Impact of great auricular nerve sacrifice on sensory disturbance after parotidectomy.

PURPOSE: To investigate the association between great auricular nerve (GAN) sacrifice during parotidectomy and postoperative sensory disturbance. MATERIALS AND METHODS: Patients who underwent parotidectomy between November 2016 and May 2020 at a single academic institution were included in this retrospective chart review. Operative notes were reviewed to determine incidence of GAN sacrifice. Prevalence of patient-reported sensory complaints in the GAN distribution and time to spontaneous resolution of symptoms were assessed. RESULTS: Of 305 parotidectomy patients, 111 (36.4%) endorsed complaints of postoperative sensory disturbances in the GAN distribution typically characterized by numbness or shooting pains. GAN sacrifice was present in 9 (8.1%) of 111 patients who experienced sensory disturbances compared to 9 (4.6%) who reported no sensory disturbances (p > 0.05). Twenty-five patients (32.5%) experienced spontaneous resolution of symptoms at their most recent follow-up at a mean of 6.2 months after onset of symptoms. Of those that experienced a sensory disturbance, GAN preservation was not significantly associated with likelihood of spontaneous recovery (p > 0.05). CONCLUSIONS: We report the largest series to date of post-operative sensory disturbance in parotidectomy patients as it relates to intraoperative GAN sacrifice. Although the relationship between GAN sacrifice and the incidence of postoperative sensory disturbance and its subsequent resolution were not significant, we continue to advocate for GAN preservation to reduce incidence of postoperative sensory disturbances.

Rate of Fat Graft Volume Loss After Parotidectomy.

BACKGROUND: Reconstruction after parotidectomy can include fat grafting, which allows for symmetry, but grafts have demonstrated volume loss over time. OBJECTIVES: To provide quantitative evidence for the rate of volume loss of fat grafts. METHODS: Patients who received parotidectomy with fat graft reconstruction at a single institution from August 2016 to October 2020 were identified. Relationships between clinical factors and the logarithmic rate of fat graft volume loss were analyzed. RESULTS: Twelve patients received parotidectomy, fat graft reconstruction, and underwent a postoperative magnetic resonance imaging (MRI) scan. Rate of fat graft volume loss was a mean of 1.8% per month (standard deviation [SD]: 2.1% per month). Total parotid fat graft volume loss was a mean of 57.4% (SD: 67.5%). The mean follow-up time was 35.5 months (range: 9-89.8 months). Correlations between body mass index (BMI), history of smoking, and history of alcohol consumption and logarithmic rates of fat graft volume loss were increased but not significantly. CONCLUSIONS: Fat grafts have the potential of 60% volume loss at approximately 1 year. If there is clinical suspicion that patients will require adjuvant radiation or have clinical factors such as a smoking or alcohol-use history, volume requirements may be even greater to maintain adequate parotid volume for aesthetic purposes.

The Great Gut Mimicker: A case report of MIS-C and appendicitis clinical presentation overlap in a teenage patient.

BACKGROUND: Abdominal pain and other gastrointestinal symptoms are common presenting features of multisystem inflammatory syndrome in children (MIS-C) and can overlap with infectious or inflammatory abdominal conditions, making accurate diagnosis challenging. CASE PRESENTATION: We describe the case of a 16-year-old female who presented with clinical symptoms suggestive of appendicitis and an abdominal computed tomography (CT) that revealed features concerning for appendicitis. After laparoscopic appendectomy, histopathology of the appendix demonstrated only mild serosal inflammation and was not consistent with acute appendicitis. Her overall clinical presentation was felt to be consistent with MIS-C and she subsequently improved with immunomodulatory and steroid treatment. CONCLUSIONS: We note that MIS-C can mimic acute appendicitis. This case highlights MIS-C as a cause of abdominal imaging with features concerning for appendicitis, and MIS-C should be considered in the differential for a patient with appendicitis-like symptoms and a positive COVID-19 IgG. Lab criteria, specifically low-normal white blood cell count and thrombocytopenia, appears to be of high relevance in differing MIS-C from acute appendicitis, even when appendix radiologically is dilated.

Tourniquet use and factors associated with hematoma formation in free tissue transfer.

PURPOSE: Our objective was to understand which variables are associated with hematoma formation at both the donor and recipient sites in head and neck free tissue transfer and if hematoma rates are affected by tourniquet use. METHODS: Patients were identified who underwent free tissue transfer at three institutions, specifically either a radial forearm free flap (RFFF) or a fibula free flap (FFF), between 2007 and 2017. Variables including use of tourniquet, anticoagulation, treatment factors, demographics, and post-operative factors were examined to see if they influenced hematoma formation at either the free tissue donor or recipient site. RESULTS: 1410 patients at three institutions were included in the analysis. There were 692 (49.1%) RFFF and 718 (50.9%) FFF. Tourniquets were used in 764 (54.1%) cases. There were 121 (8.5%) hematomas. Heparin drips (p < .001) and DVT prophylaxis (p = .03) were significantly associated with hematoma formation (OR 95% CI 12.23 (4.98-30.07), 3.46 (1.15-10.44) respectively) on multivariable analysis. CONCLUSIONS: Heparin Drips and DVT prophylaxis significantly increased hematoma rates in free flap patients while tourniquets did not affect rates of hematoma.

Factors associated with skin graft take in fibula and radial forearm free flap donor sites.

LEARNING OBJECTIVES: Identify factors associated with skin graft take in fibula free flaps (FFF) and radial forearm free flaps (RFFF) donor sites. STUDY OBJECTIVES: To determine which factors are associated with decreased skin graft take at the donor site in FFF and RFFF in head and neck patients. DESIGN: Retrospective Chart Review Case Series. SETTING: Multicenter Tertiary Care. METHODS: A multicenter retrospective review was performed at three institutions identifying patients who underwent free tissue transfer, specifically either FFF or RFFF, between 2007 and 2017. Patient demographics, medical history, and social history were examined including age, gender, BMI, smoking status, diabetes and preoperative anticoagulation use. Preoperative, intraoperative data, and postoperative data were also examined including tourniquet use, type of flap, area of skin graft, if the skin graft had a donor site or if it was taken from the flap, wound NPWT use, cast use, use of physical therapy, DVT prophylaxis, limb ischemia, heparin drip, and postoperative aspirin use. Statistical analysis was used to determine which factors were significantly associated with skin graft take. RESULTS: 1415 patients underwent a forearm or fibula flap and 938 patients underwent split-thickness skin graft. Of these, 592 patients had sufficient information and were included in the final analysis. There were 371 males and 220 females. The average age was 55.7. Complete skin graft take was seen in 480 patients (81.1%). On univariate analysis, patients with diabetes (p = .003), type of flap (fibula p < .001), skin graft area (p = .006), tourniquet use (p = .003), DVT prophylaxis (p = .008) and casting (p = .003) were significantly associated with decreased skin graft take rate. In a multivariate analysis, diabetes (OR 2.17 (95%CI 1.16-3.98)), fibula flaps (OR 2.86 (95%CI 1.79-4.76)), an increase in skin graft area (OR 1.01 (95%CI 1.01-1.01)), post-operative aspirin (OR 2.63 (95%CI 1.15-5.88), and casting (OR 2.94 (95%CI 1.22-7.14)) were associated with poor rates of skin graft take. CONCLUSION: Several factors affect skin graft take rate and should be considered when performing a skin graft for a donor site defect.

Management of Large Facial Defects.

There is considerable variation in the surgical management of patients with large facial defects after excision of skin malignancy. The surrounding facial subunits as well as local, regional, and distant soft-tissue flaps can be considered in more complicated facial defects. We place an emphasis on the versatility of adjacent tissue advancement and transposition flaps in the treatment of these defects. We also focus on the secondary reconstructive efforts necessary to achieve the best functional and aesthetic outcomes for patients.

Kinetic characterization of the inhibition of protein tyrosine phosphatase-1B by Vanadyl (VO2+) chelates.

Protein tyrosine phosphatases (PTPases) are a prominent focus of drug design studies because of their roles in homeostasis and disorders of metabolism. These studies have met with little success because (1) virtually all inhibitors hitherto exhibit only competitive behavior and (2) a consensus sequence H/V-C-X5-R-S/T characterizes the active sites of PTPases, leading to low specificity of active site directed inhibitors. With protein tyrosine phosphatase-1B (PTP1B) identifed as the target enzyme of the vanadyl (VO2+) chelate bis(acetylacetonato)oxidovanadium(IV) [VO(acac)2] in 3T3-L1 adipocytes [Ou et al. J Biol Inorg Chem 10: 874-886, 2005], we compared the inhibition of PTP1B by VO(acac)2 with other VO2+-chelates, namely, bis(2-ethyl-maltolato)oxidovanadium(IV) [VO(Et-malto)2] and bis(3-hydroxy-2-methyl-4(1H)pyridinonato)oxidovanadium(IV) [VO(mpp)2] under steady-state conditions, using the soluble portion of the recombinant human enzyme (residues 1-321). Our results differed from those of previous investigations because we compared inhibition in the presence of the nonspecific substrate p-nitrophenylphosphate and the phosphotyrosine-containing undecapeptide DADEpYLIPQQG mimicking residues 988-998 of the epidermal growth factor receptor, a relevant, natural substrate. While VO(Et-malto)2 acts only as a noncompetitive inhibitor in the presence of either subtrate, VO(acac)2 exhibits classical uncompetitive inhibition in the presence of DADEpYLIPQQG but only apparent competitive inhibition with p-nitrophenylphosphate as substrate. Because uncompetitive inhibitors are more potent pharmacologically than competitive inhibitors, structural characterization of the site of uncompetitive binding of VO(acac)2 may provide a new direction for design of inhibitors for therapeutic purposes. Our results suggest also that the true behavior of other inhibitors may have been masked when assayed with only p-nitrophenylphosphate as substrate.

Parathyroidectomy for tertiary hyperparathyroidism: A systematic review.

OBJECTIVE: Analyze the efficacy and indications for parathyroidectomy as an intervention for tertiary hyperparathyroidism. DATA SOURCES: PubMed, MEDLINE, and Cochrane Library databases. REVIEW METHODS: A systematic literature search was performed using the. Original research articles in English were retrieved using the search terms ("tertiary hyperparathyroidism" OR "3HPT") AND "parathyroidectomy". Articles were analyzed in regards to their surgical indications, operative endpoints, comparison between different surgical interventions, characterization of disease recurrence rates, and evaluation of alternative medical management. RESULTS: Thirty studies met the criteria for inclusion. Among the studies that report indications for parathyroidectomy, persistent hypercalcemia as well as clinical manifestations of hypercalcemia despite medical therapy predicted which patients would eventually need surgical intervention. The majority of studies comparing the extent of parathyroidectomy recommended a more focused approach to parathyroidectomy when warranted. All studies found that parathyroidectomy was an effective treatment for 3HPT. Three studies discussed alternative conservative approaches. CONCLUSION: Interestingly, hyperparathyroidism alone is not an indication for surgery without other findings; rather, symptomatic hypercalcemia appears to be the main indication. Most studies recommend limited or subtotal parathyroidectomy for 3HPT. The operative endpoint of surgery is not necessarily a return of PTH to normal, but a >50% drop in PTH level even if PTH remains above normal. Additionally, "success" or "cure" is defined as normal calcium levels regardless of whether or not PTH is elevated. It appears the goal of surgery for 3HPT is not a normal PTH value, but a normal calcium level at least six months postoperatively.

Microfluidic serial dilution ladder.

Serial dilution is a fundamental procedure that is common to a large number of laboratory protocols. Automation of serial dilution is thus a valuable component for lab-on-a-chip systems. While a handful of different microfluidic strategies for serial dilution have been reported, approaches based on continuous flow mixing inherently consume larger amounts of sample volume and chip real estate. We employ valve-driven circulatory mixing to address these issues and also introduce a novel device structure to store each stage of the dilution process. The dilution strategy is based on sequentially mixing the rungs of a ladder structure. We demonstrate a 7-stage series of 1 : 1 dilutions with R(2) equal to 0.995 in an active device area of 1 cm(2).

Pregnancy outcomes and iron status in ß-thalassemia major and intermedia: a systematic review and meta-analysis.

ABSTRACT: Advancements in orally bioavailable iron chelators and MRI methods have improved life expectancy and reproductive potential in thalassemia major (TM) and thalassemia intermedia (TI). Pregnancy is associated with adverse maternal and neonatal outcomes, frequency of which has not been well delineated. This systematic review aims to provide risk estimates of maternal and fetal outcomes in TM and TI and explore pregnancy's impact on iron homeostasis. Fifteen studies (429 participants, 684 pregnancies) were included. Meta-analysis revealed a higher thrombosis risk in TI (3.7%) compared to TM (0.92%), unchanged from prepregnancy. Heart failure risks in the earlier years appeared similar (TM 1.6% vs TI 1.1%), and maternal mortality in TM was 3.7%, but with current management, these risks are rare. Gestational diabetes and pre-eclampsia occurred in 3.9% and 11.3% of TM pregnancies, respectively. Caesarean section rates were 83.9% in TM and 67% in TI. No significant difference in stillbirth, small for gestational age neonates, or preterm birth incidence between TM and TI was observed. In TM pregnancies, red cell requirements significantly increased (from 102 to 139 ml/kg/year, P = 0.001), and 70% of TI pregnancies required blood transfusions. As expected, increased transfusion alongside chelation cessation led to a significant increase in serum ferritin during pregnancy (TM by 1005 ng/mL; TI by 332 ng/mL, P < 0.0001). Deterioration in iron status was further reflected by an increase in liver iron concentration (from 4.6 to 11.9 mg/g dry weight, P < 0.0001), and myocardial T2-star (T2∗) magnetic resonance imaging decreased (from 36.2 ± 2.5 ms to 31.1 ms) during pregnancy. These findings emphasize the elevated maternal risk of iron-related cardiomyopathy during pregnancy and labor, stressing the importance of cardiac monitoring and postpartum chelation therapy resumption.