Artificial neural network prediction of post-thyroidectomy outcome.

OBJECTIVES: The goal of this study was to develop a deep neural network (DNN) for predicting surgical/medical complications and unplanned reoperations following thyroidectomy. DESIGN, SETTING, AND PARTICIPANTS: The 2005-2017 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was queried to extract patients who underwent thyroidectomy. A DNN consisting of 10 layers was developed with an 80:20 breakdown for training and testing. MAIN OUTCOME MEASURES: Three primary outcomes of interest, including occurrence of surgical complications, medical complications, and unplanned reoperation were predicted. RESULTS: Of the 21 550 patients who underwent thyroidectomy, medical complications, surgical complications and reoperation occurred in 1723 (8.0%), 943 (4.38%) and 2448 (11.36%) patients, respectively. The DNN performed with an area under the curve of receiver operating characteristics of .783 (medical complications), .709 (surgical complications) and .703 (reoperations). Accuracy, specificity and negative predictive values of the model for all outcome variables ranged 78.2%-97.2%, while sensitivity and positive predictive values ranged 11.6%-62.5%. Variables with high permutation importance included sex, inpatient versus outpatient and American Society of Anesthesiologists class. CONCLUSIONS: We predicted surgical/medical complications and unplanned reoperation following thyroidectomy via development of a well-performing ML algorithm. We have also developed a web-based application available on mobile devices to demonstrate the predictive capacity of our models in real time.

Impact of esthesioneuroblastoma treatment delays on overall patient survival.

OBJECTIVES: To characterize clinical factors associated with esthesioneuroblastoma treatment delays and determine the impact of these delays on overall survival. STUDY DESIGN: Retrospective database analysis. METHODS: The 2004-2016 National Cancer Database was queried for patients with esthesioneuroblastoma managed by primary surgery and adjuvant radiation. Durations of diagnosis-to-treatment initiation (DTI), diagnosis-to-treatment end (DTE), surgery-to-RT initiation (SRT), radiotherapy treatment (RTD), and total treatment package (TTP) were analyzed. The cohort was split into two groups for each delay interval using the median time as the threshold. RESULTS: A total of 814 patients (39.6% female, 88.5% white) with mean ± SD age of 52.6 ± 15.1 years who underwent both esthesioneuroblastoma surgery and adjuvant radiotherapy were queried. Median DTI, DTE, SRT, RTD, and TTP were 34, 140, 55, 45, and 101 days, respectively. A significant association was identified between increased regional radiation dose above 66 Gy and decreased DTI (OR = 0.54, 95% CI 0.35-0.83, p = 0.01) and increased RTD (OR = 3.94, 95% CI 2.36-6.58, p < 0.001) durations. Chemotherapy administration was linked with decreased SRT (OR = 0.64, 95% CI 0.47-0.89, p = 0.01) and TTP (OR = 0.59, 95% CI 0.43-0.82, p = 0.001) durations. Cox proportional-hazards analysis revealed that increased RTD was associated with decreased survival (HR = 1.80, 95% CI 1.26-2.57, p < 0.005), independent of age, sex, race, regional radiation dose, facility volume, facility type, insurance status, modified Kadish stage, chemotherapy status, Charlson-Deyo comorbidity index, and surgical margins. CONCLUSIONS: Delays during, and prolongation of radiotherapy for esthesioneuroblastoma appears to be associated with decreased survival. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:764-772, 2023.

Inflammation and infarction of adipose tissue: implications in bariatric surgery.

Fat necrosis occurs more frequently in patients who have obesity and diabetes mellitus and is linked to worsening of diabetes. Little evidence is available about surgical complications that are related to inflammation and necrosis of adipose tissue. We report two cases of young women with diabetes who underwent bariatric surgery and had complications resulting from extensive inflammation and necrosis of adipose tissue. The first patient was diagnosed with omental infarction, which is a type of fat necrosis that is rarely associated with obesity and bariatric surgery. The second patient had an intraoperative finding of mesenteric panniculitis, which resulted in an intra-operative change in the choice of bariatric surgery to do a sleeve gastrectomy instead of a gastric bypass. Surgeons who perform surgery on bariatric patients must be aware of complications related to excessive amount of adipose tissue.

Giant-cell tumour of the tendon sheath in the foot and ankle.

Giant-cell tumour of the tendon sheath (GCT-TS) is a benign solitary tumour which usually arises in the limbs. It occurs most often in the hand where local recurrence after excision has been reported in up to 45% of cases. It is less common in the foot where the biological behaviour and risk of local recurrence have not been defined. We have studied 17 cases of GCT-TS of the foot and ankle in which treatment was by excision. Fifteen presented as a solitary, painless, slow-growing soft-tissue swelling. One lesion was associated with sensory deficit of a digital nerve and one with pain on walking. Thirteen cases originated from the periarticular tendon-sheath complex of the small joints of the toes and four from the capsule or long tendons of the ankle. A correct preoperative diagnosis was made in only three cases. MRI proved to be the most useful preoperative investigation as GCT-TS has a characteristic appearance which allows planned local excision to be carried out. None of the patients with histologically confirmed GCT-TS required further surgery. There was no local recurrence in 15 patients who were available for follow-up at a mean of 85 months.

Coding errors: a comparative analysis of hospital and prospectively collected departmental data.

OBJECTIVES: To assess the accuracy of a hospital coding database at a busy tertiary referral urological unit. METHODS: Prospectively collected departmental coding data for all urological patients attending the Churchill Hospital, Oxford between 1 May 1999 and 30 April 2000 were compared with the coding data entered by hospital coding clerks on the Oxford Radcliffe NHS Trust database. RESULTS: There were significant discrepancies between the number of patients on the hospital and the departmental database (639 vs 1109). There were gross procedural coding errors in 74 cases. CONCLUSION: Hospital-coded data in this study were incomplete and inaccurate. This has important implications when considering the validity of hospital-trust databases when used as a source for medical research, clinical audit and as a representation of a consultants' clinical workload.

Posterior cranial fossa venous extradural haematoma: an uncommon form of intracranial injury.

Extradural haematomas are commonly associated with direct trauma to the temporal bones of the cranium resulting in damage to the middle meningeal artery or its branches. A case is presented of an occipital skull fracture with venous sinus bleeding that resulted in a posterior cranial fossa extradural haematoma. Bleeding in this area, if unrecognised, may lead rapidly to respiratory arrest secondary to brainstem compression. The presence of significant trauma to the occiput should alert the attending clinician to the possibility of this uncommon but potentially fatal condition.

Assessment of the role of GM-CSF in the cellular transformation and the development of erosive lesions around orthopaedic implants.

Granulocyte-macrophage colony stimulating factor (GM-CSF) is a hematopoietic growth factor with a regulatory effect on the transformation of immature macrophages into multinucleated giant cells (MNGC) that exhibit phenotypic and functional characteristics of osteoclasts (OC). The authors analyzed the bone implant interface membranes harvested from 15 patients with failed total joint replacements for the production and tissue distribution of GM-CSF and interleukin-1 (IL-1). Immunohistology and liquid culture were employed to assess the contribution of these factors in the recruitment of macrophages and the development of bone resorbing MNGC at these sites. This process has been implicated in osteoclastic bone resorption, bone, and bone marrow necrosis adjacent to orthopaedic implants. Histologic assessment of the interface indicated the presence of granuloma and a variable number of MNGC in 11 cases. Four cases showed sites of intramembranous formation of osteoid and mineralized bone that was accompanied by normal bone marrow in two cases. Granulocyte-macrophage colony stimulating factor was expressed by a distinct subset of phagocytic macrophages in the lining layer on the implant side. interleukin-1-positive cells outnumbered those stained for GM-CSF. Stimulation of cultured cells with prosthetic metal particulate material showed marked similarity in the expression of these cytokines to cultures treated with lipopolysaccharide (LPS) or phytohemagglutinin (PHA). The induction of GM-CSF production in the lining layer where small MNGC develop indicates that these cells differentiate locally following the phagocytosis of particulate wear debris. In conclusion, GM-CSF promotes the proliferation and early stages of fusion and development of MNGC responsible for osteolysis at these sites. These results also highlight the capacity of the interface to display both osteogenic and inflammatory characteristics. Collectively, the findings suggest that the local bone marrow could participate in the development of the interface as a source of myeloid cells in addition to the capacity of marrow stroma to generate various osteogenic cells essential for the ingrowth of bone into prosthetic implants.

Laboratory simulations of PH3 photolysis in the atmospheres of Jupiter and Saturn.

Photolysis of NH3-PH3 mixtures (11 Torr) at 175 degrees K resulted in the same initial rate of P2H4 formation as when the 11 Torr of pure PH3 was photolyzed. A higher yield of P2H4 is obtained at 175 degrees K than at 298 degrees K because some of the P2H4 condenses on the cell wall at 175 degrees K and is not subject to further reaction. Some reaction of P2H4 is taking place as observed by the decrease in its yield and on the formation of red phosphorus on extended photolysis of PH3 at 175 degrees K. No NH2PH2 or (PN)x were detected as photoproducts as indicated by the absence of change in the UV spectral properties of the P2H4 and red phosphorus fraction, respectively, when HN3 is present. Although the pathway for PH3 decomposition is changed, the outcome of the photochemical process is essentially the same in the absence or presence of NH3. The formation of P2H4 and red phosphorus was not inhibited by small amounts of C2H4 and C2H2, so the low levels of hydrocarbons on Jupiter and Saturn will not have a significant effect on the course of PH3 photolysis. The ratio of products of PH3 photolysis are only slightly affected by the wavelength of light used. Use of a xenon lamp, with a continuous emission in the ultraviolet where P2H4 absorbs, results in only a modest decrease in the yield of P2H4 and a modest increase in the rate of formation of red phosphorus as compared to the rates observed with a 206.2-nm light source. The quantum yield for P2H4 formation is pressure independent in the 0.5-11 Torr range. This quantum yield is not affected by lowering the temperature to 157 degrees K or by the addition of 100 Torr of H2. It is concluded that photolysis of PH3 to P2H4 and the subsequent conversion of P2H4 to red phosphorus are likely processes on Jupiter and Saturn and that particles of P2H4 condense in the atmospheres of these planets. The conversion of some of the P2H4 to red phosphorus may take place on Jupiter.

Mechanism of phosphine photolysis. Application to Jovian atmospheric photochemistry.

PH3 is photolyzed to H2 and P2H4 and the P2H4 in turn is converted to red phosphorus. The initial quantum yield of H2 formation was redetermined and found to be 0.93 +/- 0.07. Red phosphorus was identified by its chemical properties and the absence of P-H stretching bands in its infrared spectrum. The reaction pathway was not changed by lowering the PH3 partial pressure from 90 to 11 torr or by performing the photolysis in a 70-fold excess of H2. The initial quantum yields at 11 torr of PH3 are phi P2H4 = 0.04 +/- 0.02 and phi H2 = 0.74 +/- 0.08. The initial rate of P2H4 formation was not affected by lowering the PH3 temperature to 227 or 157 K. The yield was greater at 157 K because the P2H4 condensed and was protected from further destruction. The initial quantum yields for the formation of P2H4 and H2 in PH3-NH3 mixtures were comparable to those observed for PH3 alone. Photolysis of mixtures in which NH3 was absorbing 90% of the light resulted in the rapid formation of P2H4. No N2 was formed when PH3-NH3 mixtures were photolyzed, suggesting that the destruction of NH3 is quenched by PH3. The application of these findings to Jovian atmospheric chemistry is discussed.