopsy all parathyroid glands in patients presenting with primary hyperparathyroidism. From 1974 until July 1982, 247 patients had initial cervical exploration for primary hyperparathyroidism. The percentage of patients in whom four or more glands were identified rose from 53 per cent in 1974 to as high as 88 per cent, with a mean of 80 per cent during the 8.5-year period. Ectopic location, prior thyroid surgery, and detrimental effects of prolonging surgery in some patients are reasons precluding localization of all glands in every patient. The percentage of biopsies positive for parathyroid tissue rose from 78 per cent in 1974 to 94 per cent in 1982. Routine biopsy of all glands provided the following results of classification in the 247 cases: adenoma, 56 per cent; diffuse hyperplasia, 18 per cent; nodular hyperplasia, 24 per cent; carcinoma, 0.8 per cent; and in three cases, four normal glands were identified. The one major complication was a case of temporary bilateral recurrent laryngeal nerve palsy. Mean follow-up period is 3 years. There was no case of permanent hypocalcemia and no operative deaths. Persistence and recurrence rates are 4.9 per cent and 0.4 per cent, respectively. Four of the patients with persistence and the one patient with recurrence have required reexploration. All but one of these was considered cured by reoperation. Eight of the 12 patients with initial persistent hypercalcemia postoperatively have been managed conservatively. These results suggest routine attempts to identify and biopsy all glands can be performed with minimal risk and complications and without permanent hypocalcemia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Operative management of severe constipation

This report investigates the concept that severe constipation requiring major abdominal surgery may result from one of three common causes: 1) colonic inertia, 2) pelvic hiatal hernia, or 3) both colonic inertia and pelvic hernia. This study evaluates the symptoms, anatomy and outcome in 201 patients with severe surgical constipation treated by a single surgeon. In 2042 patients with constipation referred to one colon and rectal surgeon, 211 major abdominal surgical procedures were performed on 201 patients for severe constipation between 1989 and 1999. There were 187 women and 14 men. Mean age was 49 years (range, 9-84). Five high-risk patients had ileostomy; 196 had major colonic surgery for anatomic or physiologic causes of constipation, excluding malignancy, diverticular disease, and inflammatory bowel disease. Pelvic hiatal hernia was defined as the herniation of bowel through the hiatus of the pelvic diaphragm seen on pelvic videofluoroscopy or physical examination. Of these 196 patients, 44 per cent had pelvic hiatal hernia repair (PHHR), 27 per cent had total abdominal colectomy and ileorectal anastomosis for colonic inertia, and 29 per cent had surgery for both colonic inertia and pelvic hiatal hernia. Of the 144 patients undergoing PHHR, 95 had Gore-Tex patch (W. L. Gore and Associates, Inc., Phoenix, AZ) sacral colpopexy. PHHR for pelvic hiatal hernia without colonic inertia included sigmoid resection, rectopexy, and Gore-Tex patch sacral colpopexy. Mean duration of follow-up was 20 months. Symptoms noted preoperatively included abdominal pain (84%), straining at stool (90%), incomplete rectal emptying (85%), painful bowel movements (74%), pelvic pain (69%), vaginal bulge (55%), digital assistance with evacuation (35%), and incontinence of stool (38%). Outcome assessed by symptom relief was successful in 89.1 per cent of patients. 8.6 per cent of patient conditions were unchanged, and 2.3 per cent were unsatisfied with the outcome. There were no postoperative deaths. The complication rate was 6.1 per cent (small bowel obstruction, 7; anastomotic leak, 2; ureteral stenosis, 2; and patch erosion, 1). In our experience, severe surgical constipation can be due to colonic inertia, pelvic hiatal hernia, or both. Careful preoperative evaluation identifies these disorders, and surgical therapy aimed at correction of anatomic and physiologic defects results in high patient satisfaction and improvement in bowel function.     

Primary hyperparathyroidism. Pathogenesis--diagnosis--therapy]

A report is given on 33 patients with primary hyperparathyroidism who underwent surgical treatment in our institution in the period from 1980 to 1989. In 57 per cent of the cases a hypercalcaemic syndrome was present. The primary hyperparathyroidism manifested itself in 75 per cent at the kidneys in the form of nephrolithiasis. One third of the patients showed a renal manifestation form exclusively. Remarkable is the relatively high number of exclusively gastrointestinal manifestations (11 per cent). In all patients the diagnosis was established on the coincidence of hypercalcaemia and increased parathormone in the serum. Preoperative localization diagnostics by means of parathyroid sonography, computed tomography and scintigraphy yielded unsatisfactory results. A satisfactory accuracy with regard to the lateral localization of the hyperfunctioning parathyroid tissue can presently be achieved only by selective catheterization of the cervical vein with determination of the parathormone. 35 patients clinically suspected of having primary hyperparathyroidism were subjected to a total of 44 operative interventions, i.e., apart from 35 primary operations, 7 secondary and 2 tertiary interventions. Of the 35 primary operations, 10 (28.6 per cent) were without success. This was due to 2 misdiagnoses and 8 cases with insufficient intraoperative exploration and premature discontinuation of the operation. In 67 per cent of the cases, there was a predominance of the solitary parathyroid adenoma, which was chiefly located at the dorsal lower thyroid poles. In order to reduce the number of unsuccessful primary interventions, a surgically-tactical approach is recommended.     

Short-term results of femoropopliteal subintimal angioplasty

BACKGROUND: Subintimal angioplasty may be more successful than conventional (intraluminal) angioplasty for treatment of long femoropopliteal occlusions. This study assessed the clinical and haemodynamic outcome of subintimal angioplasty. METHODS: All patients with femoropopliteal occlusions treated by subintimal angioplasty over a 3-year period at two centres were reviewed. Clinical assessment and colour duplex imaging were carried out. RESULTS: Sixty-nine procedures were performed in 33 men and 33 women of median age 74 (range 47-92) years. Indications for treatment were intermittent claudication in 26 (38 per cent) and critical limb ischaemia in 43 (62 per cent). Median occlusion length was 10 (range 2-50) cm. Primary technical success was achieved in 51 occlusions (74 per cent). There were 11 complications (16 per cent); the majority were minor but surgical intervention was required in two patients (3 per cent). At 6 months the cumulative symptomatic and haemodynamic primary patency rates were 60 and 51 per cent respectively, analysed on an intention-to-treat basis. The symptomatic and haemodynamic patency rates for technically successful procedures were 80 and 77 per cent respectively. CONCLUSION: In this series the short-term clinical success of subintimal angioplasty was poor because of a high incidence of reocclusion and restenosis, despite a relatively high initial technical success rate.     

Pancreatitis and hyperparathyroidism

Hypercalcaemia is considered to be a rare cause of pancreatitis but the true cause-and-effect relationship between hyperparathyroidism and pancreatic inflammatory disease remains controversial. Over 100 patients have been reported in whom both processes have occurred concurrently, but doubts have been expressed as to whether or not this association is due to chance. We report 10 new cases of hypercalcaemic hyperparathyroidism associated with different types of pancreatitis. Seven patients had primary hyperparathyroidism and three had hyperparathyroidism after renal transplantation. Two experienced acute pancreatitis after parathyroidectomy. Of the remaining eight patients, five had hypercalcaemia equal to or above 120 mg/l. The prevalence of pancreatitis in our series of 86 cases of primary hyperparathyroidism is 8 per cent. Acute and chronic calcifying types of pancreatitis were observed. Three patients died of the disease, two of them after renal transplantation. It is suggested that pancreatitis may complicate the clinical course of hyperparathyroidism, particularly when hypercalcaemia is moderate to severe and/or there are other risk factors such as treatment with steroids and azathioprine after renal transplantation.     

Barrett's oesophagus: effect of antireflux surgery on symptom control and development of complications.

Forty-five patients with histologically proven Barrett's columnar-lined oesophagus (CLO) were treated in one unit over a 9-year period. Patients were studied prospectively as part of a surveillance programme; all initially received standard conservative treatment including high-dose H2-receptor antagonists. A satisfactory initial response was seen in 21 patients, but in 24 the symptoms were unchanged or progressed; 19 patients in the latter group were considered suitable for antireflux surgery and underwent fundoplication. Symptoms of heartburn or dysphagia persisted or recurred in 88 per cent of patients receiving medical treatment alone and complications developed in 38 per cent, including nine strictures and one adenocarcinoma. In patients undergoing antireflux surgery, symptoms persisted or recurred in 21 per cent and complications developed in 16 per cent (P < 0.01). Complete regression of Barrett's CLO occurred in two patients (11 per cent) after antireflux surgery. The results of this study suggest the superiority of antireflux surgery over pharmacological acid suppression in the control of symptoms and prevention of complications in patients with Barrett's CLO.     

Primary oxalosis mimicking hyperparathyroidism diagnosed after long-term hemodialysis

Primary oxalosis is a rare inborn error of oxalate metabolism. Most cases are discovered in children, but occasionally symptoms begin later in life. Since early deaths in the past were from renal failure, prolonged survival obtained with chronic dialysis allows oxalosis to develop. This paper presents a 38-year-old man with an atypical history of type-I primary hyperoxaluria, not diagnosed until after 5 years of dialysis. Bone biopsy was performed because the biochemical and radiologic features did not seem consistent with a putative diagnosis of secondary hyperparathyroidism. This case emphasizes the clinical heterogeneity of this disorder, and the need for its considerations in the spectrum of dialysis-related bone diseases. It also stresses that bone oxalosis may mimic hyperparathyroidism, especially radiologically. Differential diagnosis is therefore mandatory.     

Comparison of results in endovascular interventions for infrainguinal lesions: claudication versus critical limb ischemia

This study analyzed clinical success, patency, and limb salvage after endovascular repair in patients treated for chronic limb ischemia presenting with claudication versus critical limb ischemia. Between October 2001 and August 2004, 115 patients (mean age 71) underwent endovascular treatment for infrainguinal arterial disease. Techniques included subintimal angioplasty and transluminal angioplasty with or without stents. Lesions were classified according to Transatlantic InterSociety Consensus. Follow-up (mean 11 months) included physical exam, ankle-brachial index, and duplex ultrasound. Patency rates were determined using Kaplan-Meier and compared by log-rank analysis. One hundred ninety-nine lesions were treated in 121 limbs using percutaneous techniques. Comorbidities were similar except higher rates of diabetes mellitus (67% vs 41%, P < 0.001) and chronic renal insufficiency (22% vs 7%, P < 0.05) were found in critical limb ischemia patients. Primary patency for claudicants was 100 per cent, 98 per cent, and 85 per cent at 3, 6, and 12 months and 89 per cent, 80 per cent, and 72 per cent for critical limb ischemia, respectively (P = 0.06). Limb salvage was 91 per cent at 12 months for critical limb ischemia patients. Morbidity was similar between groups, and there was no perioperative mortality. Percutaneous intervention for both claudication and critical limb ischemia provides acceptable 12 month patency with limited morbidity.     

Minimally invasive parathyroid surgery, the Norman 20% rule: is it valid?

The 20 per cent rule proposed by Norman established a guideline using radioactivity in the minimally invasive radioguided parathyroidectomy (MIRP) technique to localize and confirm removal of an abnormal parathyroid gland in patients with primary hyperparathyroidism. If radioactivity in the resected gland was at least 20 per cent of excision site/background radioactivity, the 20 per cent rule was satisfied. Patients meeting these criteria underwent unilateral MIRP without intraoperative parathyroid hormone assay or intraoperative frozen section. The study aim was to independently evaluate the 20 per cent rule in MIRP patients with primary hyperparathyroidism. Using the University of Louisville Parathyroid Database from January 1, 1999 to December 31, 2007, 216 MIRP patients with complete radioguided and postoperative management data were identified. The average percentage of ex vivo parathyroid gland radioactivity compared with excision site/background radioactivity was 107 per cent with a range from 14 to 388 per cent. For 99 per cent (196/198) radioactivity recorded from the excised gland was at least 20 per cent of radioactivity recorded from the excision site. Normocalcemia was documented in 98.5 per cent (195/198) at 12 month follow-up. Our data supports the 20 per cent rule in that in 99 per cent of MIRP patients the resected gland radioactivity was at least 20 per cent of excision site radioactivity allowing localization and confirmation of an overactive gland without intraoperative parathyroid hormone monitoring or tissue analysis.