Post-PET ultrasound improves specificity of 18F-FDG-PET for recurrent differentiated thyroid cancer while maintaining sensitivity.

BACKGROUND: Positron emission tomography (PET) using fluor-18-deoxyglucose (18F-FDG) with or without computed tomography (CT) is generally accepted as the most sensitive imaging modality for diagnosing recurrent differentiated thyroid cancer (DTC) in patients with negative whole body scintigraphy with iodine-131 (I-131). PURPOSE: To assess the potential incremental value of ultrasound (US) over 18F-FDG-PET-CT. MATERIAL AND METHODS: Fifty-one consecutive patients with suspected recurrent DTC were prospectively evaluated using the following multimodal imaging protocol: (i) US before PET (pre-US) with or without fine needle biopsy (FNB) of suspicious lesions; (ii) single photon emission computed tomography (≥3 GBq I-131) with co-registered CT (SPECT-CT); (iii) 18F-FDG-PET with co-registered contrast-enhanced CT of the neck; (iv) US in correlation with the other imaging modalities (post-US). Postoperative histology, FNB, and long-term follow-up (median, 2.8 years) were taken as composite gold standard. RESULTS: Fifty-eight malignant lesions were identified in 34 patients. Forty lesions were located in the neck or upper mediastinum. On receiver operating characteristics (ROC) analysis, 18F-FDG-PET had a limited lesion-based specificity of 59% at a set sensitivity of 90%. Pre-US had poor sensitivity and specificity of 52% and 53%, respectively, increasing to 85% and 94% on post-US, with knowledge of the PET/CT findings (P < 0.05 vs. PET and pre-US). Multimodal imaging changed therapy in 15 out of 51 patients (30%). CONCLUSION: In patients with suspected recurrent DTC, supplemental targeted US in addition to 18F-FDG-PET-CT increases specificity while maintainin sensitivity, as non-malignant FDG uptake in cervical lesions can be confirmed.

Dialysis shunt-associated steal syndrome (DASS) following brachial accesses: the value of fistula banding under blood flow control.

BACKGROUND: Dialysis shunt-associated steal syndrome (DASS) is a rare complication of hemodialysis access (HA) which preferably occurs in brachial fistulas. Treatment options are discussed controversially. Aim of this study was to evaluate flow-controlled fistula banding. MATERIALS AND METHODS: Patients treated between 2002 and 2006 were included in this prospective survey. According to a classification we established, patients were typed DASS I-III (I: short history, no dermal lesions; II: long history, skin lesions; III: long history, gangrene). Surgical therapy was HA banding including controlled reduction (about 50% of initial flow) of HA blood flow (patients type I and II). Patients with type III underwent closure of the HA. RESULTS: In 15 patients with relevant DASS, blood-flow-controlled banding was performed. In ten patients (all type I), banding led to restitution of the hand function while preserving the HA. In five patients (all type II), banding was not successful; in two patients, closure of the HA was performed eventually. In five patients (type III), primary closure of the HA was performed. Four patients with DASS type II but only two with DASS type I had diabetes mellitus (p = 0.006). CONCLUSIONS: Banding under blood flow control resulting in an approximately 50% reduction in the initial blood flow is an adequate therapeutic option in patients with brachial HA and type I-DASS. In type II-DASS, banding does not lead to satisfying results, more complex surgical options might be more successful. Diabetes is associated with poor HA outcome in case of DASS.

Frequency of transient ipsilateral vocal cord paralysis in patients undergoing carotid endarterectomy under local anesthesia.

BACKGROUND: Especially because of improvements in clinical neurologic monitoring, carotid endarterectomy done under local anesthesia has become the technique of choice in several centers. Temporary ipsilateral vocal nerve palsies due to local anesthetics have been described, however. Such complications are most important in situations where there is a pre-existing contralateral paralysis. We therefore examined the effect of local anesthesia on vocal cord function to better understand its possible consequences. METHODS: This prospective study included 28 patients undergoing carotid endarterectomy under local anesthesia. Vocal cord function was evaluated before, during, and after surgery (postoperative day 1) using flexible laryngoscopy. Anesthesia was performed by injecting 20 to 40 mL of a mixture of long-acting (ropivacaine) and short-acting (prilocaine) anesthetic. RESULTS: All patients had normal vocal cord function preoperatively. Twelve patients (43%) were found to have intraoperative ipsilateral vocal cord paralysis. It resolved in all cases < or =24 hours. There were no significant differences in operating time or volume or frequency of anesthetic administration in patients with temporary vocal cord paralysis compared with those without. CONCLUSION: Local anesthesia led to temporary ipsilateral vocal cord paralysis in almost half of these patients. Because pre-existing paralysis is of a relevant frequency (up to 3%), a preoperative evaluation of vocal cord function before carotid endarterectomy under local anesthesia is recommended to avoid intraoperative bilateral paralysis. In patients with preoperative contralateral vocal cord paralysis, surgery under general anesthesia should be considered.

Total parathyroidectomy without autotransplantation for renal hyperparathyroidism: experience with a qPTH-controlled protocol.

BACKGROUND: Controversy regarding the optimal surgical treatment for secondary hyperparathyroidism (sHPT) continues. Subtotal parathyroidectomy (PTX) with a small remnant and total parathyroidectomy with autotransplantation prevail, although impaired by considerable recurrence rates. Concerns about postoperative management and long-term supplementation prevent broader acceptance of total parathyroidectomy without autotransplantation. MATERIALS AND METHODS: The standardized surgical procedure with intraoperative PTH assessment (qPTH) included cervical thymectomy, histological proof of four parathyroid specimens and obligatory cryopreservation of parathyroid tissue in all 23 patients undergoing total PTX without autotransplantation. Whenever qPTH did not normalize, complete cervical exploration of ectopic sites was performed. Another 64 patients with subtotal PTX for sHPT served as comparison for the postoperative course. RESULTS: There were 13 primary and 10 completion (5 persistent, 5 recurrent sHPT) total PTX with 14 concurrent thyroid resections performed. Mean preoperative PTH was 1.351 pg/ml (12-72 pg/ml) and serum calcium was 2.5 mmol/l (2.25-2.5 mmol/l). PTH showed intraoperative normalization in 15 patients and a 50% PTH reduction from preoperative values in all. Postoperative course was not significantly different from the subtotal PTX group and showed PTH within the normal range for 5 patients (4 < 35 pg/ml), 7 with PTH < 12 pg/ml, and 4 without measurable PTH. In 4 patients PTH did not normalize postoperatively. Serum calcium levels were below normal in all patients: < 2.25 mmol/l in 9, < 2.00 mmol/l in 7, and <1.8 mmol/l in 6 patients. Only 1 patient required intermittent early postoperative i.v. calcium supplementation, 6 patients received oral calcium and vitamin D supplement for low calcium levels, but no severe hypocalcemic symptoms were encountered. Mean postoperative hospital stay was 5 days. No recurrent laryngeal nerve palsies were encountered. Complications were two cervical bleedings following postoperative hemodialysis requiring evacuation. CONCLUSIONS: Total PTX without autotransplantation proves to be an equally safe and successful procedure for sHPT as subtotal PTX or total PTX with autotransplantation. Measurable PTH after total PTX as demonstrated in this study, supports the idea of uncontrollable isolated cell nests that are inevitably prone to stimulated growth with time. Therefore, total PTX is superior with regard to prevention of recurrence. Adequate supplementation with calcium and vitamin D, often necessary after subtotal PTX to suppress inadequate PTH and protect from recurrence, will prevent severe hypocalcemia and with the modern aluminium-diminishing dialysis regimen, development of adynamic bone disease appears less likely than feared. If necessary, cryopreserved parathyroid tissue can be autotransplanted on demand.