Intraoperative Regional Cerebral Oxygenation During Pediatric Thoracoscopic Surgery: A Systematic Review

Background: Ventilating a pediatric patient during thoracoscopy is challenging. Few studies have highlighted the impact of capnothorax in children by measuring regional cerebral oxygen saturation (rcSO2) with near infrared spectroscopy. In this systematic review, we aimed to summarize the data from relevant studies and assess whether thoracoscopy in children is associated with intraoperative pathological cerebral desaturation. Methods: The authors systematically searched four databases for relevant studies on the measurement of rcSO2 during pediatric thoracoscopic procedures. The primary outcome was the proportion of patients with pathological desaturation, that is, >20% decline in the intraoperative rcSO2. Risk of bias among the included studies was estimated using the Newcastle-Ottawa scale. Results: The systematic search resulted in 776 articles, of which 7 studies were included in the analysis. In total, 88 patients (99 procedures) with an age ranging from 0 days to 8.1 years were included. Of these, 43 (49%) patients were neonates. The included cohort had esophageal atresia and tracheoesophageal fistula (n = 26), long-gap esophageal atresia (n = 5), congenital diaphragmatic hernia (n = 14), and congenital pulmonary airway malformations and other conditions needing lung resection (n = 43). Of the total 99 procedures, pathological desaturation was noticed in 13 (13.1%, 95% confidence interval 7.2-21.4) of them. Upon quality assessment, most of the studies were weaker in the selection and comparability domains. Conclusion: In this review, pathological cerebral desaturation was noticed in 13.1% of the pediatric thoracoscopic procedures. However, due to limited methodological quality of the included studies, further randomized multicentric studies comparing rcSO2 in open versus thoracoscopic surgeries are needed to derive definitive conclusions.

Plasma GDNF levels in spinal dysraphism and its relation with neurological impairment in children: A point of care study

AIMS

GDNF plays a crucial role in the stimulation of recovery, neuroplasticity and synaptic reorganization after spinal cord injury providing neuroprotection and neuroregeneration. Plasma GDNF levels are upregulated in cases of spina bifida owing to the intrauterine damage of the exposed spinal cord. Our aim was to compare the plasma GDNF levels in patients of spina bifida with non-spina bifida cases and assess the correlation with neurological impairment at one year of follow up.

METHODS

Single centre prospective analysis of cases of spina bifida from 2020 to 2022 at presentation and after one year of follow up post-surgery. Cases with hernia and hydrocele without any other disorders were recruited into the control group. Plasma GDNF levels were assessed with immunoassay kits and compared with neurological involvement.

RESULTS

85 cases were included in the study. GDNF levels were elevated in cases compared to controls (mean 6.62 vs 1.76) with significant p value (<0.01). Same was observed for open and closed defects (mean 7.63 vs 4.86: p < 0.01). At follow up of 52 cases post-surgery cases with neurogenic bladder with abnormal urodynamic studies, sphincter involvement and motor impairment had significantly elevated baseline levels of GDNF compared with those who did not have this neurological impairment (p < 0.01).

DISCUSSION

The neurotrophic factor up-regulation can reflect an endogenous attempt at neuroprotection against the biochemical and molecular cascades triggered by the spinal cord damage. This upregulation can be represented as important biochemical markers of severe spinal cord damage and can be associated with severity of spine injury in MMC patients. Our results are in keeping with these findings, that, there were increased levels of plasma GDNF levels in cases of spinal dysraphism compared to control population. Also, the type of lesion reflecting the severity whether a closed or an open dysraphism, showed significant difference in levels between them suggesting, yet again, more damage in open defect as expected. The levels were higher with involvement of bladder, sphincter and lower limb power.

CONCLUSION

There is significant elevation of plasma GDNF levels in cases of spina bifida and this elevation is proportional to the degree of spinal damage and hence the neurological impairment. GDNF levels are a good predictor for assessing the severity of the lesion and thus the outcome in these cases. Additional prospective and long-term studies with a larger cohort are needed for a better understanding of neurotrophin pattern modulation in MMC.

Role of Magnetic Compression Anastomosis in Long-Gap Esophageal Atresia: A Systematic Review

Background: Magnetic compression anastomosis (MCA) is an alternative technique for patients with long-gap esophageal atresia (EA). It allows for preservation of the native esophagus. We aimed to systematically summarize the current literature on MCA in EA. Methods: Studies where neonates with EA were treated with MCA devices were included, while studies on esophageal stenosis were excluded. All clinical studies, including comparative studies, case series, and case reports, were eligible for inclusion. Methodological quality assessment was performed using a validated tool. Results: Twelve studies with a total of 42 patients were included in this review. There was a wide variation among these studies with regard to the time of initiation of MCA (1 day to 7 months), procedure time (13-320 minutes), and magnet characteristics (strength, size, and shape of the magnets used). The time to achieve anastomosis ranged from 1 to 12 days. Stricture at the anastomotic site was reported in almost all the patients, which required multiple endoscopic dilatations (median no. of dilatations/patient = 9.8). Stent placement for refractory stricture was required in 9 (21%) patients, and surgery for stricture was required in 6 (14%) patients. Long-term outcomes included esophageal dysmotility (n = 3) and recurrent pulmonary infections (n = 3) were reported in only four studies. Conclusion: As per the findings of this review, neonates with long-gap EA undergoing MCA would invariably require multiple sittings of endoscopic dilatations (median no. of dilatations/patient = 9.8). Also, there is a wide variation among the included studies in terms of the procedure of MCA. Future studies with a standardized procedure for achieving MCA are needed to determine additional outcomes in this fragile patient population.

PIC cystography in occult vesicoureteral reflux: A systematic review highlighting its utility in children with recurrent urinary tract infections and normal VCUG

BACKGROUND

Vesicoureteral reflux (VUR) affects 1-2% of children, predisposing them to pyelonephritis, renal scarring, and reflux nephropathy. Treatment aims to prevent febrile urinary tract infections (f-UTI) and long-term sequelae. While guidelines differ, the current consensus proposes individual risk-stratification and subsequent management strategies. Here, we systematically analyzed the current literature on Positional Instillation of Contrast Cystography (PIC) for individualized diagnostics in patients with recurrent f-UTIs.

OBJECTIVE

We present a comprehensive qualitative and quantitative synthesis. Outcomes were: 1. the ability of PIC to predict VUR in patients with negative voiding cystographies (VCUG), 2. the ability of PIC to predict occult contralateral VUR, 3. the correlation of occult VUR in PIC with dimercaptosuccinic acid (DMSA) scan findings, and 4. the incidence of postoperative f-UTI in children treated for occult VUR picked up on PIC.

STUDY DESIGN

We conducted a systematic review following the PRISMA guidelines, applying the following inclusion criteria: Children with occult VUR in PIC with negative VCUG.

RESULTS

We included nine studies with 496 symptomatic patients with a mean age of 6.8 years, published between 2003 and 2021. PIC detected VUR in 73% of patients. Out of them, 81% had low-grade and 19% high-grade VUR. Occult contralateral VUR was present in 41% children. The presence of renal scars on DMSA scan was 1.39 times more likely with occult VUR on PIC. 85% of patients did not experience recurrent f-UTIs after PIC and subsequent treatment.

DISCUSSION

PIC can detect occult VUR in patients with recurrent f-UTIs in whom VCUG is negative. However, we recommend a cautious approach in the use of PIC in clinical practice until further prospective studies confirm the validity of our outcome measures.

CONCLUSION

Identification, risk stratification, and prompt action are central in managing VUR. PIC can be helpful in identifying VUR in patients with recurrent f-UTI.

Pleiotrophin-Neuregulin1 promote axon regeneration and sorting in conduit repair of critical nerve gap injuries

Significant challenges remain in the treatment of critical nerve gap injuries using artificial nerve conduits. We previously reported successful axon regeneration across a 40 mm nerve gap using a biosynthetic nerve implant (BNI) with multi-luminal synergistic growth factor release. However, axon sorting, remyelination, and functional recovery were limited. Neuregulin1 (NRG1) plays a significant role in regulating the proliferation and differentiation of Schwann cells (SCs) during development and after injury. We hypothesize that the release of NRG1 type III combined with pleiotrophin (PTN) in the BNI will enhance axon growth, remyelination, and function of regenerated nerves across a critical gap. A rabbit 40 mm peroneal gap injury model was used to investigate the therapeutic efficacy of BNIs containing either NRG1, PTN, or PTN+NRG1 growth factor release. We found that NRG1 treatment doubled the number of regenerated axons (1276±895) compared to empty controls (633±666) and PTN tripled this number (2270±989). NRG1 also significantly increased the number of SOX10+ Schwann cells in mid-conduit (20.42%±11.78%) and reduced the number of abnormal Remak axon bundles. The combination of PTN+NRG1 increased axon diameter (1.70±1.06) vs control (1.21±0.77) (p<0.01), with 15.35% of axons above 3 μm, comparable to autograft. However, the total number of remyelinated axons was not increased by the added NRG1 release, which correlated with absence of axonal NRG1 type III expression in the regenerated axons. Electrophysiological evaluation showed higher muscle force recruitment (23.8±16.0 mN vs 17.4±1.4 mN) and maximum evoked compound motor action potential (353 μV vs 37 μV) in PTN-NRG1 group versus control, which correlated with the improvement in the toe spread recovery observed in PTN-NRG1 treated animals (0.64±0.02) vs control (0.50±0.01). These results revealed the need of a combination of pro-regenerative and remyelinating growth factor combination therapy for the repair of critical nerve gaps.

Bibliometric Analysis and Visualization of the Extrahepatic Portal Venous Obstruction Publication Landscape

Introduction

A scientometric analysis was conducted to characterize the global research publications in extrahepatic portal venous obstruction (EHPVO), and state-of-the-art visualization graphics were generated to provide insight into specific bibliometric variables.

Materials and Methods

The Web of Science database was accessed for research productivity and bibliometric variables of countries, institutions, authors, journals, and content analysis of top-20 cited documents were performed. Collaborative networks and co-occurrence of keywords map were generated using VOSviewer software.

Results

Two hundred and sixteen records were retrieved with an annual growth rate of 2.53%. India is the leading country in productivity (n = 4339), followed by the USA and China. Post Graduate Institute of Medical Education and Research, Chandigarh, was the top productive institute. Sarin SK was the most prolific author, having the highest citations received and h-index. The hotspot topics were "portal hypertension," "cirrhosis," "children," "biliopathy/cholangiopathy," "liver fibrosis," and "liver transplantation" as per keyword co-occurrence networking. J Gastroenterol Hepatol had the most publications of EHPVO research as well the h-index. Regarding collaborative network mapping, the USA and Primignani M were the significant nodes among country and author, respectively.

Conclusion

EHPVO research publication volume is low but is gradually progressing with dominant contributions from Indian institutes and authors. Most highly cited articles are of low level of evidence, and multi-institutional collaborative research can be the way forward.

Establishing proof of concept for utility of Trueprep®-extracted DNA in line-probe assay testing

BACKGROUND AND OBJECTIVES: With an increased demand for rapid, diagnostic tools for TB and drug resistance detection, Truenat® MTB-RIF assay has proven to be a rapid point of care molecular test. The present study aimed to establish a proof of concept of using Trueprep-extracted DNA for line-probe assay (LPA) testing.METHODS: A total of 150 sputum samples (MTB-positive at Truenat sites) were divided into two aliquots. One aliquot was used for DNA extraction using the Trueprep device and MTB testing. The second aliquot of the sample was subjected to GenoLyse® DNA extraction. DNA from both the Trueprep and GenoLyse methods was subjected to first-line (FL) and second-line (SL) LPA testing.RESULTS: Of 139 Trueprep-extracted DNA, respectively 135 (97%) and 105 (75%) had interpretable results by FL and SL-LPA testing. Of 128 GenoLyse-extracted DNA, all 128 (100%) had interpretable FL-LPA results and 114 (89%) had interpretable SL-LPA results.CONCLUSION: The results obtained in this study indicate that Trueprep-extracted DNA can be used in obtaining valid LPA results. However, the study needs to be conducted on a larger sample size before our recommendations can be used for policy-making decisions.

Defining the Indications of PATIO Technique for Urethrocutaneous Fistula Repair

Introduction

Despite the advancements in technique and technology, urethrocutaneous fistula (UCF) formation continues to be the most common complication after hypospadias repair.

Objective

The objective of the current synthesis is to define the indications of PATIO technique for UCF repair.

Materials and Methods

The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Scopus, Ovid, Embase, Web of Science, and Google Scholar were interrogated for studies presenting primary data upon UCF repair by the PATIO technique. Data analysis was performed on MedCalc and R software.

Results

Eighteen studies were identified relevant to the current context: inversion of UCF tract has been described in 13 and ligation in 5. There were 2 duplications (abstract and manuscript). The overall success for PATIO is 88.2% (314/356). The success rate was variable between classic PATIO (inversion at 87.2%), ligation-inversion at 86.9%, and ligation alone at 88.9%. The success rate was not improvised upon by supplementing inversion of UCF tract with ligation (p = 0.957) or addition of a waterproofing layer (p = 0.622). PATIO has been used for single or multiple UCFs post hypospadias repair, genital piercing, and genitoplasty in cis- or transgender population for UCF up to 5 mm in size. The success rates were best for UCF <2 mm and worst for those approaching 5 mm. The results were, however, unaffected by the location of UCF along the penile shaft. Besides, the use of urethral catheter is optional and may be eliminated with shorter hospitalization.

Conclusions

PATIO repair may be considered for repair of UCFs (a) with diverse etiologies, (b) located anywhere along the penile shaft included coronal UCF, (c) preferably <4 mm in size, (d) single or multiple in number; multiple PATIOs may be done in the same setting, (e) in patients unwilling for prolonged hospitalization, (f) in patients unwilling for a urethral catheter, and (g) in hypospadias cripples wherein mobilization of distant tissues such as tunica vaginalis flap or a buccal mucosal graft may be required for supplementing the UCF repair.

Utility of Ischemia-Modified Albumin as a Biomarker for Acute Appendicitis: A Systematic Review and Meta-Analysis

BACKGROUND

Acute appendicitis is a frequently encountered surgical emergency. Despite several scoring systems, the possibility of delayed diagnosis persists. In addition, a delayed diagnosis leads to an increased risk of complicated appendicitis. Hence, there is a need to identify biological markers to help clinicians rapidly and accurately diagnose and prognosticate acute appendicitis with a high sensitivity and specificity. Although several markers have been evaluated, the pressing concern is still the low specificity of these markers. One such marker is serum ischemia-modified albumin (IMA), which can be a novel biomarker for accurately diagnosing and prognosticating acute appendicitis.

METHODS

The authors conducted a systematic search of the PubMed, EMBASE, Web of Science, and Scopus databases through February 2023 as per the PRISMA guidelines. The difference in the levels of IMA between patients with acute appendicitis vs. healthy controls, and the difference in the levels of IMA between patients with complicated vs. non-complicated acute appendicitis were taken as the outcome measures. Statistical analysis was performed using a random effects model and mean difference (MD) was calculated. The methodological quality of the studies was assessed by utilizing the Newcastle-Ottawa scale.

RESULTS

A total of six prospective comparative studies were included in the meta-analysis. The analysis revealed that the mean level of serum IMA was significantly raised in the acute appendicitis group (MD 0.21, 95% CI 0.05 to 0.37, p = 0.01). Similarly, the mean serum IMA levels were also raised in the complicated appendicitis group compared to the non-complicated appendicitis group (MD 0.05, 95% CI 0.01 to 0.10, p = 0.02). Three of the studies included were, however, of poor methodological quality.

CONCLUSIONS

Serum IMA is a viable potential marker for diagnosing and prognosticating acute appendicitis. However, due to the limited methodological quality of available studies, further prospectively designed and adequately powered studies are needed.

Knowledge and Information Resources about Child Abuse among Government and Private Dental Practitioner in Uttar Pradesh, India

Background and Aim

To evaluate knowledge, attitude, and information sources about child abuse and neglect (CAN) among dentists in Varanasi district of Uttar Pradesh state, India.

Subjects and Methods

A cross-sectional online survey was carried out of dentist working in government and private hospitals in the Varanasi district, Uttar Pradesh State, India (n = 674). The structured questionnaire was sent through electronic mail that contained the consent form, instructions for filling, and returning the questionnaire. The data obtained were systematically compiled and the Chi-square test was applied to test the association. The significance level of P ≤ 0.05 was applied.

Results

A maximum number of dental practitioners from the government (81.97%) and private sector (85.98%) were aware of the child protection law. A significant number of government and private dental practitioners were satisfied with their knowledge (p = 0.0092); however, 83.79% suggested that the continuing education programs/courses were important tool to update their knowledge. The girl child was maximum sufferer (p = 0.0056) of CAN. Only 14.08% of practitioners acted on the suspected cases, and a statistical significant relation was observed between the government and private dental practitioners for not taking any action on child abuse and neglect (p = 0.0010).

Conclusions

Data from this study may provide a useful contribution to the current limited knowledge about the familiarity of dental practitioners with child maltreatment and their skills to recognize and manage CAN cases in their practice. The majority of dental practitioners knew about the child protection law in India, but they were reluctant to report such cases due to the fear of anger from the parents and family of the child. Continuing education programs/courses were the most preferred method for increasing the knowledge regarding CAN. They should report the CAN cases to local legislators and health authorities so to prevent child abuse and neglect from ever occurring.

Preoperative and postoperative urinary NGAL levels in children with bladder exstrophy

BACKGROUND

Urinary NGAL (neutrophil gelatinase-associated lipocalin) levels have been shown to predict renal damage in various medical conditions. The present study was conducted to study the role of urinary NGAL levels in children with bladder exstrophy-epispadias complex post single-stage total reconstruction (SSTR) as markers of early renal function reduction.

METHODS

Urine samples were collected from children with bladder exstrophy before SSTR (Group A, n = 11), 5 years post SSTR (Group B, n = 40) and controls (Group C, n = 41) and stored at - 20 °C. NGAL levels were estimated using double antibody sandwich ELISA.

RESULTS

Mean NGAL levels in Groups A, B and C were 1.39, 34.24 and 2.58 ng/ml, respectively. Mean NGAL levels among Group B subjects with glomerular filtration rate (GFR) ≥ 80 ml/min/1.73 m2 body surface area (BSA) was 29.8 ng/ml, while it was 31.74 ng/ml in those with GFR < 80 ml/min. Urine samples were also evaluated 6 months post SSTR. Mean NGAL at 6 months was 6.76 ng/ml, while at 12 months it was 30.3 ng/ml, remaining > 30 ng/ml at 18 and 24 months. Dimercaptosuccinic acid (DMSA) scans did not show any scarring, and GFR on diethylenetriamine pentaacetate (DTPA) scans remained stable.

CONCLUSIONS

Increasing levels of urinary NGAL following bladder-exstrophy and epispadias complex repair suggest that NGAL detects the earliest signs of renal damage even before any deterioration is observed in DMSA and/or DTPA-GFR scans. Further studies with an adequate sample size and periodic measurement of NGAL need to be performed before any definitive conclusion can be drawn.

Mid-circuit correction of correlated phase errors using an array of spectator qubits

Scaling up invariably error-prone quantum processors is a formidable challenge. Although quantum error correction ultimately promises fault-tolerant operation, the required qubit overhead and error thresholds are daunting. In a complementary proposal, co-located, auxiliary 'spectator' qubits act as in-situ probes of noise, and enable real-time, coherent corrections of data qubit errors. We use an array of cesium spectator qubits to correct correlated phase errors on an array of rubidium data qubits. By combining in-sequence readout, data processing, and feed-forward operations, these correlated errors are suppressed within the execution of the quantum circuit. The protocol is broadly applicable to quantum information platforms, and establishes key tools for scaling neutral-atom quantum processors: mid-circuit readout of atom arrays, real-time processing and feed-forward, and coherent mid-circuit reloading of atomic qubits.

Postoperative necrotising enterocolitis following incarcerated inguinal hernia repair

The occurrence of postoperative necrotising enterocolitis (NEC) is rare. In comparison with the commonly known inciting factors for the development of NEC, surgical stress as a cause of NEC is relatively uncommon. We report a case of incarcerated inguinal hernia in a preterm infant who clinically deteriorated in the postoperative period because of NEC following herniotomy. The patient's clinical, biochemical and radiological features were suggestive of NEC, and the patient responded to the appropriate treatment based on the diagnosis. To conclude, incarcerated inguinal hernia should always be considered a causative factor for postoperative NEC.

'Waterproofing layers' for urethrocutaneous fistula repair after hypospadias surgery: evidence synthesis with systematic review and meta-analysis

OBJECTIVE

To summarize the available evidence and to quantitatively evaluate the global results of different waterproofing layers in substantiating the UCF repair.

MATERIAL AND METHODS

After defining the study protocol, the review was conducted according to the PRISMA guidelines by a team comprising experts in hypospadiology, systematic reviews and meta-analysis, epidemiology, biostatistics and data science. Studies published from 2000 onwards, reporting on the results of UCF closure after hypospadias repair were searched for on PUBMED, Embase and Google Scholar. Study quality was assessed using Joanna Briggs Checklist (JBI) critical appraisal tool. The results with different techniques were compared with the two samples independent proportions test with the help of Microsoft Excel, MedCalc software and an online calculator.

RESULTS

Seventy-three studies were shortlisted for the synthesis; the final analysis included 2886 patients (71 studies) with UCF repair failure in 539. A summary of various dimensions involved with the UCF repair has been generated including time gap after last surgery, stent-vs-no stent, supra-pubic catheterization, suture material, suturing technique, associated anomalies, complications, etc. The success rates associated with different techniques were calculated and compared: simple catheterization (100%), simple primary closure (73.2%), dartos (78.8%), double dartos flaps (81%), scrotal flaps (94.6%), tunica vaginalis (94.3%), PATIO repair (93.5%), biomaterials or dermal substitutes (92%), biocompatible adhesives (56.5%) and skin-based flaps (54.5%). Several techniques were identified as solitary publications and discussed.

CONCLUSIONS

Tunica vaginalis and scrotal flaps offer the best results after UCF closure in the synthesis. However, it is not possible to label any technique as ideal or perfect. Almost all popular waterproofing layers have depicted absolute (100%) success sometimes. There are a vast number of other factors (patient's local anatomy, surgeon's expertise and technical perspectives) which influence the final outcome.

Singlet Molecular Oxygen: from COIL Lasers to Photodynamic Cancer Therapy

Translation of experimental techniques from one scientific discipline to another is often difficult but rewarding. Knowledge gained from the new area can lead to long lasting and fruitful collaborations with concomitant development of new ideas and studies. In this Review Article, we describe how early work on the chemically pumped atomic iodine laser (COIL) led to the development of a key diagnostic for a promising cancer treatment known as photodynamic therapy (PDT). The highly metastable excited state of molecular oxygen, a¹Δ_g, also known as singlet oxygen, is the link between these disparate fields. It powers the COIL laser and is the active species that kills cancer cells during PDT. We describe the fundamentals of both COIL and PDT and trace the development path of an ultrasensitive dosimeter for singlet oxygen. The path from COIL lasers to cancer research was relatively long and required medical and engineering expertise from numerous collaborations. As we show below, the knowledge gained in the COIL research, combined with these extensive collaborations, has resulted in our being able to show a strong correlation between cancer cell death and the singlet oxygen measured during PDT treatments of mice. This progress is a key step in the eventual development of a singlet oxygen dosimeter that could be used to guide PDT treatments and improve outcomes.

Management and Outcomes of Children with Stage 4S (MS) Neuroblastoma: A Single-Center Experience from a Resource-Challenged Nation

OBJECTIVES

To demonstrate the clinical profile, management options, and outcomes of children with stage 4S neuroblastoma (NB 4S) diagnosed at a tertiary care center in a resource-challenged nation. The authors also intend to highlight the factors associated with an unfavorable prognosis in this series of patients.

METHODS

The archives for children with NB 4S, diagnosed over a 24-y period (January 1996-December 2019), were retrospectively retrieved. Data on patient characteristics, management protocols, oncologic outcomes, and overall survival (OS) were reviewed. Multivariate logistic- regression analysis was performed to identify the factors independently predicting unfavorable outcomes.

RESULTS

A total of 22 children (59% males) were included. Adrenal was the most common (82%) primary site. Liver involvement (100%), bone marrow infiltration (23%), and subcutaneous nodules (9%) were observed upon evaluation. Management involved supportive treatment (22%), chemotherapy only (41%), chemotherapy and tumor excision (28%). Ventral hernia was created in two children (9%) due to abdominal compartment syndrome (ACS). Four children died (4/22; 18%) due to ACS (n = 2) and refractory coagulopathy (n = 2). There were no recurrences and all survivors were disease-free. The 5-y OS was 81.8% with a median follow-up duration of 31 mo (range 9 mo-22 y). Age < 2 mo (p = 0.002), respiratory distress at presentation (p < 0.001), and chemotherapy nonresponsiveness (p < 0.001) were significantly associated with mortality. All three factors were independent predictors of mortality.

CONCLUSION

Children with NB 4S have a favorable outcome with 5-y OS of 81.8%. Age < 2 mo, respiratory distress at presentation, and chemotherapy nonresponsiveness are independent predictors of a poor outcome.

Isoperistaltic gastric tube: a versatile, length-gaining option for esophageal replacement in children and adolescents

Several substitutes, including gastric transposition, colonic interposition, reverse gastric tube (RGT), etc., have been described for esophageal replacement in children and adolescents. However, the search for the ideal esophageal substitute continues due to adverse events associated with these procedures. This report presents our technique for creating an isoperistaltic gastric tube (IGT). We believe that the IGT is a versatile option for esophageal replacement as it is never length-limiting, and additional length can be gained by making minor adjustments.

Laparoscopic Excision of Large Wilms Tumor in Children: A Single-Center Experience from a Resource-Challenged Nation

Background: In this study, we aim to review the outcomes of children with Wilms tumor (WT) operated through the minimally invasive surgery (MIS) approach at our center. We also intend to highlight essential surgical steps during laparoscopic excision of large WTs. Methods: This retrospective study included children with unilateral WT who had undergone resection for a period of 4 years, w.e.f. July 2013 to July 2017. Simple maneuvers such as tilting the table in different positions and use of blunt metallic cannula to lift the tumor to access the hilar vessels were used to dissect large WT. An extended lumbotomy incision was used for retrieval of tumor and lymph-node sampling. Results: Eleven patients (male:female = 7:4) of WT, all having stage III disease, had undergone laparoscopic tumor resection at our center during the study period. The median age at presentation was 36 months (range = 17 months-5 years) and the median preoperative tumor volume was 1140 (range = 936-1560) cm³. The average length of the lumbotomy incision was 6.3 (range = 5-8.2) cm. The median hospital stay was 6 (range = 5-10) days. Two children developed complications (port-site recurrence and grade III surgical site infection in one each) during the postoperative period. All cases are long-term survivors after a median follow-up of 86 (range = 56-104) months. Conclusion: This study highlights the feasibility and safety of the removal of large WT through the MIS approach. Problems due to large-sized tumors in children can be overcome by simple maneuvers. Also, adequate lymph node sampling is possible with a suitably placed extended lumbotomy incision for tumor removal.

Evaluation of the simulated aerosol optical properties over India: COALESCE model inter-comparison of three GCMs with ground and satellite observations

Within the framework of COALESCE project (Carbonaceous aerosol emissions, source apportionment, and climate impacts) initiative, spatio-temporal distribution of aerosol optical properties from three general circulation models are evaluated against aerosol data from satellite observations (MODIS and CALIPSO) and ground-based measurements (AERONET) for the period 2005-2014. The GCMs, NICAM-SPRINTARS (N-S), ECHAM6.3-HAM2.3 (E-H), CAM5.3 (CAM), input with identical emissions from the SMoG-India-v1 emission inventory over India nested in the CEDS global inventory, including all emission sectors except sea salt and soil dust. The annual mean total aerosol optical depth (AOD) averaged over the Indian land region is 0.38, 0.27, and 0.17 from the N-S, CAM, and E-H models respectively, while the annual mean value from the MODIS observational dataset is 0.43. Single scattering albedo predicted by E-H is lower compared to CAM and N-S while model predictions of Angstrom exponent are closer to MERRA2 dataset. However, the average total aerosol column burden over Indian landmass simulated by the models is very close and comparable to the reanalysis results. Statistical analysis of AOD between model and AERONET measurements at nine sites shows that the root mean square error varies from 0.1 to 0.4 and the index of agreement (average value) is ∼0.4. The aerosol emission and transport models, methodology for calculation of aerosol optical properties and their mixing states contributes to the diversity in the results from various models. The present study provides an analysis of limitations and uncertainties contributing to the differences between the simulations and observations, and the inter-model diversity.

Learning Curves in Pediatric Robot-Assisted Pyeloplasty: A Systematic Review

Background: Robot-assisted surgery demands a specific skillset of surgical knowledge, skills, and attitudes from the robotic surgeon to function as part of the robotic team and for maximal utility of the assistive surgical robot. Subsequently, the learning process of robot-assisted surgery entails new modes of learning. We sought to systematically summarize the published data on pediatric robot-assisted pyeloplasty (pRALP) to decipher the learning process by analyzing learning curves. Methods: This review followed the PRISMA guidelines. PubMed, EMBASE, Web of Science, and Scopus databases were systematically searched for ‘learning curve’ AND ‘pediatric pyeloplasty’. All studies presenting outcomes of learning curves (LC) in the context of pRALP in patients < 18 years of age were included. Studies comparing LC in pRALP versus open and/or laparoscopic pyeloplasty were also included; however, those solely focusing on LC in non-robotic approaches were excluded. The methodological quality was assessed using the Newcastle and Ottawa scale. Results: Competency was non-uniformly defined in all fifteen studies addressing learning curves in pRALP. pRALP was considered safe at all stages. Proficiency in pRALP was reached after 18 cases, while competency was estimated to demand 31 operated cases with operative duration as outcome variable. Conclusions: Pediatric RALP is safe during the learning process and ‘learning by doing’ improves efficiency. Competencies with broader implications than time must be defined for future studies.

Evaluation of 30-day morbidity and mortality of laparoscopic cholecystectomy: a multicenter prospective observational Indian Association of Gastrointestinal Endoscopic Surgeons (IAGES) Study

BACKGROUND

Laparoscopic cholecystectomy (LC) is the standard of care for benign gallstone disease. There are no robust Indian data on the 30-day morbidity and mortality of this procedure. A prospective multicentre observational study was conducted by the Indian Association of Gastro-Intestinal Endo Surgeons (IAGES) to assess the 30-day morbidity and mortality of LC in India.

MATERIALS AND METHODS

Participating surgeons were invited to submit data on all consecutive LCs for benign diseases performed between 09/12/2020 and 08/03/2021 in adults. Primary outcome measures were 30-day morbidity and mortality. Univariate and multivariate analyses were performed to identify variables significantly associated with primary outcomes.

RESULTS

A total of 293 surgeons from 125 centres submitted data on 6666 patients. Of these, 71.7% (n = 4780) were elective. A total LC was carried out in 95% (n = 6331). Laparoscopic subtotal cholecystectomy was performed in 1.9% (n = 126) and the procedure were converted to open in 1.4% of patients. Bile duct injury was seen in 0.3% (n = 20). Overall, 30-day morbidity and mortality were 11.1% (n = 743) and 0.2% (n = 14), respectively. Nature of practice, ischemic heart disease, emergency surgery, postoperative intensive care, and postoperative hospital stay were independently associated with 30-day mortality. Age, weight, body mass index, duration of symptoms, nature of the practice, history of Coronavirus Disease-2019, previous major abdominal surgery, acute cholecystitis, use of electrosurgical or ultrasonic or bipolar energy for cystic artery control; use of polymer clips for cystic duct control; conversion to open surgery, subtotal cholecystectomy, simultaneous common bile duct exploration, mucocele, gangrenous gall bladder, dense adhesions, intraoperative cholangiogram, and use of drain were independently associated with 30-day morbidity.

CONCLUSION

LC has 30-day morbidity of 11.1%, 30-day mortality of 0.2%, conversion to open rate of 1.4%, and bile duct injury rate of 0.3% in India.

Evaluation of the benefit of rivaroxaban on VOYAGER PAD primary composite of limb, heart and brain outcomes using the global rank and win ratio methods

Background/Introduction

The VOYAGER PAD trial demonstrated that rivaroxaban 2.5 mg twice daily added to background antiplatelet therapy reduced a composite of irreversible harm events of the heart limb and brain versus placebo in patients with symptomatic peripheral artery disease (PAD) after lower extremity revascularization. The primary analysis was performed as time to first event with equal weighting of components including fatal and non-fatal events.

Purpose

Traditional time to event analyses of composites generally assess outcomes with equal weights. Analyses evaluating outcomes using ranked or weighted methods may provide clinicians a mechanism to interpret results including different weighting and enable shared decision making with patients.

Methods

Exploratory analyses of the primary composite outcome were prespecified prior to trial completion/database lock. Two previously described approaches to evaluate composite outcomes by ranking or weighting were utilized. The first was the global rank method which includes ranking all components of the composite by order of clinical importance (Table 1) with a primary and alternative ranking prespecified. Each patient is assigned a rank with the worse rank for worse outcome and for patients with the same outcome, those occurring earlier assigned the worse rank. Van Elteren test for differences between groups was applied stratified by type of procedure and clopidogrel use consistent with the primary trial analysis. The second was the unmatched win ratio method according to Pocock's rule which ranked CV death higher than non-fatal events and then compared pairs of subjects, one from each treatment group for wins and losses for wins and losses as outlined in Table 1. Finkelstein and Schoenfeld statistics were utilized with confidence intervals provided from bootstrapping.

Results

A total of 6564 patients were randomized and all outcomes through the common study end date were counted. The global rank method using both the primary and alternative method yielded a statistically significant superior effect of rivaroxaban versus placebo (p-value for primary ranking 0.0158, p-value for alternative ranking 0.0155). When using the win-ratio approach, there were more wins for rivaroxaban (14.8%) than placebo (12.8%) with 72.4% of patients having no primary component events (Figure 1). The overall win ratio was 1.16 95% CI (1.03–1.30) in favor of rivaroxaban with p=0.0167.

Conclusion(s)

Rivaroxaban significantly reduces acute limb ischemia, amputation, MI, ischemic stroke or CV death in PAD after lower extremity revascularization. Exploratory analyses of this efficacy composite show consistent superiority either when considered as a ranked hierarchy of outcomes with CV death as the worst or whether considering a win-ratio approach ranking CV death as worse followed by non-fatal events. These data support the robustness of the primary trial results when considering ranking of the composite components.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Bayer

Publication landscape of Posterior urethral valve- A scientometric study

To assess the global research landscape in the field of Posterior urethral valve (PUV), a scientometric study was conducted to determine the quantity and quality of the research output and get insight into the key research areas and pattern of collaboration in the research community.

METHODS

Primary data was acquired from the Scopus® database. Various parameters like the total research productivity, citations, citations per publication, citations per year, citations per publication per year, the scientific output of countries, institutions, authors, and journals were calculated. Key research areas were inferred by examining the top-cited articles (citations >150). Collaborative maps were generated by calculating co-authorship links amongst countries and authors using VOSviewer software.

RESULTS

One thousand seven hundred fourteen results were found published from 1913 to 2019, receiving a total of 27,253 citations, authored by 5138 authors from 125 countries. The top three countries were the United States of America (USA), India, and the United Kingdom (UK). The leading institutes were the Children's Hospital Boston, USA (n = 48), All India Institute of Medical Sciences (AIIMS, Delhi), India (n = 38), and Great Ormond Street Hospital, UK (n- = 27). The journals which published the most articles on PUV were the Journal of Urology (n = 278), Journal of Pediatric Urology (n = 121), followed by Urology (n = 86). Leading authors were Glassberg, K. L and Bajpai M (n = 17, each), Canning DA & Kajbafzadeh, AM (n = 16, each), followed by Peters CA with 14 manuscripts. The top-cited documents (n = 10) received 2104 citations and were published between 1986 and 2010. The key areas of interest found were "long-term outcomes" (n = 4) and "fetal surgery" (n = 2). The most productive countries were also the most collaborative countries (the USA and UK).

CONCLUSION

In the research landscape of PUV, the USA, Children's Hospital Boston, and Glassberg, K. L, along with Bajpai, M were the top contributors in terms of the country, organization, and authors, respectively. The "Journal of Urology" and "Pediatric Nephrology" stands out in terms of bibliometric parameters considered. The hotspot topics based on the number of citations received were "long-term outcomes" and "fetal surgery" in PUV. The most productive countries were also the most collaborative countries (the USA and UK).

Are online discussion forums useful platforms for paediatric surgeons to seek advice regarding patient management? A review of the queries posted on the world federation of association of pediatric surgeons facebook group (The Pediatric Surgeon's Lounge)

BACKGROUND

Social media platforms are popular places for discussing difficult cases amongst the surgeons. Paediatric Surgeon's Lounge (PSL) is a closed Facebook group for the interaction of paediatric surgeons from different parts of the world. We aim to assess the safety and utility of the responses given by the members of the PSL group to the queries about the management of paediatric surgical cases.

METHODS

All posts on PSL between January and July 2021 were retrospectively screened to select the patient management-related queries. For each included query, all the responses were scrutinised for their utility and safety. The utility was categorised as helpful or not helpful, and the safety of these responses was categorised as safe or unsafe. A note was also made whether any unsafe response was rectified in the subsequent responses or not. The proportion of each response category was calculated.

RESULTS

Twenty-two queries with a total of 353 responses were assessed. The median (range) number of responses per query was 10 (2-45). The proportion of helpful, safe and rectified unsafe responses was 91.5% (307/353), 96.8% (342/353) and 36% (4/11), respectively.

CONCLUSIONS

PSL is a safe and helpful platform for taking advice regarding the management of paediatric surgical cases.

P10.12.A CDK12/CDK13 inhibition disrupts a transcriptional program critical for glioblastoma survival

Background

Glioblastoma multiforme (GBM) is the most prevalent and aggressive malignant tumor of the central nervous system. With a median survival of only one year, GBM patients have a particularly poor prognosis, highlighting a clear need for novel therapeutic strategies to target this disease. Transcriptional cyclin-dependent kinases (CDK), which phosphorylate key residues of RNA polymerase II (RNAPII) C-terminal domain (CTD), play a major role in sustaining aberrant transcriptional programs that are key to development and maintenance of cancer cells.

Material and Methods

We used pharmacological inhibition and genetic ablation to study effects of CDK12/CDK13 depletion on the proliferatory and migratory capacity of GBM cells and mouse xenografts. SLAM-seq, CUT&RUN and cell cycle assays were used to study the mechanistic effects of CDK12/CDK13 depletion in GBM cells.

Results

CDK12/CDK13 depletion markedly reduced the proliferatory and migratory capacity of GBM cells, as well as in vivo growth. CDK12/CDK13 inhibition potentiated existing chemotherapeutic treatments. Mechanistically, inhibition of CDK12/CDK13 leads to a genome-wide abrogation of RNAPII CTD phosphorylation, which in turn disrupts transcription and cell cycle progression in GBM cells.

Conclusion

These results provide proof-of-concept for the potential of CDK12 and CDK13 as therapeutic targets for GBM.

Search for Subsolar-Mass Binaries in the First Half of Advanced LIGO's and Advanced Virgo's Third Observing Run

We report on a search for compact binary coalescences where at least one binary component has a mass between 0.2  M_{⊙} and 1.0  M_{⊙} in Advanced LIGO and Advanced Virgo data collected between 1 April 2019 1500 UTC and 1 October 2019 1500 UTC. We extend our previous analyses in two main ways: we include data from the Virgo detector and we allow for more unequal mass systems, with mass ratio q≥0.1. We do not report any gravitational-wave candidates. The most significant trigger has a false alarm rate of 0.14  yr^{-1}. This implies an upper limit on the merger rate of subsolar binaries in the range [220-24200]  Gpc^{-3} yr^{-1}, depending on the chirp mass of the binary. We use this upper limit to derive astrophysical constraints on two phenomenological models that could produce subsolar-mass compact objects. One is an isotropic distribution of equal-mass primordial black holes. Using this model, we find that the fraction of dark matter in primordial black holes in the mass range 0.2  M_{⊙}<m_{PBH}<1.0  M_{⊙} is f_{PBH}≡Ω_{PBH}/Ω_{DM}≲6%. This improves existing constraints on primordial black hole abundance by a factor of ∼3. The other is a dissipative dark matter model, in which fermionic dark matter can collapse and form black holes. The upper limit on the fraction of dark matter black holes depends on the minimum mass of the black holes that can be formed: the most constraining result is obtained at M_{min}=1  M_{⊙}, where f_{DBH}≡Ω_{DBH}/Ω_{DM}≲0.003%. These are the first constraints placed on dissipative dark models by subsolar-mass analyses.

Whether prophylactic intraoperative chest drain insertion in esophageal atresia-tracheoesophageal fistula is an evidence-based practice or just a prejudice: A systematic review and meta-analysis

BACKGROUND

Various controversial practices in the management of Esophageal atresia-tracheoesophageal fistula (EA-TEF) can be noticed among pediatric surgeons. Routine intraoperative chest drain (IOCD) insertion is often debated and lacks any concrete evidence. This meta-analysis aims to compare the postoperative outcomes among newborns with and without IOCD insertion.

METHODS

The authors searched EMBASE, PubMed, Scopus, and Web of Science on 30^th April 2021. The requirement for chest drain in the postoperative period (POCD), anastomotic leak (and/or pneumothorax), mortality rate, and revisit(s) to the operation room (RVOR) were compared among two groups of newborns, i.e. groups A and B with and without IOCD insertion respectively. The statistical analysis was performed using a fixed-effects model. The pooled risk ratio (RR) and heterogeneity (I²) were calculated. The methodological quality of the studies was assessed utilizing the Downs and Black scale.

RESULTS

A total of 498 newborns were included in the present analysis. As compared to group B, newborns within group A showed no significant difference in the requirement for POCD (RR 2.47; 95% CI 0.88-6.98, p = 0.09), the occurrence of anastomotic leak and/or pneumothorax (RR 1.35; 95% CI 0.89-2.06, p = 0.16), and mortality rate (RR 2.24; 95% CI 0.81-6.26, p = 0.12). However, RVOR was significantly higher in group A (RR 1.75; 95% CI 1.07-2.87, p = 0.03). All included studies had a moderate risk of bias.

CONCLUSIONS

The present meta-analysis revealed no additional benefit of prophylactic IOCD insertion. However, due to moderate risk of bias, further studies need to be conducted for an optimal comparison between the two groups.

STUDY OF EFFECTIVENESS OF SHELTERING FROM RADIATION EXPOSURE DUE TO ACCIDENTAL RELEASE OF RADIOACTIVITY

Sheltering is one of the important protective actions as a part of emergency response during the early phases of an accident-mostly precautionary in nature. Sheltering via structural shielding reduces the direct exposure from plume/cloud shine and ground shine doses as well as the airborne radioactivity concentration and hence inhalation dose. The present study was aimed at estimating the shielding factor in the case of Indian houses for external exposure pathways using the FLUKA Monte Carlo based radiation transport code. Furthermore, the dose reduction factor due to exposure from the inhalation pathway was estimated using an indoor aerosol model. These factors were assessed for the three major types of dwellings, and they provided important inputs for decision-making for sheltering or evacuation in case of any sudden release of radionuclides into the environment.

Peri-Operative Fall in Serum Albumin Levels Correlate Well With Outcomes in Children Undergoing Emergency Abdominal Surgery: A Prospective Study From a Resource-Limited Setting

Background

Albumin is a negative acute-phase protein as its levels fall after injury, sepsis, and surgical stress. A review of the literature suggests that serum albumin level drops rapidly after surgery in adults and correlates well with the outcomes. However, there is limited data on the use of peri-operative fall in serum albumin levels as an outcome predictor in children undergoing emergency abdominal surgeries. We aim to investigate the correlation between the degree of peri-operative fall in serum albumin levels and the outcomes in children undergoing emergent abdominal surgeries.

Materials and methods

This prospective study included all children aged 2-15 years undergoing emergent abdominal surgeries between January 2019 to June 2020 at our center. Preoperative serum albumin level (A1) was recorded for all children. Postoperative day 0 serum albumin level (A2) was sent 4-6 hours following the surgery. The degree of peri-operative fall in serum albumin level (∆A) was calculated by subtracting A2 from A1. Patients were then grouped on the basis of ∆ A, i.e. groups 1 and 2 with ∆ A < 0.5 and ≥ 0.5 gm/dl respectively. Additional data like diagnosis, surgical procedure, duration of surgery, complications, and length of hospital stay were also recorded. Recorded parameters in group 1 were then compared to group 2 statistically.

Results

Fifty-six children (male to female ratio {M:F} = 1.5:1), who met the inclusion criteria during the study period, were included in the study. Groups 1 and 2 comprised 38 and 18 children respectively. The postoperative serum albumin levels were significantly lower in group 2 (p = 0.0005). Duration of surgery was significantly higher in group 2 (p = 0.0474). Complications and length of hospital stay were significantly higher in group 2 (p = 0.0107 and p = 0.0375 respectively).

Conclusion

The present study evaluated the fall in peri-operative serum albumin level (∆A) in children undergoing emergent abdominal surgery as a marker of stress. Higher values of ∆A (≥ 0.5 gm/dl) depicted a significant correlation with complications requiring re-laparotomy and a longer length of hospital stay. 

Barbed Versus Non-Barbed Suture for Pyeloplasty via the Minimally Invasive Approach: A Systematic Review and Meta-Analysis

Background: There is no agreed protocol on usage of proper and best suturing material in minimally invasive pyeloplasty. The aim of this meta-analysis was to summarize and analyze current evidence on suturing materials for laparoscopic pyeloplasty. Materials and Methods: This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Scientific databases (PubMed, Scopus, Web of Science, and EMBASE) were systematically searched for relevant comparative studies on barbed suture (BS) and non-barbed suture (NBS) in minimally invasive pyeloplasty. Results: Five comparative studies met the inclusion criteria and were included in the meta-analysis. Pooling the data demonstrated a significantly shorter operative duration in patients belonging to the BS group versus the NBS group (95% confidence interval [CI] -81.63 to -10.41, P = .01), with statistically significant estimated heterogeneity among the included studies (P < .0001). Although the incidence of redo-pyeloplasty was higher in the BS group, the pooled risk ratio (RR) for the need for redo-pyeloplasty in subjects belonging to the BS group versus the NBS group was 6.00 (95% CI 0.78-46.14), demonstrating no statistically significant difference (P = .09). A total of 5 patients developed postoperative complications. The pooled RR for the occurrence of these complication showed no significant difference among the patients belonging to both the groups (95% CI 0.22-6.05, P = .88). Conclusions: Minimally invasive pyeloplasty using BS is associated with significantly shorter operative time. The incidence of postoperative complications and requirement of redo-pyeloplasty showed no significant difference among both the treatment groups. Further randomized controlled trials need to be conducted before any definite conclusions are drawn.

Residual ctDNA after treatment predicts early relapse in patients with early-stage non-small cell lung cancer

BACKGROUND

Identification of residual disease in patients with localized non-small cell lung cancer (NSCLC) following treatment with curative intent holds promise to identify patients at risk of relapse. New methods can detect circulating tumour DNA (ctDNA) in plasma to fractional concentrations as low as a few parts per million, and clinical evidence is required to inform their use.

PATIENTS AND METHODS

We analyzed 363 serial plasma samples from 88 patients with early-stage NSCLC (48.9%/28.4%/22.7% at stage I/II/III), predominantly adenocarcinomas (62.5%), treated with curative intent by surgery (n = 61), surgery and adjuvant chemotherapy/radiotherapy (n = 8), or chemoradiotherapy (n = 19). Tumour exome sequencing identified somatic mutations and plasma was analyzed using patient-specific RaDaR™ assays with up to 48 amplicons targeting tumour-specific variants unique to each patient.

RESULTS

ctDNA was detected before treatment in 24%, 77% and 87% of patients with stage I, II and III disease, respectively, and in 26% of all longitudinal samples. The median tumour fraction detected was 0.042%, with 63% of samples <0.1% and 36% of samples <0.01%. ctDNA detection had clinical specificity >98.5% and preceded clinical detection of recurrence of the primary tumour by a median of 212.5 days. ctDNA was detected after treatment in 18/28 (64.3%) of patients who had clinical recurrence of their primary tumour. Detection within the landmark timepoint 2 weeks to 4 months after treatment end occurred in 17% of patients, and was associated with shorter recurrence-free survival [hazard ratio (HR): 14.8, P <0.00001] and overall survival (HR: 5.48, P <0.0003). ctDNA was detected 1-3 days after surgery in 25% of patients yet was not associated with disease recurrence. Detection before treatment was associated with shorter overall survival and recurrence-free survival (HR: 2.97 and 3.14, P values 0.01 and 0.003, respectively).

CONCLUSIONS

ctDNA detection after initial treatment of patients with early-stage NSCLC using sensitive patient-specific assays has potential to identify patients who may benefit from further therapeutic intervention.

Looking beyond the dartos fascia and tunica vaginalis: reviewing the stance of common adjuvant covering biomaterials in hypospadiology

Hypospadias, one of the commonest congenital anomalies in boys, can have a spectrum of clinical presentation based on the location of the meatus and the presence of chordee. The surgical repair of hypospadias involves great precision, especially in proximal varieties and redo/complex cases of hypospadias. Hypospadiologists have put in tremendous efforts to improve the outcomes of these children. The utilization of adjuvant biomaterials is one such effort that has gained significant attention over the recent years. Biomaterials are used to cover the urethral suture line in instances where the ideal covering agents (dartos fascia and tunica vaginalis) are unavailable. We reviewed the mechanism of action, current stance, and advantages/disadvantages of three commonly used adjuvant agents, i.e. autologous platelet concentrates, tissue glues, and acellular dermal matrixes. Although individual studies have highlighted the therapeutic benefits of these adjuvants, the available literature has a limited level of evidence. Moreover, it is believed that the application procedure of these covering agents needs to be scrutinized in future studies. In addition, it is suggested that the application of any covering agent right up to the meatus is non-anatomical and redundant. Well-designed randomized controlled trials with a uniform application procedure and comparing different covering agents need to be conducted in the future before any definite conclusion is drawn.

Comparison of the outcomes of testicular torsion among children presenting during the Coronavirus Disease 2019 (COVID-19) pandemic versus the pre-pandemic period: A systematic review and meta-analysis

OBJECTIVE

To evaluate whether the Coronavirus Disease 2019 (COVID-19) pandemic resulted in a prolonged duration of symptoms, a delayed presentation to the medical facility, and consequently more orchiectomy procedures among children with testicular torsion compared to the pre-COVID-19 period.

METHODS

Systematic search of four scientific databases was performed. The search terms used were (coronavirus OR novel coronavirus OR SARS-CoV-2 OR COVID-19) AND (testicular torsion OR orchidectomy OR orchiectomy OR orchidopexy OR orchiopexy). The inclusion criteria were all boys presenting with testicular torsion during the COVID-19 and pre-COVID-19 periods. A comparison of the average duration of symptoms, the proportion of children with delayed presentation (>24 h), and the proportion of children requiring orchiectomy was made among the two groups. The Downs and Black scale was used for methodological quality assessment.

RESULTS

The present meta-analysis included six comparative studies (five retrospective studies). A total of 711 patients (473 during the COVID-19 period) were included. No significant differences in the average duration of symptoms (WMD: 2.6, 95% CI -6.78 to 11.99, P = 0.59), the proportion of children with delayed presentation (RR = 1.03, 95% CI 0.52-2.02, p = 0.94), and orchiectomy rate (RR = 1.23, 95% CI 0.82-1.84, p = 0.31) were observed among the two patient groups. All studies had a moderate risk of bias.

CONCLUSION

The duration of symptoms, the proportion of children with delayed presentation, and orchiectomy rate did not significantly differ among the children with testicular torsion presenting during the COVID-19 and pre-COVID-19 periods. However, due to the moderate risk of bias, the level of evidence of the available comparative studies is limited.

Relationship Between the Mobility of Aggregates and Fluid Penetration Depth Across a Range of Fractal Dimensions Using Stokesian Dynamics

The hydrodynamic behavior of fractal aggregates plays an important role in various applications in industry and the environment, and has been a topic of interest over the past several decades. Despite this, crucial aspects such as the relationship of the mobility radius, R_m, with respect to the fractal dimension, d_f, and the fluid penetration depth, δ, have largely remained unexplored. Herein, we examine these aspects across a wide range of d_f's through a Stokesian dynamics approach. It takes into account all orders of monomer-monomer interactions to construct the resistance matrix for the entire cluster, which is assumed to be rigid. Statistical fractals created using algorithms such as diffusion limited aggregation (DLA), cluster-cluster aggregation (CCA), tunable Monte Carlo algorithm, and a deterministic Vicsek fractal, with d_f varying from 1.76 to 3, and the number of monomers ranging from 20 to 10 240 are considered. While confirming the expected asymptotic cluster-size independence of the hydrodynamic ratio, β = R_m/R_g (where R_g is the radius of gyration of the cluster), this study reveals a monotonically increasing trend for β with increasing d_f. The decay of the fluid velocity within the aggregate is quantified via the concept of penetration depth (δ). Analysis shows that the dimensionless penetration depth (δ* = δ/R_g) approaches asymptotic constancy with respect to cluster size in contrast to a weak dependency of the form δ* ∼ (R_g/a)^{-(d_f - 1)/2}, predicted by the mean-field theory (a being the monomer radius). Furthermore, the penetration depth is found to decrease rapidly, in an exponential manner, with increasing β. This establishes a quantitative relationship between the resistance experienced by the cluster and the degree of penetration of fluid into it. The implications of these results are further discussed.

Dose distribution to a random walker moving in a two-dimensional surface around a radioactive source

BACKGROUND

Modeling of dose distribution of randomly moving population around a radioactive source is a complex problem.

OBJECTIVE

The objective is to develop a model and solution techniques to estimate radiation absorbed dose to the population randomly moving around a radioactive source.

METHODS

The problem is formulated using a second-order partial differential equation; different moments of the dose distribution function are defined related to physically realizable quantities, and solutions are obtained using standard moments methods. Alternatively, numerical simulations are performed to estimate the radiation doses using Monte Carlo approach for individual positions and random motions of the people around the source.

RESULTS

A good agreement is found between average doses obtained from moments method and numerical simulations. A typical application of this model to different exposure conditions shows that the average dose is highly dependent on the population density. The study results show that average dose decreases with increase in the population density and movement area of random walker.

SIGNIFICANCE

This mathematical model can be used as a rapid assessment tool by the emergency planners in resource optimization by providing quick estimates of likely exposures for triage and emergency response.