Predictors of hemodynamic instability during surgery for pheochromocytoma.

BACKGROUND: Resection of pheochromocytoma is often associated with hemodynamic instability (HDI). We examined patient and tumor factors that may influence HDI. The effect of pretreatment with nonselective α blockade phenoxybenzamine (PXB) versus selective α blockade on HDI and outcomes was also evaluated. METHODS: The records of 91 patients who underwent adrenalectomy between 2002 and 2013 were retrospectively reviewed. HDI was determined by number of intraoperative episodes of systolic blood pressure (SBP) > 200 mmHg, those greater than or less than 30 % of baseline, heart rate > 110 bpm, and the need for postoperative vasopressors. Fishers exact, t test and regressions were performed. RESULTS: Among 91 patients, 78 % received PXB, 18 % selective α blockade and 4 % no adrenergic blockade. Patient demographics, tumor factors and surgical approach were similar among the blockade groups. On multivariate analysis, increasing tumor size was associated with a significant rise in the number of episodes of SBP > 30 % [rate ratio (RR) 1.40] and an increased postoperative vasopressor requirement [odds ratio (OR) 1.23]. Open adrenalectomy and use of selective blockade were associated with an increased number of episodes of SBP > 200 mmHg (RR 27.8 and RR 20.9, respectively). Open adrenalectomy was also associated with increased readmissions (OR 12.3), complications (OR 5.6), use of postoperative vasopressors (OR 4.4) and hospital stay (4.6 days longer). There were no differences in other HDI measurements or postoperative outcomes among the blockade groups. CONCLUSIONS: Tumor size, open adrenalectomy, and type of α blockade were associated with intraoperative HDI during pheochromocytoma resection. Selective blockade was associated with significantly more episodes of intraoperative hypertension but no perioperative adverse outcomes.

Is potassium iodide solution necessary before total thyroidectomy for Graves disease?

BACKGROUND: Potassium iodide (KI) has traditionally been used to reduce gland vascularity and diminish blood loss in patients undergoing thyroidectomy for Graves disease (GD). Current American Thyroid Association (ATA) guidelines (Recommendation 22) call for its routine administration in GD but avoidance in toxic multinodular goiter (TMNG). METHODS: A retrospective review (July 2008-May 2012) of perioperative data was performed on 162 patients undergoing total thyroidectomy without preoperative KI and compared to 102 patients with TMNG. Statistical analysis included Student's t test, χ2 test, and multivariate linear regression. RESULTS: Compared to TMNG patients, GD patients had a lower mean age (42.7 vs. 49.6 years, p<0.001) and were less likely to be obese (37 vs. 54%, p=0.047). No patients were provided KI in preparation. GD patients did not differ significantly from TMNG patients with respect to mean estimated blood loss (55.4 vs. 51.5 mL, p=0.773) or mean operative time (131.5 vs. 122.6 min, p=0.084). GD patients had a lower rate of transient hypocalcemia (31 vs. 49%, p=0.004), but the two groups did not statistically differ in rates of prolonged hypocalcemia, temporary recurrent laryngeal nerve (RLN) palsy, prolonged RLN paralysis, or hematoma formation. CONCLUSIONS: Although current ATA recommendations for the management of GD call for routine use of KI before thyroidectomy, this large series demonstrates no appreciable detriment to patient outcomes when this goal is not met.

Toxic nodular goiter and cancer: a compelling case for thyroidectomy.

BACKGROUND: Recent American Thyroid Association guidelines call for thyroidectomy or (131)I (Recommendation 31) in managing hyperthyroidism due to toxic nodular goiter (TNG). Concern for concomitant malignancy favors surgery. A 3 % thyroid cancer incidence in TNG patients has been reported, yet recent studies suggest this rate is underestimated. This multi-institutional study examined cancer incidence in TNG patients referred to surgery. METHODS: Patients referred for thyroidectomy at three tertiary-care institutions were included (2002-2011). Patients with concurrent indeterminate or malignant diagnosis by fine-needle aspiration (FNA) were excluded. Cancer incidence in TNG patients was determined. Fisher's exact and chi-square tests and nonparametric t tests were used. RESULTS: Among 2,551 surgically treated patients, 164 had TNG (6.4 %). Median age at presentation was 49.7 years, and 86 % were female. Overall cancer incidence was 18.3 % (30 of 164), and rates were not significantly different between institutions. A significantly greater cancer rate was noted in toxic multinodular goiter versus single toxic nodule patients (21 vs. 4.5 %, P < 0.05). Mean tumor size was 0.71 cm (range 0.1-1.5 cm; 23 % ≥1 cm). Most patients underwent total or near-total thyroidectomy. There were no significant differences in tumor sizes among institutions (P > 0.05). No significant cancer association was noted with age, preoperative dominant nodule size, lymphocytic thyroiditis or preoperative FNA (P > 0.05). CONCLUSIONS: These data demonstrate a higher than expected incidental cancer rate in TNG patients compared to historical reports (18.3 vs. 3 %). This higher cancer incidence may alter the risk/benefit analysis regarding TNG treatment. This information should be provided to TNG patients before decision making regarding treatment.

Changing intraoperative parathyroid hormone collection sites from peripheral to central does not affect predictive accuracy during minimally invasive parathyroidectomy.

BACKGROUND: Intraoperative parathyroid hormone (ioPTH) monitoring (IPM) is vital to minimally invasive parathyroidectomy. Techniques vary in assay sampling, potentially affecting predictive accuracy of operative success. Initial guidelines were established using peripheral sites, but central sites may be preferred or necessary when peripheral access is not feasible. We hypothesize that changing collection sites from preexcision peripheral sites to postexcision central sites would not affect IPM accuracy. METHODS: Analysis of 64 consecutive patients who underwent parathyroidectomy for primary hyperparathyroidism was undertaken. PTH assays were collected simultaneously from a peripheral vein (PV) and central vein (CV) preexcision and at a 10-min interval after initial parathyroid excision. IPM success was defined as PTH decrease ≥50% 10 min after initial excision. Predictive accuracy was determined by the need to resect another abnormal gland and biochemical normalization in the postoperative clinic. Receiver operating characteristic (ROC) method with area under the curve (AUC) compared diagnostic accuracy of different assay approaches. RESULTS: Centrally, a statistically higher mean pre- and postexcision ioPTH of 391 pg/ml and 58 pg/ml was found compared with peripheral means of 156 pg/ml and 49 pg/ml, respectively (p < 0.001). The AUC when changing from a PV preexcision to a CV postexcision ioPTH was 0.89, comparable to AUC for peripheral or central assay collections alone (AUC = 0.83 and 0.85, respectively). CONCLUSIONS: This study suggests that altering collection sites does not alter assay validity. In cases where peripheral sampling is compromised, changing from a peripheral to central sites will not likely alter the predictive accuracy of IPM significantly.

An international perspective on ultrasound training and use for thyroid and parathyroid disease.

BACKGROUND: Use of ultrasound (USN) by endocrine surgeons has dramatically increased. Presently, optimal training and certification requirements have not been standardized at any level (resident/fellow/attending). We sought to define the types of USN training endocrine surgeons receive and how USN is employed in practice. We hypothesized that in more recent years fellowship-trained endocrine surgeons were more likely to receive formal training in the use of USN during their endocrine surgery fellowship. METHODS: A survey link was sent via email to a large group of endocrine surgeons around the world asking about the settings in which they received USN training, the type of instruction received, current use of USN, and other various questions. chi(2) analysis was performed and P < 0.05 was considered significant. RESULTS: One hundred twenty-one surveys were collected from respondents in 27 countries. Median time from completion of residency to the present was 17 years (range = 2-49). Fifty-nine percent of both fellowship- and nonfellowship-trained endocrine surgeons currently use USN in their practice. Of those currently performing USN, 38% reported no USN training of any kind (47% international vs. 23% United States). USN experience among international and U.S. residents was not different (P = 0.27). Fifty-nine percent of respondents reported completing an endocrine surgery fellowship; of those, 85% reported no formal USN training. Forty-one percent reported not being comfortable performing USN at the completion of their endocrine surgery fellowships, requiring the presence of someone else to assist with the exam. CONCLUSIONS: USN training among endocrine surgeons varies widely around the world. Despite an increase in the number of formal endocrine surgery fellowships offered, it does not appear that the number with formal USN training and certification has increased. Formal USN certification is achieved in only a minority of cases among practicing endocrine surgeons. It is currently unknown whether there is a difference in competency between endocrine surgeons with formal versus informal USN training.

Validation of strain gauges as a method of measuring precision of fit of implant bars.

UNLABELLED: Multiple articles in the literature have used strain gauges to estimate the precision of fit of implant bars. However, the accuracy of these measurements has not been fully documented. The purpose of this study was to evaluate the response of strain gauges to known amounts of misfit in an implant bar. This is an important step in validation of this device. MATERIALS: A steel block was manufactured with five 4.0-mm externally hexed implant platforms machined into the block 7-mm apart. A 1.4-cm long gold alloy bar was cast to fit 2 of the platforms. Brass shims of varying thickness (150, 300, and 500 microm) were placed under one side of the bar to create misfit. A strain gage was used to record strain readings on top of the bar, one reading at first contact of the bar and one at maximum screw torque. Microgaps between the bar and the steel platforms were measured using a high-precision optical measuring device at 4 points around the platform. The experiment was repeated 3 times. Two-way analysis of variance and linear regression were used for statistical analyses. RESULTS: Shim thickness had a significant effect on strain (P < 0.0001). There was a significant positive correlation between shim thickness and strain (R(2) = 0.93) for strain at maximum torque, and for strain measurements at first contact (R(2) = 0.91). Microgap measurements showed no correlation with increasing misfit. CONCLUSIONS: Strain in the bar increased significantly with increasing levels of misfit. Strain measurements induced at maximum torque are not necessarily indicative of the maximum strains experienced by the bar. The presence or absence of a microgap between the bar and the platform is not necessarily indicative of passivity. These data suggest that microgap may not be clinically reliable as a measure of precision of fit.

Comparison of the passivity between cast alloy and laser-welded titanium overdenture bars.

PURPOSE: The purpose of this study was to investigate the fit of cast alloy overdenture and laser-welded titanium-alloy bars by measuring induced strain upon tightening of the bars on a master cast as well as a function of screw tightening sequence. MATERIALS AND METHODS: Four implant analogs were secured into Type IV dental stone to simulate a mandibular edentulous patient cast, and two groups of four overdenture bars were fabricated. Group I was four cast alloy bars and Group II was four laser-welded titanium bars. The cast alloy bars included Au-Ag-Pd, Pd-Ag-Au, Au-Ag-Cu-Pd, and Ag-Pd-Cu-Au, while the laser-welded bars were all Ti-Al-V alloy. Bars were made from the same master cast, were torqued into place, and the total strain in the bars was measured through five strain gauges bonded to the bar between the implants. Each bar was placed and torqued 27 times to 30 Ncm per screw using three tightening sequences. Data were processed through a strain amplifier and analyzed by computer using StrainSmart software. Data were analyzed by ANOVA and Tukey's post hoc test. RESULTS: Significant differences were found between alloy types. Laser-welded titanium bars tended to have lower strains than corresponding cast bars, although the Au-Ag-Pd bar was not significantly different. The magnitudes of total strain were the least when first tightening the ends of the bar. CONCLUSIONS: The passivity of implant overdenture bars was evaluated using total strain of the bar when tightening. Selecting a high modulus of elasticity cast alloy or use of laser-welded bar design resulted in the lowest average strain magnitudes. While the effect of screw tightening sequence was minimal, tightening the distal ends first demonstrated the lowest strain, and hence the best passivity.

Urea functionalization of ultrasound-treated biochar: A feasible strategy for enhancing heavy metal adsorption capacity.

The main objective of a series of our researches is to develop a novel acoustic-based method for activation of biochar. This study investigates the capability of biochar in adsorbing Ni(II) as a hazardous contaminant and aims at enhancing its adsorption capacity by the addition of extra nitrogen and most probably phosphorous and oxygen containing sites using an ultrasono-chemical modification mechanism. To reach this objective, biochar physically modified by low-frequency ultrasound waves (USB) was chemically treated by phosphoric acid (H3PO4) and then functionalized by urea (CO(NH2)2). Cavitation induced by ultrasound waves exfoliates and breaks apart the regular shape of graphitic oxide layers of biochar, cleans smooth surfaces, and increases the porosity and permeability of biochar's carbonaceous structure. These phenomena synergistically combined with urea functionalization to attach the amine groups onto the biochar surface and remarkably increased the adsorption of Ni(II). It was found that the modified biochar could remove > 99% of 100 mg Ni(II)/L in only six hours, while the raw biochar removed only 73.5% of Ni(II) in twelve hours. It should be noted that physical treatment of biochar with ultrasound energy, which can be applied at room temperature for a very short duration, followed by chemical functionalization is an economical and efficient method of biochar modification compared with traditional methods, which are usually applied in a very severe temperature (>873 K) for a long duration. Such modified biochars can help protect human health from metal-ion corrosion of degrading piping in cities with aging infrastructure.

Innovative surgical guidance for label-free real-time parathyroid identification.

BACKGROUND: Difficulty in identifying the parathyroid gland during neck operations can lead to accidental parathyroid gland excisions and postsurgical hypocalcemia. A clinical prototype called as PTeye was developed to guide parathyroid gland identification using a fiber-optic probe that detects near-infrared autofluorescence from parathyroid glands as operating room lights remain on. An Overlay Tissue Imaging System was designed concurrently to detect near-infrared autofluorescence and project visible light precisely onto parathyroid gland location. METHODS: The PTeye and the Overlay Tissue Imaging System were tested in 20 and 15 patients, respectively, and a modified near-infrared imaging system was investigated in 6 patients. All 41 patients underwent thyroidectomy or parathyroidectomy. System accuracy was ascertained with surgeon's visual confirmation for in situ parathyroid glands and histology for excised parathyroid glands. RESULTS: There was no observable difference between near-infrared autofluorescence of healthy and diseased parathyroid glands. The PTeye identified 98% of the parathyroid gland, whereas the near-infrared imaging system and the Overlay Tissue Imaging System identified 100% and 97% of the parathyroid glands, respectively. CONCLUSION: The PTeye can guide in real-time parathyroid gland identification even with ambient operating room lights. The near-infrared imaging system performs parathyroid gland imaging with high sensitivity, whereas the Overlay Tissue Imaging System enhances parathyroid gland visualization directly within the surgical field without requiring display monitors. These label-free technologies can be valuable adjuncts for identifying parathyroid glands intraoperatively.

The effect of etching technique on the retention of adhesively cemented prefabricated dowels.

PURPOSE: To determine if etching technique influences the bond strength of resin cement to root canal dentin. MATERIALS AND METHODS: Fifty-five extracted teeth were endodontically treated, dowel space prepared, and divided into five groups. Each group was treated with different etchant consistencies: acid gel, semi-gel, low-viscosity gel, liquid, and a self-etching primer. After dowel cementation, four sections were removed from each root and a push-out test was performed. RESULTS: Significant effects were found for etching procedure and for location within the root canal. The apical segment produced the lowest bond strength. Self-etching primer showed the highest bond strength. CONCLUSIONS: The consistency of etchant material influenced the bond strength of a prefabricated dowel in the canal.

Protracted Hypocalcemia following 3.5 Parathyroidectomy in a Kidney Pancreas Recipient with a History of Robotic-Assisted Roux-en-Y Gastric Bypass.

BACKGROUND: Hypocalcemia is a frequent complication of parathyroidectomy for secondary/tertiary hyperparathyroidism. In patients with a history of prior Roux-en-Y gastric bypass (RYGBP), changes in nutritional absorption make management of hypocalcemia after parathyroidectomy difficult. CASE REPORT: A 41-old-year morbidly obese female with c-peptide negative diabetes mellitus and renal failure had RYGBP. Following significant weight loss she underwent simultaneous pancreas-kidney transplantation. She had excellent transplant graft function but developed tertiary hyperparathyroidism with calciphylaxis. She underwent resection of 3.5 glands leaving a small, physiologic remnant remaining in situ at the left inferior position. She was discharged on postoperative day one in good condition, asymptomatic with serum calcium of 7.6 mg/dL and intact PTH of 12 pg/mL. The patient had to be readmitted on postoperative day #14 for severe hypocalcemia of 5.0 mg/dl and ionized calcium 2.4 mg/dl. She required intravenous calcium infusion to achieve calcium levels of >6.5 mg/dl. Long-term treatment includes 5 g of elemental oral calcium TID, vitamin D, and hydrochlorothiazide. She remains in the long term on high-dose medical therapy with normal serum calcium levels and PTH levels around 100 pg/mL. DISCUSSION: Our patient's protracted hypocalcemia originates from a combination of 3.5 gland parathyroidectomy, altered intestinal anatomy post-RYGBP, and potentially her pancreas transplant causing additional metabolic derangement. Alternative bariatric procedures such as sleeve gastrectomy may be more suitable for patients with renal failure or organ transplants in whom adequate absorption of vitamins, minerals, and drugs such as immunosuppressants is essential.

Complications of percutaneous nephrostomy in a district general hospital.

OBJECTIVE: Percutaneous nephrostomy (PCN) is one of the commonest procedures performed. There are currently no European recommendations on the accepted rate of complications. The aim of the present study is to report the complication rate of PCN with the specific emphasis on sepsis and septic shock, the causative organisms, sensitivities to antibiotics, and associated risk factors. MATERIAL AND METHODS: Retrospectively collected data on patients undergoing acute or elective PCN at the Department of Radiology, Countess of Chester Hospital (COCH), in the UK between January 2014 and December 2016 were analyzed after the study was approved by Local Audit Department at COCH. RESULTS: A total of 66 patients underwent 90 acute or elective PCNs. Three patients developed major post-PCN complication (two patients developed septic shock and the third suffered a hemorrhagic episode requiring blood transfusion). Nephrostomy tube complications (blockage, leaking, fracturing and kinking of the catheter) occurred in 4 patients. Complications were more common when the PCN was performed out of working hours (71.4% [10/14], and 17.3% [9/52] for PCNs performed within, and out of working hours, respectively: p<0.001). The age of the patients did not seem to correlate with the development of complications (p<0.001). Of all 25 patients, in whom septicemia was diagnosed prior to PCN tube insertion, 12 developed septic shock and 13 had signs of sepsis for longer than 24 h. Fifteen patients had positive urine cultures. The most common organism isolated was Escherichia coli. Blood culture isolates included: Escherichia coli, Eggerthella lenta, Enterococcus, Proteus mirabilis, Pseudomonas aeruginosa and Streptococcus pneumonia. CONCLUSION: Our complication rates were within United States proposed target ranges. Our data may help to serve as a baseline for outcome targets in the European centres.

Developing a Clinical Prototype to Guide Surgeons for Intraoperative Label-Free Identification of Parathyroid Glands in Real Time.

BACKGROUND: Patients undergoing thyroidectomy may have inadvertent damage or removal of the parathyroid gland(s) due to difficulty in real-time parathyroid identification. Near-infrared autofluorescence (NIRAF) has been demonstrated as a label-free modality for intraoperative parathyroid identification with high accuracy. This study presents the translation of that approach into a user-friendly clinical prototype for rapid intraoperative guidance in parathyroid identification. METHODS: A laboratory (lab)-built spectroscopy system that measures NIRAF in tissue was evaluated for identifying parathyroid glands in vivo across 162 patients undergoing thyroidectomy and/or parathyroidectomy. Based on these results, a clinical prototype called PTeye was designed with a user-friendly interface and subsequently investigated in 35 patients. The performance of the lab-built system and the clinical prototype were concurrently compared side by side by a single user with 20 patients in each group. The influence of (i) intrapatient and interpatient variability of NIRAF in thyroid and parathyroid glands and (ii) thyroid and parathyroid pathology on intraoperative parathyroid identification were investigated. The effect of blood on NIRAF intensity of parathyroid and thyroid was tested ex vivo with the PTeye system to assess if a hemorrhagic surgical field would affect parathyroid identification. Accuracy of both systems were determined by correlating the acquired data with either visual confirmation by a surgeon for unexcised parathyroid glands or histology reports for excised parathyroid glands. RESULTS: The overall accuracy of the lab-built system in guiding parathyroid identification was 92.5%, while the PTeye system achieved an accuracy of 96.1%. Unlike the lab-built system, the PTeye could guide parathyroid identification even as the operating room lights remained on and required only 25% of the laser power used by the lab-built setup. Parathyroid glands had elevated NIRAF intensity compared to thyroid and other neck tissues, regardless of thyroid or parathyroid pathology. Blood did not seem to affect tissue NIRAF measurements obtained with both systems. CONCLUSION: In this study, the clinical prototype PTeye demonstrated high accuracy for label-free intraoperative parathyroid identification. The intuitive interface of the PTeye that can guide in identifying parathyroid tissue in the presence of ambient room lights suggests that it is a reliable and easy-to-use tool for surgical personnel.

Central venous sampling for intraoperative parathyroid hormone monitoring: are peripheral guidelines applicable?

Intraoperative parathyroid hormone (PTH) monitoring has become an integral adjunct to minimally invasive parathyroidectomy. Guidelines for predicting therapeutic excision of all hyperactive parathyroid tissue have been routinely based on peripheral blood samples drawn at various time intervals. Whether these same guidelines can be used to predict success based on central blood draws has not been established. The authors wanted to evaluate whether peripheral criteria were applicable when PTH levels were drawn from a central location. Simultaneous peripheral venous (PV) and central venous (CV) PTH samples were drawn from 64 patients undergoing cervical exploration for primary hyperparathyroidism. Median preexcision PTH was significantly higher centrally at 165 pg/mL (interquartile range [IQR], 101-391 pg/mL) versus peripherally 102 pg/mL (interquartile range, 73-156 pg/mL, P < 0.0001). Postexcision PTH was slightly greater in CV (38 pg/mL; IQR, 24-62) than in PV (29 pg/mL; IQR, 22-51; P < 0.0001). The decrease in intraoperative PTH was compared after excision of an initial gland. Fifty-four of the 64 patients had all hyperfunctioning parathyroid tissue removed after initial gland resection. Pre- to postexcision ratios for CV and PV were compared using receiver operating characteristic curve methods, and summarized by area under the curve (AUC). PV (AUC = 0.85) appears to be a slightly more sensitive discriminator than CV (AUC = 0.83), although the difference is not statistically significant (P = 0.5). Despite higher absolute values for CV, both peripheral and central sample sites accurately predict outcomes based on established guidelines for intraoperative PTH monitoring.

Hardness and wear resistance of two resin composites cured with equivalent radiant exposure from a low irradiance LED and QTH light-curing units.

PURPOSE: To measure and compare three-body wear and Vickers hardness at depths of 0 mm and 2 mm in two composite resin materials cured with either a low irradiance light emitting diode (LED) or a quartz tungsten halogen (QTH) light-curing unit (LCU) in which exposure duration with the LED was increased to deliver equivalent radiant exposure in the 450-490 nm wavelength range. METHODS: The VIP QTH and Freelight LED LCU's were obtained and the emission spectrum of each was determined using a Spectra Pro 750 spectrograph. Irradiance in the 450-490 nm range for each LCU was determined by calculating the area under the spectral curve. Curing of two composite resins (Z100 and Esthet-X) with equivalent radiant exposure within this prescribed wavelength range was achieved by increasing the irradiation time of the LED 33% from 30-40 seconds to compensate for its lower irradiance (Table 1). The resulting radiant exposure of 8.40 J/cm2 was roughly equivalent to the radiant exposure produced in 30 seconds by the QTH LCU (8.67 J/cm2). The cured specimens were polished with progressively fine wet silicon carbide papers to 600 grit and stored in distilled water at 37 degrees C for 24 hours prior to evaluating hardness and wear. Indentations for Vickers hardness testing were produced by applying a 0.5 kg load with a 15-second dwell time. Equivalent degree of cure was established indirectly through Vickers hardness numbers for the top and bottom surface of 2 mm thick disks of each material cured with each light (N = 3/group). Hardness ratios were computed by dividing mean bottom hardness by mean top hardness within each group. Three-body wear testing (N = 10/group) was performed on similarly fabricated specimens with a mechanical wear device using 44 microm unpolymerized PMMA beads as a simulated food bolus. The composite resin samples opposed spherical, stainless steel styli. A 75 N contact force was applied at 1.2 Hz for 100,000 cycles. Profilometry was used to quantify localized wear of the resin. Multivariate ANOVA and the Tukey-Kramer post hoc test (alpha = 0.05) were used to assess differences in hardness and wear of the materials. RESULTS: With respect to hardness, no difference was noted between top and bottom specimen sides based on material or curing method. Specimens cured using the LED exhibited hardness ratios approaching unity. No significant difference in hardness was found for the main effect of light used, but the main effect of material was highly significant. This was primarily because Z100 cured with the LED demonstrated statistically higher hardness than the other three groups, which were statistically similar. No significant difference in wear was found based on the light used, with the lowest mean wear seen in Z100 cured with the LED. Overall, Z100 exhibited significantly greater surface hardness (P < 0.001) and significantly less wear (P < 0.01) compared to Esthet-X

Establishing the clinical utility of autofluorescence spectroscopy for parathyroid detection.

BACKGROUND: The inability of surgeons to identify parathyroid glands accurately during cervical endocrine surgery hinders patients from achieving postoperative normocalcemia. An intrinsic, near-infrared fluorescence method was developed for real-time parathyroid identification with high accuracy. This study assesses the clinical utility of this approach. METHODS: Autofluorescence measurements were obtained from 137 patients (264 parathyroid glands) undergoing parathyroidectomy and/or thyroidectomy. Measurements were correlated to disease state, calcium levels, parathyroid hormone, vitamin D levels, age, sex, ethnicity, and body mass index. Statistical analysis identified which factors affect parathyroid detection. RESULTS: High parathyroid fluorescence was detected consistently and showed wide variability across patients. Near-infrared fluorescence was used to identify 256 of 264 (97%) of glands correctly. The technique showed high accuracy over a wide variety of disease states, although patients with secondary hyperparathyroidism demonstrated confounding results. Analysis revealed body mass index (P < .01), disease state (P < .01), vitamin D (P < .05), and calcium levels (P < .05) account greatly for variability in signal intensity. Age, sex, parathyroid hormone, and ethnicity had no effect. CONCLUSION: This intrinsic fluorescence-based intraoperative technique can detect nearly all parathyroid glands accurately in real time. Its discrimination capacity is largely unlimited by patient variables, but several factors affect signal intensity. These results demonstrate potential clinical utility of optical guidance for parathyroid detection.

Xanthoma of the urinary bladder: a rare benign condition which may be mistaken for malignancy.

A 77-year-old man was referred with a history of recurrent urinary tract infections and a raised prostate-specific antigen. He was found to have an atypical lesion of the urinary bladder on cystoscopic examination. A preoperative MRI study suggested no evidence of malignancy and histology was consistent with urinary bladder xanthoma. This is a benign and exceedingly rare condition which requires no further treatment or follow-up. Patients should, however, have a lipid profile measured. Our case illustrates the use of MRI as an adjunct to aid operative planning. Although not essential, it may help to avoid an over aggressive initial resection in more precarious areas of the urinary bladder.

Influence of adrenal pathology on perioperative outcomes: a multi-institutional analysis.

BACKGROUND: Endoscopic or open adrenalectomies are performed for variable pathologies. We investigated if adrenal pathology affects perioperative outcomes independent of operative approach. METHODS: A multi-institutional retrospective review of 345 adrenalectomies was performed. A multivariate analysis was utilized. RESULTS: Pathology groups included benign non-pheochromocytoma tumors (50.4%), pheochromocytomas (41%), adrenocortical carcinomas (5.2%), and metastatic tumors (3.4%). Controlling for age, body mass index, tumor size, procedure type, and pathology, pheochromocytomas exhibited greater blood loss (92 mL more, P = .007) and operative times (33 min more, P < .001) than benign non-pheochromocytoma tumors. Metastatic tumors demonstrated longer operative times (53 min more, P = .013). Open adrenalectomy was associated with greater blood loss (396 mL more, P = .001), transfusion requirement (P = .021), operative times (79 min more, P < .001), hospital stay (6.6 days more, P < .001) and complications (P < .001) when compared with endoscopic adrenalectomy. CONCLUSIONS: The type of adrenal pathology appears to influence blood loss and operative time but not complications in patients undergoing adrenalectomy. Open adrenalectomy remains a major driver of adverse perioperative outcomes.

Label-free intraoperative parathyroid localization with near-infrared autofluorescence imaging.

CONTEXT: The inability to accurately localize the parathyroid glands during parathyroidectomy and thyroidectomy procedures can prevent patients from achieving postoperative normocalcemia. There is a critical need for an improved intraoperative method for real-time parathyroid identification. OBJECTIVE: The objective of the study was to test the accuracy of a real-time, label-free technique that uses near-infrared (NIR) autofluorescence imaging to localize the parathyroid. SETTING: The study was conducted at the Vanderbilt University endocrine surgery center. SUBJECTS AND METHODS: Patients undergoing parathyroidectomy and/or thyroidectomy were included in this study. To validate the intrinsic fluorescence signal in parathyroid, point measurements from 110 patients were collected using NIR fluorescence spectroscopy. Fluorescence imaging was performed on 6 patients. Imaging contrast is based on a previously unreported intrinsic NIR fluorophore in the parathyroid gland. The accuracy of fluorescence imaging was analyzed in comparison with visual assessment and histological findings. MAIN OUTCOME MEASURE: The detection rate of parathyroid glands was measured. RESULTS: The parathyroid glands in 100% of patients measured with fluorescence imaging were successfully detected in real time. Fluorescence images consistently showed 2.4 to 8.5 times higher emission intensity from the parathyroid than surrounding tissue. Histological validation confirmed that the high intrinsic fluorescence signal in the parathyroid gland can be used to localize the parathyroid gland regardless of disease state. CONCLUSION: NIR fluorescence imaging represents a highly sensitive, real-time, label-free tool for parathyroid localization during surgery. The elegance and effectiveness of NIR autofluorescence imaging of the parathyroid gland makes it highly attractive for clinical application in endocrine surgery.

Impact of surgical mentorship on retroperitoneoscopic adrenalectomy with comparison to transperitoneal laparoscopic adrenalectomy.

Retroperitoneoscopic adrenalectomy (RA) provides a direct approach to the adrenal gland. RA represents a complex approach with unique orientation that is less intuitive. The authors objectively evaluated the impact of mentorship on the performance of RA and also compared it with laparoscopic adrenalectomy (LA). After implementing the use of RA, a retrospective review of the operative experience of two high-volume endocrine surgeons was performed. Both surgeons participated in a hands-on RA mentorship. Clinical presentation and perioperative outcomes were compared. Subgroup analysis was used to compare RA pre- and postmentorship and with LA. Sixty-one LAs and 31 RAs were included in the analysis. The mean operative time was 115 for LA versus 90 minutes for RA (P = 0.002). Blood loss was greater for LA versus RA (56 vs 22 mL; P = 0.001). Length of stay (LOS) for LA was 2.2 versus 1.5 days for RA (P = 0.029). Ten patients were treated by RA in the prementorship era versus 21 in the postmentorship era. The mean operative time for the prementorship group was 118 minutes, which decreased to 77 minutes postmentorship (P < 0.0001). LOS also decreased from 2.0 to 1.2 days (P = 0.04) in the postmentorship era. RA demonstrates a shorter operative time, less blood loss, and decrease length of hospital stay as compared with standard LA. After proper mentorship and patient selection, RA may represent a superior option for removal of small, benign adrenal tumors.