The combined risk predictive power of frailty and hypoalbuminemia in free tissue flap reconstruction: A cohort study of 34,571 patients from the NSQIP database

INTRODUCTION

Significant morbidity and mortality are hallmarks of the functional decline seen in physically frail patients. The modified frailty index 5 (mFI-5) represents a risk predictor score that has been validated as a comorbidity-based scale in surgery. Serum albumin levels of <3.5 g/dL (hypoalbuminemia) have also been implicated with poor postoperative outcomes. However, the association between these two parameters remains to be investigated. We aimed to elucidate the interdependence of preoperative albumin levels and frailty, as evaluated by the mFI-5 score, and its reliability to prognosticate postoperative results in free flap reconstruction (FFR).

METHODS

We conducted a multicenter, retrospective cohort study and accessed the ACS National Surgical Quality Improvement Program (ACS-NSQIP) from 2008 to 2021. We identified all adult patients (≥18 years of age) who underwent a FFR. We extracted perioperative data and lab values including albumin. Multivariable linear and logistic regression analyses were performed to identify independent risk predictors. Main outcomes involved mortality, length of hospital stay, reoperation, medical and surgical complications, and discharge destination within the 30-day postoperative period.

RESULTS

A total of 34,571 patients were included in the study, with an average age of 53.9 years (standard deviation [SD] 12.2) and an average body mass index (BMI) of 28.8 (SD 6.1). Of these patients, 7484 were male (21.6%), whereas 22,363 (64.7%) had no frailty (mFI = 0). Additionally, 9466 patients had a frailty score of 1 (27.4%), 2505 had a score of 2 (7.2%), 226 had a score of 3 (0.7%), and 11 had a score of 4 or higher (0.0%). Albumin levels were available for 16,250 patients (47.0%), and among them, 1334 (8.2%) had hypoalbuminemia. Regression analyses showed that higher mFI scores were independent predictors of any, surgical, and medical complications, as well as increased rates of reoperations, unplanned readmissions, and prolonged hospital stays. Hypoalbuminemia independently predicted any, surgical, and medical complications, and higher mortality, reoperation, and longer hospital stay. When both frailty and albumin levels (mFI-5 and albumin) were considered together, this combined assessment was found to be a more accurate predictor of all major outcomes (any, medical and surgical complications, mortality, and reoperation). Further, our analysis identified a weak negative correlation between serum albumin levels and mFI scores (Spearman R: -.1; p < .0001).

CONCLUSION

In conclusion, this cohort study highlights the association of hypoalbuminemia with adverse postoperative outcomes, including those not directly related to frailty. Simultaneously, higher mFI scores independently predicted outcomes not associated with hypoalbuminemia. Stemming from these findings, we recommend considering both serum albumin levels and frailty in patients receiving FFR. This perioperative algorithm may help provide more individualized planning including multidisciplinary care and pre and posthabilitation.

In vivo engineering and transplantation of axially vascularized and epithelialized flaps in rats

The arteriovenous loop (AVL) model allows the in vivo engineering of axially vascularized flaps, the so called AVL flaps. Although AVL flaps can be transplanted microsurgically to cover tissue defects, they lack an epithelial layer on the surface. Therefore, the objective of this study was to engineer axially vascularized AVL flaps with an accompanying epithelial layer for local defect reconstruction. In this study AVLs were established in 20 male Lewis rats. Minimally invasive injection of keratinocytes onto the surface of the AVL flaps was performed on postoperative day (POD) 21. AVL flaps were explanted from 12 rats on POD 24 or POD 30, then the epithelium formed by the keratinocytes on the surface of the flaps was evaluated using immunofluorescence staining. In six other rats, the AVL flap was locally transposed to cover a critical defect in the rats' leg on POD 30 and explanted for analysis on POD 40. In two control rats, sodium chloride was applied instead of keratinocytes. These control flaps were also transplanted on POD 30 and explanted on POD 40. Our results revealed that three days after keratinocyte application, a loose single-layered epithelium was observed histologically on the AVL flaps surface, whereas after nine days, a multilayered and structured epithelium had grown. The epithelium on the transplanted AVL flaps showed its physiological differentiation, when being exposed to an air-liquid interface. Histologically a layered epithelium identical to the rats' regular skin was formed. In the sodium chloride control group, no epithelium had been grown. This study clearly demonstrates that axially vascularized AVL flaps can be processed in the subcutaneous chamber by minimally invasive injection of keratinocytes. Thus, AVL flaps with an intact epithelial layer were engineered and could be successfully transplanted for local defect coverage in a small animal model.

Free Flap Reconstruction of Sternal Defects after Cardiac Surgery: An Algorithmic Approach for Dealing with Sparse Recipient Vessels

Background

Sparsity of recipient vessels poses a challenge for microsurgical free flap reconstruction of sternal defects following deep sternal wound infection after cardiac surgery.

Methods

From January 2013, a standardized algorithm for dealing with sparse recipient vessels was strictly followed. In this retrospective study including 75 patients, we compared operative details, surgical complications, and reconstructive outcomes of patients treated according to this algorithm (group A: January 2013-May 2021; n = 46) with a historical control group (group B: January 2000-December 2012, n = 29).

Results

The left internal mammary artery had been harvested for arterial bypass grafting in 40 of 46 cases (87%) in group A and in all cases in group B. The right internal mammary artery (RIMA) and right internal mammary vein (RIMV) were the first choice as recipient vessels. In case of unsuitability of the RIMV, a right cephalic vein (CV) turndown was used for venous outflow. If both RIMA and RIMV proved insufficient, a single-stage arterio-venous loop (AVL) between the CV and subclavian artery (CV-SA AVL), CV and thoracoacromial artery (CV-TA AVL), or subclavian artery and subclavian vein (SA-SV AVL) was established. The algorithmic approach significantly reduced partial flap necrosis [group A: n = 3 (7%) versus group b: n = 7 (24%); P = 0.04], and overall operation time [group A: 360 ± 88 min versus group B: 415 ± 80 min; P = 0.01].

Conclusions

Standardized approaches improve clinical outcomes in microsurgical free flap sternal reconstruction after cardiac surgery.

Robot-Assisted Pelvic Dissection for Enlarged Lymph Nodes in Melanoma Improves Recovery with Equivalent Oncological Outcomes to Open Pelvic Dissection

BACKGROUND

Robot-assisted pelvic lymph node dissection (rPLND) has been reported in heterogenous groups of patients with melanoma, including macroscopic or at-high-risk-for microscopic metastasis. With changing indications for surgery in melanoma, and availability of effective systemic therapies, pelvic dissection is now performed for clinically detected bulky lymph node metastasis followed by adjuvant drug therapy. rPLND has not been compared with open pelvic lymph node dissection (oPLND) for modern practice.

METHODS

All patients undergoing pelvic node dissection for macroscopic melanoma at a single institution were reviewed as a cohort, observational study.

RESULTS

Twenty-two pelvic lymph node dissections were identified (8 oPLND; 14 rPLND). The number of pelvic lymph nodes removed was similar (median oPLND 6.5 (interquartile range [IQR] 6.0-12.5] versus rPLND 6.0 [3.75-9.0]), with frequent matted nodes (11/22, 50.0%). Operative time (median oPLND 130 min [IQR 95.5-182] versus rPLND 126 min [IQR 97.8-160]) and complications (Clavien-Dindo scale) were similar. Length of hospital stay (median 5.34 days (IQR 3.77-6.94) versus 1.98 days (IQR 1.39-3.50) and time to postoperative adjuvant therapy (median 11.6 weeks [IQR 10.6-18.5] versus 7.71 weeks [IQR 6.29-10.4]) were shorter in the rPLND group. No differences in pelvic lymph node recurrence (p = 0.984), distant metastatic recurrence (p = 0.678), or melanoma-specific survival (p = 0.655) were seen (median follow-up 21.1 months [rPLND] and 25.7 months [oPLND]).

CONCLUSIONS

rPLND is an effective way to remove bulky pelvic lymph nodes in melanoma, with a shorter recovery and reduced interval to initiating adjuvant therapy compared with oPLND. This group of patients may especially benefit from neoadjuvant systemic approaches to management.

Comparative study of non-contrast silent and time-of-flight magnetic resonance angiographic sequences in the evaluation of intracranial dural arteriovenous fistula

AIM

To compare the performance of two non-contrast magnetic resonance angiography (MRA) sequences, silent MRA and time of flight (TOF) MRA, in the evaluation of intracranial dural arteriovenous fistula (DAVF).

MATERIALS AND METHODS

Forty consecutive patients with DAVF were enrolled and evaluated prospectively using silent MRA, TOF MRA, and digital subtraction angiography (DSA). The location, Cognard classification, arterial feeders, and venous drainage were evaluated. The therapeutic strategy and possible route were predicted on both silent and TOF MRA and these were compared with DSA during subsequent endovascular treatment.

RESULTS

Sensitivity and accuracy of silent and TOF MRA for localisation (96.4% versus 96% and 96% versus 95%, respectively) and classification (96% versus 94% and 96% versus 93.5%, respectively) were high. Silent MRA showed higher sensitivity than TOF MRA for arterial feeders and draining veins (87% versus 79% and 81.6% versus 67%). This improved to a sensitivity of 96.4% and 89% when prominent feeders were considered. The sensitivity and accuracy were 92.6% and 85.8% for immediate draining veins. Both silent and TOF MRA were accurate for therapeutic planning (96% versus 85%), although silent MRA was more accurate.

CONCLUSION

Silent MRA can more reliably evaluate the various angioarchtectural components of DAVF compared to TOF MRA.

Ultrasound-An Easy Available and Useful Point-of-Care Adjunct for Clinical Decision-Making in Hand Infections: Review of the Literature and a Case Series

ABSTRACT

Initial findings of hand infections warrant a thorough treatment strategy depending on the progress of the infection. The decision for surgical treatment can be unclear. Searching to improve the quality of diagnostics, we reviewed the literature regarding the use of point-of-care ultrasound (PCUS) in hand infections and analyzed patients undergoing decision-making with PCUS. We searched PubMed, Scopus, Cochrane Register, and Google Scholar for the use of PCUS in therapy planning in infections of the hand. In addition, we screened our patients from July 1, 2020, to November 30, 2020, to validate the potential benefit of ultrasound examination in suspected hand infections. We evaluated initial clinical examinations versus blinded sonographic assessments in the context of correct decision to proceed with surgery or conservative treatment. Two thousand forty-eight studies within the topic were identified, but only 9 studies were found eligible to be included with a total of 88 patients. The studies illustrate that ultrasound can be performed on all patients, including children and pregnant women, and can be performed in a timely manner. In our retrospective analysis of 20 patients with suspected hand infection, the clinical and ultrasound assessment led to surgery in 13 cases. Of those 13 patients, 7 revealed intraoperative pus. By retrospective assessment of solely the ultrasound images, surgery would have been indicated in 9 cases, including all 7 cases with intraoperative pus. Clinical examination and ultrasound can help in detecting infections of the hand. Ultrasound examination, however, seems to yield a lower false-positive rate than clinical examination. Ultrasound could be a valuable addition to clinical examination.

Dexmedetomidine for end of life sedation: retrospective cohort comparison study

OBJECTIVES

Infused sedatives are often utilised to alleviate distress at the end of life. Which sedative best achieves this is unknown. This study compares breakthrough medication requirements of patients treated with the novel agent dexmedetomidine compared with patients treated with standard-care sedatives.

METHODS

A retrospective cross-cohort comparison. Two studies of patients at the end of life under sedation at the same palliative care unit, one utilising novel sedatives, and the other standard care were compared. Breakthrough medication requirements were compared using paired t-tests, including opioids, benzodiazepines and anticholinergics. Changes in background infusions were compared.

RESULTS

The dexmedetomidine cohort required less breakthrough interventions per day compared with the standard care group, the reduction was significant (2.2 vs 3.9, p=0.003). There was a significant difference in benzodiazepine requirements, with the dexmedetomidine cohort requiring fewer doses per day than the standard care cohort (1.1 vs 0.6, p=0.03). Anticholinergics were more commonly utilised in the standard care cohort but there was no significant difference (p=0.22). Opioid requirements were similar across cohorts with comparable rates of breakthrough use and infusion increases.

CONCLUSIONS

This study demonstrates a reduction in breakthrough medication requirements, particularly benzodiazepines, for patients sedated with dexmedetomidine at end of life.

Comparison of Decellularized Human Dermal Scaffolds versus Bovine Collagen/Elastin Matrices for Engineering of Soft-Tissue Flaps

BACKGROUND

Free flap-based soft-tissue reconstruction comes at the price of donor-site morbidity. The arteriovenous loop (AVL) technique can overcome this issue by allowing for the de novo generation of axially vascularized soft-tissue flaps from vein grafts embedded into different matrices. Application of the AVL technique has been limited by insufficient long-term volume retention and poor tissue stability. The authors investigated the suitability of a novel human dermal scaffold to improve volume retention and tissue stability.

METHODS

AVLs were created in 28 immunocompetent rats and embedded in either decellularized human dermal scaffolds (experimental group, n = 14) (Epiflex) or bovine collagen/elastin matrices (control group, n = 14) (MatriDerm) in subcutaneous polytetrafluoroethylene chambers. The weight and volume of engineered tissues, the extent of angiogenesis, and the proportion of proliferating cells were compared between groups on postoperative days (PODs) 21 and 28 by means of immunohistochemistry and micro-computed tomography.

RESULTS

On POD 28, both groups displayed homogeneous microvascular networks on histopathology and micro-computed tomography. Mean microvessel counts and surface areas and the percentage of proliferating cells did not differ between the groups. However, the experimental human scaffold group displayed significantly smaller volume loss and significantly less tissue degradation compared with bovine matrix controls (volume retention, 102% ± 5% versus 27% ± 7% on POD 21, and 79% ± 12% versus 12% ± 7% on POD 28, respectively; P < 0.0001).

CONCLUSION

Compared with bovine matrices, decellularized human scaffolds allow for superior volume retention and tissue stability of de novo engineered soft-tissue AVL flaps in rats.

CLINICAL RELEVANCE STATEMENT

AVLs allow for the de novo generation of vascularized soft-tissue flaps. However, insufficient long-term volume retention is still an issue. The authors' study shows that decellularized human matrices guarantee superior volume stability of de novo grown soft-tissue flaps in rats.

Enzymatic Carboxylation of Resorcinol in Aqueous Triethanolamine at Elevated CO2 Pressure

The fixation of CO2 by enzymatic carboxylation for production of valuable carboxylic acids is one way to recycle carbon. Unfortunately, this type of reaction is limited by an unfavourable thermodynamic equilibrium. An excess of the C1 substrate is required to increase conversions. Solvents with a high CO2 solubility, such as amines, can provide the C1 substrate in excess. Here, we report on the effect of CO2 pressures up to 1100 kPa on the enzymatic carboxylation of resorcinol in aqueous triethanolamine. Equilibrium yields correlate to the bicarbonate concentration. However, inhibition is observed at elevated pressure, severely reducing the enzyme activity. The reaction yields were reduced at higher pressures, whereas at ambient pressure, higher yields were achieved. Overall, CO2 pressures above 100 kPa have been demonstrated to be counterproductive for improving the biotransformation, as productivity decreases rapidly for only a modest improvement in conversion. It is expected that CO2 carbamylation intensifies at elevated CO2 pressures, causing the inhibition of the enzyme. To further increase the reaction yield, the in situ product precipitation is tested by the addition of the quaternary ammonium salt tetrabutylammonium bromide.

Evaluation of quality of life's prognostic factors in people with functional seizures

AIMS

Functional non-epileptic seizures significantly impact the quality of life of patients. We aimed to identify prognostic factors associated with the quality of life in individuals with functional non-epileptic seizures.

SUBJECTS AND METHODS

Adult patients diagnosed with definite or documented functional seizures based on LaFrance's criteria (n=72) were enrolled at the time of diagnosis. Quality of life was assessed using the Quality of Life in Epilepsy Inventory-31 (QOLIE-31) at diagnosis and at a six-month follow-up. Demographic and medical information was collected, and psychiatric comorbidities were evaluated using validated scales.

RESULTS

Comparisons between diagnosis and follow-up did not reveal any factors associated with improvement in quality of life at six months after diagnosis. However, multivariable analysis, adjusted for age, sex, diagnosis delay, and frequency of functional seizures showed a significant cross-sectional relationship with a QOLIE-31 score decrease of 0.66 [95% CI -0.93;-0.39], -0.32 [-0.61; -0.03], and -0.22 [-0.42; -0.02] for an increase of 1 point of BDI-2 score, BAI score, and CTQ score respectively.

CONCLUSION

Psychiatric comorbidities, particularly depression and anxiety, are associated with worse quality of life in patients with functional seizures. This underscores the crucial importance of multidisciplinary care involving both neurological and psychiatric expertise when managing individuals with functional seizures.

Pulmonary alveolar proteinosis diagnosis after re‑evaluation for chronic cough unresponsive to empirical antituberculosis therapy

This study extends the reports of PAP in SA, in this case a 29-year- old HIV-negative black African woman with no history of smoking. Patients with respiratory symptoms who are microbiologically negative for TB should be carefully evaluated for an alternative diagnosis.

Methods for Engineering Binders to Multi-Pass Membrane Proteins

Numerous potential drug targets, including G-protein-coupled receptors and ion channel proteins, reside on the cell surface as multi-pass membrane proteins. Unfortunately, despite advances in engineering technologies, engineering biologics against multi-pass membrane proteins remains a formidable task. In this review, we focus on the different methods used to prepare/present multi-pass transmembrane proteins for engineering target-specific biologics such as antibodies, nanobodies and synthetic scaffold proteins. The engineered biologics exhibit high specificity and affinity, and have broad applications as therapeutics, probes for cell staining and chaperones for promoting protein crystallization. We primarily cover publications on this topic from the past 10 years, with a focus on the different formats of multi-pass transmembrane proteins. Finally, the remaining challenges facing this field and new technologies developed to overcome a number of obstacles are discussed.

An exploration of testicular cancer survivors' experience of ejaculatory dysfunction following retroperitoneal lymph node dissection-a sub-study of the PREPARE clinical trial

PURPOSE

Ejaculatory dysfunction secondary to retrograde ejaculation or anejaculation is a complication of retroperitoneal lymph node dissection (RPLND) for survivors of testicular cancer. We explored survivors' experiences of ejaculatory dysfunction following RPLND.

METHODS

In a sub-study of a single-arm phase 2 clinical trial (ACTRN12622000537752/12622000542796), participants reporting ejaculatory dysfunction ≥ 6 months following RPLND were invited to complete semi-structured interviews. Purposive sampling was used. Interviews continued until thematic saturation occurred, and codebook thematic analysis of interviews was performed.

RESULTS

Of 58 individuals recruited to the trial, 33 (57%) reported ejaculatory dysfunction. Of these, 32 (97%) agreed to interview and 15 participated. Participants interviewed had median age 34 years (range 24-66), 12 (80%) in a long-term relationship with median time from surgery 36 months (range 11-112). Three overarching themes were identified. The first reflected the value of RPLND despite ejaculatory dysfunction. The second illuminated the impact(s) of ejaculatory dysfunction closely mapped to life stage, with flow-on impacts to fertility, sex, psychological wellbeing and communication. The third reflected information needs. Fertility was a substantial source of concern for some participants. Ejaculatory dysfunction had no effect on sex for some, whilst for others, sex was less pleasurable. Some reported benefits. Few reported ejaculatory dysfunction challenged masculinity, confidence, or self-esteem.

CONCLUSIONS

Future research should examine interventions to reduce distress related to fertility, challenged masculinity and body image.

IMPLICATIONS FOR CANCER SURVIVORS

Whilst most participants considered ejaculatory dysfunction to have little impact on their sexual function and relationships, some reported significant difficulties varying by life stage and relationship status.

Gastric Radiotherapy in the UK - Current Practice and Opinion on Future Directions

PURPOSE/OBJECTIVE(S)

Gastric radiotherapy (RT) is more commonly practiced in the US compared to the UK, where postoperative chemoradiotherapy (CRT) is reserved for selected high-risk patients, and preoperative CRT is not standard of care pending the results of phase 3 trials, TOPGEAR and CRITICSII. CRT for inoperable, non-metastatic gastric cancer is also not recommended in the UK, despite being listed in NCCN guidelines. Recent systematic review of definitive gastric CRT (dCRT) conducted by the authors found median overall survival of 11-26.4 months, clinical complete response rates of 8-45% and acceptable rates of ≥G3 toxicity, supporting further research. Given these promising findings and perceived low uptake of gastric RT in the UK, we set out to establish current UK practice, opinion and RT technique to inform the development of a UK gastric RT protocol and future clinical trials.

MATERIALS/METHODS

A 19 question survey was developed. Following local ethical approval and pilot by 4 clinical oncologists, the final survey was distributed electronically on 13/12/22 to UK Consultant Clinical Oncologists specializing in esophago-gastric (OG) cancer. Responses were anonymous. Survey was closed 6/2/23 and data analyzed using JISC/spreadsheet software.

RESULTS

A total of 43 clinicians completed the survey. For gastric cancer, 28.6%, 7.1% and 9.5% would agree/strongly agree with use of postoperative (postopRT), preoperative (preopRT) or definitive RT (dRT) respectively, compared to 26.2%, 45.2% and 46.6% for type III gastro-esophageal junction tumors. 93% had prescribed palliative gastric RT in the last 3 years compared to 40.5% postopRT, 16.7% dRT and 9.5% preopRT. Main reasons for infrequent use were; rarely indicated within standard UK practice 88.4%, lack of UK gastric RT protocol 53.5%, toxicity concerns 44.2%. 45Gy/25# was most commonly used for preopRT (66%) and postopRT (86%), and 50Gy/25# for dRT (58%). 96% use IMRT/VMAT, 85% CT simulation with IV/oral contrast, 69% gastric filling protocol and 54% 4DCT. When ranked out of 10 (1 = low 10 = high), clinician confidence in accurately delineating gastric volumes mean rank was 4.33 for postopRT, with 9% rating ≥8/10, and 4.52 for dCRT/preopRT with 17% rating ≥8/10. However, 48.8% were experienced in outlining upper abdominal nodes and 62.8% duodenum. 93% would find a detailed outlining protocol useful, 81.4% wanted some form of peer review, 76.7% a nodal atlas, and 74.4% a workshop with an expert. 77.6% would be supportive of a future clinical trial of dCRT, with 23.4% needing more supporting evidence. No-one would not support a future trial in this setting.

CONCLUSION

Gastric RT is not often practiced in the UK, due to lacking evidence and toxicity concerns. Given the growing evidence and supportive OG community, it is time to consider a trial of dCRT in the UK, which must include detailed RT protocols, atlases and educational materials to improve clinician confidence and ensure good RT quality assurance.

Impact of the COVID-19 Pandemic on Outcomes for Patients with Lung Cancer Receiving Curative-intent Radiotherapy in the UK

AIMS

Previous work found that during the first wave of the COVID-19 pandemic, 34% of patients with lung cancer treated with curative-intent radiotherapy in the UK had a change to their centre's usual standard of care treatment (Banfill et al. Clin Oncol 2022;34:19-27). We present the impact of these changes on patient outcomes.

MATERIALS AND METHODS

The COVID-RT Lung database was a prospective multicentre UK cohort study including patients with stage I-III lung cancer referred for and/or treated with radical radiotherapy between April and October 2020. Data were collected on patient demographics, radiotherapy and systemic treatments, toxicity, relapse and death. Multivariable Cox and logistic regression were used to assess the impact of having a change to radiotherapy on survival, distant relapse and grade ≥3 acute toxicity. The impact of omitting chemotherapy on survival and relapse was assessed using multivariable Cox regression.

RESULTS

Patient and follow-up forms were available for 1280 patients. Seven hundred and sixty-five (59.8%) patients were aged over 70 years and 603 (47.1%) were female. The median follow-up was 213 days (119, 376). Patients with stage I-II non-small cell lung cancer (NSCLC) who had a change to their radiotherapy had no significant increase in distant relapse (P = 0.859) or death (P = 0.884); however, they did have increased odds of grade ≥3 acute toxicity (P = 0.0348). Patients with stage III NSCLC who had a change to their radiotherapy had no significant increase in distant relapse (P = 0.216) or death (P = 0.789); however, they did have increased odds of grade ≥3 acute toxicity (P < 0.001). Patients with stage III NSCLC who had their chemotherapy omitted had no significant increase in distant relapse (P = 0.0827) or death (P = 0.0661).

CONCLUSION

This study suggests that changes to radiotherapy and chemotherapy made in response to the COVID-19 pandemic did not significantly affect distant relapse or survival. Changes to radiotherapy, namely increased hypofractionation, led to increased odds of grade ≥3 acute toxicity. These results are important, as hypofractionated treatments can help to reduce hospital attendances in the context of potential future emergency situations.

A Retrospective Matched-Pair Analysis of Long-term Outcomes after Successful Lower Extremity Free Flap Salvage

BACKGROUND

 Pedicle occlusion with total free flap loss after microvascular lower extremity reconstruction is a considerably rare yet devastating complication. Fortunately, in the majority of cases, emergency salvage takebacks of compromised free flaps are initiated in a timely manner. In this report, we present our analysis of long-term outcomes following transient vascular compromise mitigated through successful free flap salvage in the lower extremity.

METHODS

 We performed a single-center retrospective matched-pair analysis of 46 patients with lower extremity free flap reconstructions. Cases underwent successful revisions of microvascular compromise (n = 23), whereas controls had uneventful postoperative courses (n = 23). Patient-reported outcome questionnaires and physical evaluations were used to assess general quality of life, functional outcomes, and cosmesis (Lower Extremity Functional Scale [LEFS], Lower Limb Outcomes Questionnaire [LLOQ], Short Form 36 (SF-36), Vancouver Scar Scale [VSS]). The mean follow-up time was 4.4 years.

RESULTS

 The health-related quality of life assessed by the SF-36 did not differ significantly between both groups in any of the subscales (p ≥ 0.15 for all subscales). Functional outcomes did not show significant differences between both groups according to the LEFS (p = 0.78) and LLOQ (p = 0.45). The overall scar appearance assessed by the VSS showed significantly poorer cosmesis in the re-exploration group (p = 0.014).

CONCLUSION

 Salvage of compromised free flaps in the lower extremity yields similar long-term outcomes compared to noncompromised free flaps with regard to function and quality of life. However, free flap revisions may lead to impaired scar formation. This study provides further evidence that the opportunity for urgent re-exploration is indispensable.

Acetylation reprograms MITF target selectivity and residence time

The ability of transcription factors to discriminate between different classes of binding sites associated with specific biological functions underpins effective gene regulation in development and homeostasis. How this is achieved is poorly understood. The microphthalmia-associated transcription factor MITF is a lineage-survival oncogene that plays a crucial role in melanocyte development and melanoma. MITF suppresses invasion, reprograms metabolism and promotes both proliferation and differentiation. How MITF distinguishes between differentiation and proliferation-associated targets is unknown. Here we show that compared to many transcription factors MITF exhibits a very long residence time which is reduced by p300/CBP-mediated MITF acetylation at K206. While K206 acetylation also decreases genome-wide MITF DNA-binding affinity, it preferentially directs DNA binding away from differentiation-associated CATGTG motifs toward CACGTG elements. The results reveal an acetylation-mediated switch that suppresses differentiation and provides a mechanistic explanation of why a human K206Q MITF mutation is associated with Waardenburg syndrome.

Click display: a rapid and efficient in vitro protein display method for directed evolution

We describe a novel method for in vitro protein display-click display-that does not depend on maintaining RNA integrity during biopanning and yields covalently linked protein-cDNA complexes from double-stranded input DNA within 2 h. The display is achieved in a one-pot format encompassing transcription, translation and reverse transcription reactions in series. Stable linkage between proteins and the encoding cDNA is mediated by a modified DNA linker-ML-generated via a click chemistry reaction between a puromycin-containing oligo and a cDNA synthesis primer. Biopanning of a click-displayed mock library coupled with next-generation sequencing analysis revealed >600-fold enrichment of target binders within a single round of panning. A synthetic library of Designed Ankyrin Repeat Proteins (DARPins) with ∼1012 individual members was generated using click display in a 25-μl reaction and six rounds of library panning against a model protein yielded a panel of nanomolar binders. This study establishes click display as a powerful tool for protein binder discovery/engineering and provides a convenient platform for in vitro biopanning selection even in RNase-rich environments such as on whole cells.

Feeding rumen-protected lysine prepartum alters placental metabolism at a transcriptional level

Rumen-protected Lys (RPL) fed to Holstein cows prepartum resulted in a greater intake and improved health of their calves during the first 6 wk of life. However, whether increased supply of Lys in late gestation can influence placental tissue and, if so, which pathways are affected remain to be investigated. Therefore, we hypothesize that feeding RPL during late gestation could modulate placental metabolism, allowing for improved passage of nutrients to the fetus and thus influencing the offspring development. Therefore, we aimed to determine the effects of feeding RPL (AjiPro-L Generation 3, Ajinomoto Health and Nutrition North America) prepartum (0.54% DM of TMR) on mRNA gene expression profiles of placental samples of Holstein cows. Seventy multiparous Holstein cows were randomly assigned to 1 of 2 dietary treatments, consisting of TMR top-dressed with RPL (PRE-L) or without (control, CON), fed from 27 ± 5 d prepartum until calving. After natural delivery (6.87 ± 3.32 h), placentas were rinsed with physiological saline (0.9% sodium chloride solution) to clean any dirtiness from the environment and weighed. Then, 3 placentomes were collected, one from each placental region (cranial, central, and caudal), combined and flash-frozen in liquid nitrogen to evaluate the expression of transcripts and proteins related to protein metabolism and inflammation. Placental weights did not differ from cows in PRE-L (15.5 ± 4.03 kg) and cows in CON (14.5 ± 4.03 kg). Feeding RPL prepartum downregulated the expression of NOS3 (nitric oxide synthase 3), involved in vasodilation processes, and SOD1, which encodes the enzyme superoxide dismutase, involved in oxidative stress processes. Additionally, feeding RPL prepartum upregulated the expression of transcripts involved in energy metabolism (SLC2A3, glucose transporter 3; and PCK1, phosphoenolpyruvate carboxykinase 1), placental metabolism and cell proliferation (FGF2, fibroblast growth factor 2; FGF2R, fibroblast growth factor 2 receptor; and PGF, placental growth factor), Met metabolism (MAT2A, methionine adenosyltransferase 2-α), and tended to upregulate IGF2R (insulin-like growth factor 2 receptor). Placental FGF2 and LRP1 (low-density lipoprotein receptor-related protein 1) protein abundance were greater for cows that received RPL prepartum than cows in CON. In conclusion, feeding RPL to prepartum dairy cows altered uteroplacental expression of genes and proteins involved in cell proliferation, and in metabolism and transport of glucose. Such changes are illustrated by increased expression of SLC2A3 and PCK1 and increased protein abundance of FGF2 and LRP1 in uteroplacental tissue of cows consuming RPL.

Childhood-Onset Lupus Nephritis in the Childhood Arthritis and Rheumatology Research Alliance Registry: Short-Term Kidney Status and Variation in Care

OBJECTIVE

The goal was to characterize short-term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood-onset systemic lupus erythematosus (cSLE) and nephritis.

METHODS

We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy-proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded.

RESULTS

We identified 222 patients with kidney biopsy-proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8-29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21-12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01-1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers.

CONCLUSION

In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short-term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long-term kidney outcomes.

Dual mobility prosthesis for trapeziometacarpal osteoarthritis: results from a prospective study of 55 prostheses

This prospective study evaluated outcomes after trapeziometacarpal joint replacement with a dual mobility prosthesis (Touch®) in 55 thumbs (52 patients) with a mean follow-up of 25 months (range 12-36). Pre- and postoperative assessments included pain, range of motion, the Kapandji index, pinch- and grip strength, as well as functional scores and radiological parameters. Mean preoperative metacarpophalangeal joint hyperextension of 19° (range 15°-28°) showed a significant correction after 1 year with a mean value of 2° (range 0°-5°). Mean Quick Disabilities of the Hand, Shoulder and Arm score was 14 (range 6-28), and Michigan Hand Questionnaire 82 (range 67-92). No revisions due to infection, loosening, dislocation or material failure occurred during follow-up. The dual mobility trapeziometacarpal joint prosthesis was a reliable treatment option to decrease pain, improve motion, strength and pre-existing metacarpophalangeal joint hyperextension at short-term follow-up.Level of evidence: IV.

[The conjoined latissimus dorsi and parascapular free flap for reconstruction of extensive soft tissue defects]

OBJECTIVE

Durable and resilient soft tissue reconstruction of vast defects of the extremities or the torso.

INDICATIONS

Reconstruction of disproportionately large defects, particularly in cases of simultaneous bone and joint reconstruction.

CONTRAINDICATIONS

History of surgery or irradiation of upper back and axilla, impossibility of surgery under lateral positioning; relative contraindications in wheelchair users, hemiplegics, or amputees.

SURGICAL TECHNIQUE

General anesthesia and lateral positioning. First, the parascapular flap is harvested, with the initial skin incision made medially in order to identify the medial triangular space and the circumflex scapular artery. Flap raising then proceeds from caudal to cranial. Second, the latissimus dorsi is harvested, with the lateral border being dissected free first, before the thoracodorsal vessels are visualized on its undersurface. Flap raising then proceeds from caudal to cranial. Third, the parascapular flap is advanced through the medial triangular space. If the circumflex scapular and thoracodorsal vessels originate separately from the subscapular axis, an in-flap anastomosis is warranted. Subsequent microvascular anastomoses should be performed outside the zone of injury, typically in an end-to-end fashion of the vein and end-to-side fashion of the artery.

POSTOPERATIVE MANAGEMENT

Postoperative anticoagulation with low-molecular-weight heparin under anti-Xa monitoring (semitherapeutic in normal-risk and therapeutic in high-risk cases). Hourly clinical assessment of flap perfusion for 5 consecutive days, followed by stepwise relaxation of immobilization and commencement of dangling procedures in cases of lower extremity reconstruction.

RESULTS

Between 2013 and 2018, 74 conjoined latissimus dorsi and parascapular flaps were transplanted to cover vast defects of the lower (n = 66) and upper extremity (n = 8). The mean defect size was 723 ± 482 cm² and the mean flap size was 635 ± 203 cm². Eight flaps required in-flap anastomoses for separate vascular origins. There was no case of total flap loss.

Reconstruction of Hand and Foot Defects with Free Serratus Carpaccio Flap and Free Serratus Fascia Flap: A Comparative Retrospective Study of Surgical Outcomes

BACKGROUND

Defects of the hand and foot often require an individualized reconstructive approach, due to their unique functional and aesthetic characteristics. Transferred tissues should be thin, pliable, and durable, with free fascial flaps meeting these requirements. This study aimed to evaluate the serratus fascia flap and the serratus carpaccio flap, which is a modification of the fascia flap, by including a thin muscle layer, with the goal of enhancing flap resilience and lowering morbidity rates.

METHODS

Between January 2000 and December 2017, 31 patients underwent microsurgical reconstruction of the hand or foot either by serratus fascia flap (fascia group) or serratus carpaccio flap (carpaccio group). The serratus fascia flaps were mainly harvested between 2000 and 2012, and the serratus carpaccio flaps between 2013 and 2017. Patient records were reviewed retrospectively, regarding demographics, complications, overall flap survival, additional revision surgeries, and surgical outcome. Categorical variables were compared using Fisher's exact test and continuous data with the Mann-Whitney tests. Logistic regression was used to examine the correlation between comorbidities and postoperative complication rates. Differences were considered significant when p < 0.05.

RESULTS

The fascia group consisted of 17 patients and the carpaccio group of 14 patients. The average patient age in the fascia group was 39.2 ± 10.5 years, and it was 39.1 ± 14.7 years in the carpaccio group. Overall complication rates were significantly lower in the carpaccio group than in the fascia group (28.6% vs. 70.6%, p = 0.03). The rates of overall flap survival (85.7% in the carpaccio group vs. 74.5% in the fascia group, p = 0.66) and partial flap loss (14.3% in the carpaccio group vs. 47.1% in the fascia group, p = 0.07) did not differ significantly among both groups. One postoperative hematoma of the donor site requiring revision surgery was reported in the carpaccio group (7.1%, p = 0.45) while no donor-site morbidity was reported in the fascia group.

CONCLUSIONS

Our findings indicate that the serratus carpaccio flap presents a promising alternative to the serratus fascia flap. This modification has proven to be effective in substantially reducing postoperative complications requiring additional surgical interventions. Therefore, the serratus carpaccio flap can be considered a dependable reconstructive option for addressing complex soft tissue defects of the hand and foot, with complication rates that are within an acceptable range.

Scalp Reconstruction Using the Latissimus Dorsi Free Flap: A 12-Year Experience

BACKGROUND

Complex scalp defects are regularly reconstructed using microvascular tissue transfer. The latissimus dorsi free flap is one of the workhorse flaps used in scalp reconstruction. These cases necessitate, particularly in the elderly, a close cooperation between plastic surgeons and neurosurgeons. The purpose of this study was to evaluate the suitability of the latissimus dorsi free flap for complex scalp reconstructions and to analyze potential risk factors.

METHODS

A retrospective study identified 43 patients undergoing complex scalp reconstruction using a latissimus dorsi free flap at our department between 2010 and 2022.

RESULTS

The mean patient age was 61 ± 18 years. Defects were mostly caused by oncologic tumor resections (n = 23; 55%), exposure to a cranioplasty (n = 10; 23%) or infection (n = 4; 9%). The most frequent recipient vessels were the superficial temporal artery (n = 28; 65%), external carotid artery (n = 12; 28%) and the venae comitantes (n = 28; 65%), external jugular vein (n = 6; 14%). The reconstructive success rate was 97.7%. There was one total flap loss (2%). Partial flap loss occurred in five cases (12%). Follow-up was 8 ± 12 months. Major complications were seen in 13 cases, resulting in a revision rate of 26%. Multivariate logistic regression identified active tobacco use as the only risk factor for major complications (odds ratio 8.9; p = 0.04).

CONCLUSION

Reconstruction of complex scalp defects using the latissimus dorsi free flap yielded high success rates. Among the potential risk factors, active tobacco use seems to affect the outcome of complex scalp reconstructions.

Acellular Human Placenta Small-Diameter Vessels as a Favorable Source of Super-Microsurgical Vascular Replacements: A Proof of Concept

In this study, we aimed to evaluate the human placenta as a source of blood vessels that can be harvested for vascular graft fabrication in the submillimeter range. Our approach included graft modification to prevent thrombotic events. Submillimeter arterial grafts harvested from the human placenta were decellularized and chemically crosslinked to heparin. Graft performance was evaluated using a microsurgical arteriovenous loop (AVL) model in Lewis rats. Specimens were evaluated through hematoxylin-eosin and CD31 staining of histological sections to analyze host cell immigration and vascular remodeling. Graft patency was determined 3 weeks after implantation using a vascular patency test, histology, and micro-computed tomography. A total of 14 human placenta submillimeter vessel grafts were successfully decellularized and implanted into AVLs in rats. An appropriate inner diameter to graft length ratio of 0.81 ± 0.16 mm to 7.72 ± 3.20 mm was achieved in all animals. Grafts were left in situ for a mean of 24 ± 4 days. Decellularized human placental grafts had an overall patency rate of 71% and elicited no apparent immunological responses. Histological staining revealed host cell immigration into the graft and re-endothelialization of the vessel luminal surface. This study demonstrates that decellularized vascular grafts from the human placenta have the potential to serve as super-microsurgical vascular replacements.

Same day discharge for robot-assisted radical prostatectomy: a prospective cohort study documenting an Australian approach

BACKGROUND

The introduction of robotic surgical systems has significantly impacted urological surgery, arguably more so than other surgical disciplines. The focus of our study was length of hospital stay - patients have traditionally been discharged day 1 post-robot-assisted radical prostatectomy (RARP), however, during the ongoing COVID-19 pandemic and consequential resource limitations, our centre has facilitated a cohort of same-day discharges with initial success.

METHODS

We conducted a prospective tertiary single-centre cohort study of a series of all patients (n = 28) - undergoing RARP between January and April 2021. All patients were considered for a day zero discharge pathway which consisted of strict inclusion criteria. At follow-up, each patient's perspective on their experience was assessed using a validated post-operative satisfaction questionnaire. Data were reviewed retrospectively for all those undergoing RARP over the study period, with day zero patients compared to overnight patients.

RESULTS

Overall, 28 patients 20 (71%) fulfilled the objective criteria for day zero discharge. Eleven patients (55%) agreed pre-operatively to day zero discharge and all were successfully discharged on the same day as their procedure. There was no statistically significant difference in age, BMI, ASA, Charlson score or disease volume. All patients indicated a high level of satisfaction with their procedure. Median time from completion of surgery to discharge was 426 min (7.1 h) in the day zero discharge cohort.

CONCLUSION

Day zero discharge for RARP appears to deliver high satisfaction, oncological and safety outcomes. Therefore, our study demonstrates early success with unsupported same-day discharge in carefully selected and pre-counselled patients.

Association of Peri-ictal MRI Abnormalities With Mortality, Antiseizure Medication Refractoriness, and Morbidity in Status Epilepticus

BACKGROUND AND OBJECTIVES

Status epilepticus (SE) is a life-threatening emergency requiring a prompt assessment of patient prognosis to guide management. MRI allows the identification of peri-ictal MRI abnormalities (PMAs) and provides insight into brain structural modifications induced by SE. However, little is known about the significance of PMA in SE prognosis. The aim of this study was to determine whether PMAs are associated with an increased mortality in SE and to establish the association between PMA and refractoriness to antiseizure medications, complications encountered, and induced morbidity.

METHODS

We conducted a retrospective observational cohort study including all eligible consecutive patients over 15 years old and hospitalized with SE at Bordeaux University Hospital (France) between January 2015 and December 2019. The primary end point was in-hospital mortality. A dedicated neuroradiologic reassessment was performed, together with a comprehensive medical review assessing baseline characteristics, in-hospital death, SE characterization, drug refractoriness, and following outcome in survivors.

RESULTS

Of 307 patients included, 79 (26%) showed PMA related to SE. Demographic, functional status at baseline and median delay between SE onset and MRI examination were similar in the PMA-positive and PMA-negative groups. In-hospital death occurred in 15% (45/307) patients and was significantly higher in the PMA-positive group (27%, 21/79 vs 11%, 24/228; p < 0.001). In multivariate analysis, the presence of PMA (odds ratio [OR] 2.86, 95% CI 1.02-8.18; p = 0.045), together with SE duration (OR 1.01, 95% CI 1.01-1.02; p = 0.007), older age at SE onset (OR 1.05, 95% CI 1.01-1.09; p = 0.013), preexisting ultimately fatal comorbidity (OR 4.01, 95% CI 1.56-10.6; p = 0.004), and acute lesional SE etiology (OR 3.74, 95% CI 1.45-10.2; p = 0.007) were independent predictors associated with in-hospital death. Patients with PMA had a higher risk of refractory SE (71 vs 33%, p < 0.001). Among survivors, delayed-onset epilepsy (40% vs 21%, p = 0.009) occurred more frequently in the PMA-positive group.

DISCUSSION

PMA-positive cases had a higher mortality rate in the largest cohort so far to assess the prognosis value of PMA in SE. As a noninvasive and easily available tool, PMA represents a promising structural biomarker for developing a personalized approach to prognostication in patients with SE receiving MRI.

Trial in progress: PREPARE—Exploring the activity of pseudoephedrine in treating retrograde ejaculation following retroperitoneal lymph node dissection (RPLND) in survivors of testicular cancer (TC)

TPS432

Background: Retrograde ejaculation is a known complication of RPLND occurring due to interruption of sympathetic nerve fibres intraoperatively. Whilst common immediately after surgery, the prevalence of persistent symptoms, and impact on health-related quality-of-life (HRQoL) in TC survivors is unknown. Whilst few effective treatments are available, alpha-sympathomimetics such as pseudoephedrine may form a viable treatment option due to effects on bladder neck constriction at sexual climax propagating antegrade ejaculation. Existing studies have shown pseudoephedrine may be helpful in individuals with retrograde ejaculation; however, these studies have only included a small number (n=5) of patients following RPLND. Methods: In a two-part, single-arm phase 2 clinical trial, participants with a history of TC receiving follow-up after RPLND at least >6 months prior will be invited to participate. In part A (ACTRN12622000537752), eligible participants complete questionnaires regarding survivorship issues including sexual function and fertility to explore the prevalence of retrograde ejaculation and HRQoL. Questionnaires include EORTC QLQ-C30, sexual function items from EORTC QLQ-TC26, Brief Male Sexual Function Inventory and tailored questions focusing on retrograde ejaculation. 15 out of a planned 50 participants (30%) have been enrolled and completed questionnaires. If retrograde ejaculation is reported, eligible participants are invited to enrol in Part B (ACTRN12622000542796), where if the participant has no contraindications to pseudoephedrine, nor are they receiving testosterone replacement and retrograde ejaculation is confirmed during screening, they receive a short course of pseudoephedrine hydrochloride. Pseudoephedrine will be given 60mg QID for one-day, followed by 60mg 4 hours and 1 hour prior to ejaculation to evaluate changes in ejaculation volume, sperm count within (any) antegrade ejaculate and within the post-ejaculatory urine. The primary endpoint is total sperm count in antegrade ejaculate of at least 39 million (5th centile) following treatment. We assumed that pseudoephedrine is ineffective if <10% of participants achieve a normal sperm count in antegrade ejaculate after treatment. Using an exact binomial power analysis for a one-sample proportion test, a sample size of 25 participants provides >80% power to detect 36% (9 out of 25) of participants achieving a normal sperm count against a reference proportion of 10% at the 0.05 significance level. 4 out of a planned 30 participants (16%) have been enrolled. All participants with retrograde ejaculation will be invited to an optional, semi-structured interview to further evaluate impact(s) of retrograde ejaculation on issues around sexual health, relationships, body image and masculinity. Clinical trial information: ACTRN12622000537752 , ACTRN12622000542796 .

Trial in progress: PRESTIGE—Primary retroperitoneal lymph node dissection (RPLND) for clinical stage II (CSII) testicular germ cell tumour (TGCT) and its impact on health-related quality of life (HRQoL) compared to chemotherapy or radiotherapy

TPS433

Background: As cure rates for patients with advanced TGCT improve, there is increasing focus on quality of survival. Increasingly, primary RPLND is being used as an alternative to chemotherapy (and radiotherapy) as primary treatment for selected individuals, due to the development of low morbidity surgical techniques (robot-assisted and extraperitoneal approaches), and recognition of acute and long-term toxicity of chemotherapy and radiotherapy. We hypothesise that primary RPLND compared to chemotherapy and radiotherapy will have less detrimental impact on HRQoL with comparable oncological outcomes. Methods: PRESTIGE is a prospective cohort study among adults with histologically confirmed advanced TGCT planned for primary RPLND, chemotherapy or radiotherapy. Eligible patients may have de novo advanced disease, or relapse within two- (NSGCT) or three-years (seminoma) following orchidectomy, without prior chemotherapy or radiotherapy (including adjuvant), and able to complete HRQoL questionnaires in English. See table for cohort-specific eligibility. Surgical approach (modality, template, adjuvant chemotherapy), chemotherapy regimen and radiotherapy dose will be administered at physician discretion and captured in Australia’s national multi-centre TGCT registry, iTestis, with clinical data in follow-up. Participants will complete HRQoL questionnaires focusing on physical, social, emotional, and functional domains commencing prior to treatment and continuing for 24 months. Questionnaires include EORTC QLQ-C30, EORTC QLQ-TC26, Brief Male Sexual Function Inventory and specific questions focusing on retrograde ejaculation and fertility. Patients undergoing RPLND will also have miR-371 evaluation pre-operatively and serially for 12 months after surgery. The primary outcome is change in EORTC QLQ-C30 global health status over 24 months for participants undergoing primary RPLND. Key secondary outcomes are changes in HRQoL, patterns of recurrence, surgical complications, retrograde ejaculation, and infertility. A sample size of 90 participants (30 for RPLND, 60 for chemotherapy) provides >80% power to detect a mean difference of 28% in global health status at 0.05 significance favouring RPLND. Up to 30 individuals receiving radiotherapy may also be enrolled. The first site was activated 4-Aug-22; 2 of 3 study sites are active and 5 out of a planned 120 (4%) participants have enrolled. [Table: see text]

Women's Understanding of Windows of Susceptibility and the Role of the Environment in Breast Cancer Risk

Emerging evidence suggests women who are exposed to harmful environmental exposures, especially during certain critical periods across the lifespan, may increase their breast cancer risk. Such windows of susceptibility (WoS) occur throughout a woman's lifetime, during which she is especially vulnerable to the effects of harmful environmental exposures. This interaction makes the reduction of harmful environmental toxicants during those time periods a priority for community health promotion. Communicating about environmental exposures and their impact on women's health requires an assessment of sense-making around, and understanding of, the link between breast cancer and the environment. To that end, focus groups were conducted to assess the themes that emerge when women make sense of (a) their own breast cancer risk, (b) the environment-cancer connection, and (c) WoS. Results provide insight into how women understand these issues which can inform messaging strategies focused on reducing harmful environmental exposures. Implications are discussed within the context of communication efforts tailored to educate women, particularly mothers with daughters in the prepubertal and pubertal WoS who are particularly vulnerable to harmful environmental exposures.

Design of an adaptive randomized clinical trial of intravenous citrulline for sickle cell pain crisis in the emergency department

Background

Vaso-occlusive pain crisis (VOC) is the most frequent cause for Emergency Department (ED) visits and hospital admissions for patients with sickle cell disease (SCD). Nitric oxide plays a critical role in the pathogenesis of vaso-occlusion. The amino acid, citrulline, is the main endothelial nitric oxide booster that offers the potential to ameliorate vaso-occlusion and decrease the risk of hospitalization.

Objective

In this two-part study, the goal of the first part is to determine the pharmacokinetic profile of intravenous (IV) l-citrulline and optimal dose for the second part of the study, which is to determine the efficacy and tolerability of the intervention in patients with SCD.

Design

A phase I/IIA open-label dose-finding study with subsequent double-blind, placebo-controlled, randomized Study of l-citrulline in children and adolescents with SCD presenting to the ED in VOC.

Methods

Part 1: Subjects experiencing VOC are enrolled in an open-label, ascending dose of IV l-citrulline to identify the optimum dose with endpoints of pharmacokinetic parameters, pain scores, reduction of opioid use, quality of life, proportion admitted to the hospital for treatment of pain, readmission rates, and assessment of adverse events. Part 2 of the trial is a double-blind, placebo-controlled adaptive "pick-the-winner" design to evaluate the efficacy and tolerability of IV l-citrulline in patients with SCD while receiving standard of care therapy for VOC.

Summary

This ED based sickle cell adaptive trial will determine the optimal dose for IV citrulline and whether the intervention improves outcome as a potential novel therapy for VOC in SCD.

Perfusion of the proximal scaphoid pole: correlation between preoperative ge-MRI and intraoperative findings

BACKGROUND

Gadolinium enhanced MRI (ge-MRI) is considered as gold standard for perfusion evaluation in case of scaphoid nonunion (SNU). However, its clinical value and specificity is still not clearly evaluated. This study compares preoperative ge-MRI-based perfusion assessment and intraoperative proximal pole (PP) perfusion after scaphoid reconstruction by vascularized bone grafts. In addition, the postoperative osseous consolidation (OC) was correlated to intraoperative perfusion findings.

METHODS

Between 08/2010 and 01/2020, 60 of 271 patients with scaphoid nonunion received a vascularized radius bone graft for reconstruction. Medical reports were checked for intra-op perfusion findings. Consolidation rate was assessed at mean follow-up of 3 months by CT evaluation. In 50 cases (83.2%), complete medical and radiological history could be obtained. Preoperative ge-MRI was reevaluated by a blinded radiologist for advanced analysis of sensitivity and specificity.

RESULTS

Preoperative ge-MRI (initial finding, IF) showed 23 avascular, 20 malperfused, and seven vital PP. Blinded radiological follow-up (second finding, SF) revealed 14 avascular, 28 malperfused, and 8 vital PP, with a concordance of 65.3% (n = 35). After correlation with the intra-op findings, a specificity of preoperative ge-MRI of 76.5% (IF) and 88.2 (SF), respectively, was revealed for exclusion of avitality. For detection of malperfusion, there was a sensitivity of 92.7% (IF) and 85.4% (SF), respectively. Complete OC was seen 12 weeks postoperatively in 37 (73.5%), partial OC in 9 (18.3%), and nonunion in 4 cases (8.2%) on CT-scans. Of the 41 malperfused/avascular PP, 31 (75.6%) progressed to complete and 6 (14.6%) to partial (at least 2 adjacent CT-layers of 2 mm) OC, with 4 nonunions.

CONCLUSION

The sensitivity and specificity of ge-MRI for detection/ exclusion of malperfusion/avitality of the PP was lower than expected. Therewith, the intraoperative assessment of PP perfusion regains a high value in decision-making for the appropriate graft. We recommend preservation of the dorsal radial vascular plexus initially until the vascularity of the proximal pole has been estimated. Patient education for all contingencies and retraction options should be obtained.

Photoelectrochemical water oxidation by a MOF/semiconductor composite

Herein, we report the development of a MOF-semiconductor composite film active for water oxidation at a thermodynamic underpotential.

Assessment of Two Advanced Aluminium-Based Metal Matrix Composites for Application to High Energy Physics Detectors

The Outer Tracker of the Compact Muon Solenoid (CMS), one of the large experiments at the CERN Large Hadron Collider, will consist of about 13,200 modules, each built up of two silicon sensors. The modules and support structures include thousands of parts that contribute to positioning and cooling the sensors during operation at -30 °C. These parts should be low mass while featuring high thermal conductivity, stiffness and strength. Their thermal expansion coefficient should match that of silicon to avoid deformations during cooling cycles. Due to their unique thermal and mechanical properties, aluminium-carbon fibre (Al/C_f) Metal Matrix Composites are the material of choice to produce such light and stable thermal management components for High Energy Physics detectors. For the CMS Outer Tracker, about 500,000 cm³ of Al/C_f raw material will be required to be produced through a reliable process to guarantee consistent properties throughout parts manufacturing. Two Al/C_f production routes are currently considered: liquid casting by gas-pressure infiltration and a powder metallurgy process based on continuous semi-liquid phase sintering. The dimensional stability of the resulting material is of paramount importance. Irreversible change of shape may be induced by moisture adsorption and the onset of galvanic corrosion at the discontinuous interfaces between C_f and Al. This paper presents the results of an extensive investigation through Computed Microtomography, direct microscopical investigations, analysis of the interfaces and metrology measurements aimed at comparing and interpreting the response to different environments of the respective products. The results obtained confirm the suitability of the two investigated Al/Cf MMCs for application to components of the CMS Outer Tracker, requiring tight geometrical control and microstructural stability over time. However, for PM parts sintered through the semi-liquid phase process, a multilayered protective noble metal coating is necessary the make them impervious to moisture, allowing dimensional stability to be guaranteed and the onset of corrosion phenomena to be avoided, while the product obtained by gas-pressure infiltration has shown less sensitive even to extreme temperature-humidity cycles and may be used uncoated.

Intraarticular steroids as DMARD-sparing agents for juvenile idiopathic arthritis flares: Analysis of the Childhood Arthritis and Rheumatology Research Alliance Registry

BACKGROUND

Children with juvenile idiopathic arthritis (JIA) who achieve a drug free remission often experience a flare of their disease requiring either intraarticular steroids (IAS) or systemic treatment with disease modifying anti-rheumatic drugs (DMARDs). IAS offer an opportunity to recapture disease control and avoid exposure to side effects from systemic immunosuppression. We examined a cohort of patients treated with IAS after drug free remission and report the probability of restarting systemic treatment within 12 months.

METHODS

We analyzed a cohort of patients from the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry who received IAS for a flare after a period of drug free remission. Historical factors and clinical characteristics and of the patients including data obtained at the time of treatment were analyzed.

RESULTS

We identified 46 patients who met the inclusion criteria. Of those with follow up data available 49% had restarted systemic treatment 6 months after IAS injection and 70% had restarted systemic treatment at 12 months. The proportion of patients with prior use of a biologic DMARD was the only factor that differed between patients who restarted systemic treatment those who did not, both at 6 months (79% vs 35%, p < 0.01) and 12 months (81% vs 33%, p < 0.05).

CONCLUSION

While IAS are an option for all patients who flare after drug free remission, it may not prevent the need to restart systemic treatment. Prior use of a biologic DMARD may predict lack of success for IAS. Those who previously received methotrexate only, on the other hand, are excellent candidates for IAS.

Objective Burn Scar Assessment in Clinical Practice Using the Cutometer©: Introduction and Validation of a Standardized Measurement Protocol

An objective burn scar assessment is essential to informed therapeutic decision-making and to monitor scar development over time. However, widely employed scar rating scales show poor inter-rater reliability. For this study we developed a standardized measurement protocol for the Cutometer© applicable for objective burn scar assessment in everyday clinical practice. We developed a measurement protocol for the Cutometer© MPA 580 including a scar site relocation technique based on anatomical landmarks. The protocol emerged through several steps: Identifying key factors for valid and reliable measurements, preliminary testing, specification of technical details, refining the protocol and final testing. Consecutively, the protocol was validated for inter-rater reliability by assessing 34 burn scars in 17 patients by four clinicians and computing an Intra-class Correlation Coefficient (ICC). Parameter R0, representing scar pliability, was identified as the best suited output parameter yielding excellent inter-rater reliability for average measures (ICC 0.92 [95% CI 0.86; 0.96]) and acceptable reliability for single measures (ICC: 0.74 [0.61; 0.84]). The pressure applied on the measuring probe was identified as an influential confounding factor for reliable measurements. Rater gender did not influence reliability of measurements. The introduced standardized measurement protocol for the Cutometer© MPA 580 enables an objective and reliable burn scar assessment for clinical as well as research purposes.

Microvascular dysfunction is associated with impaired myocardial work in obstructive and nonobstructive hypertrophic cardiomyopathy: a multimodality approach

Introduction

Myocardial work is a dynamic non-invasive method for assessing myocardial deformation. Microvascular dysfunction is a hallmark of hypertrophic cardiomyopathy (HCM). We hypothesized that there is an association between impaired myocardial work, evaluated by echocardiography, and left ventricular (LV) ischemia, detected by cardiac magnetic resonance (CMR).

Methods

Prospective assessment of HCM patients' (P) myocardial strain parameters with 2D speckle-tracking echocardiography. All P underwent CMR protocol (1.5-T) for the analysis of stress perfusion and late gadolinium enhancement (LGE). Perfusion defects were quantified as burden of ischemia (% of LV mass). Results were stratified according to obstructive (oHCM) and nonobstructive (nHCM) HCM as well as according to the presence of significant replacement fibrosis (LGE of ≥15% or &lt;15% of LV mass). Multivariate regression analyses were used to explore the relation between myocardial work and the burden of ischemia.

Results

75 P with HCM (63% male, age 55±15 years), 61% with asymmetric septal LVH, 29% with apical LVH, 8% with concentric LVH and 28% exhibiting LV outflow tract obstruction (mean maximal LVOT gradient of 89±60 mmHg). Perfusion defects were found in 68 P (90.7%), with a mean of 22.5±16.9% of LV mass and 29 P (38.7%) had LGE ≥15% of LV mass.

A lower global work index (GWI) significantly correlated with higher burden of myocardial perfusion defects (r=−0.520, β-estimate −0.019, 95% CI −0.028 to −0.010, p&lt;0.001). Likewise, impaired values of global work efficiency (GWE) were linked to higher percentage of hypoperfusion (r=−0.477, β-estimate −0.713, 95% CI −1.250 to −0.176, p&lt;0.001). Moreover, impaired global constructive work (GCW) (r=−0.519, β-estimate −0.021, 95% CI −0.030 to −0.013, p&lt;0.001) and a higher global wasted work (GWW) (r=0.280, p=0.017) were associated with a higher burden of perfusion defects (Figure 1).

GWI showed a higher correlation with perfusion defects in oHCM P (r=−0.518, p=0.019) vs. nHCM P (r=−0.492, p&lt;0.001), and the same was also found with GWE (oHCM: r=−0.591, p=0.006 vs. nHCM: r=−0.317, p=0.022) (Figure 2A). Furthermore, GCW showed a slightly higher correlation with hypoperfusion in oHCM P (r=−0.564, p=0.010) vs. nHCM P (r=−0.520, p&lt;0.001). There was no significant difference between oHCM and nHCM P regarding GWW.

In P with LGE ≥15%, GWI showed a better correlation with perfusion defects (r=−0.489, p=0.007) vs. P with LGE of &lt;15% (r=−0.369, p=0.007). Moreover, GCW showed a higher correlation with hypoperfusion in P with LGE ≥15% (r=−0.455, p=0.013) comparing with P with LGE &lt;15% LV mass (r=−0.359, p=0.019) (Figure 2B). No difference was found regarding GWE and GWW according to LGE burden.

Conclusion

In our cohort of P with HCM, impaired GWI, GWE and GCW and a higher GWW were significantly correlated with the presence of myocardial ischemia in CMR. This correlation was greater in P with oHCM and in P with LGE of ≥15% of LV mass.

Funding Acknowledgement

Type of funding sources: None.

OS01.7.A Detection of methylation-based prognostic signatures in liquid biopsy specimens from patients with meningiomas

Background

Detection of distinct epigenetic biomarkers in circulating cell-free DNA (cfDNA) of liquid biopsy (LB) specimens (e.g. blood) fosters opportunity for prognostication of central nervous system (CNS) tumors and has not been thoroughly explored in patients with meningiomas.

Material and Methods

We profiled the cfDNA methylome (EPIC array) in serum specimens from patients with meningiomas (MNG; n= 63) and harnessed internal and external meningioma tissue methylome data with reported follow up (n=48). To predict recurrence risk (RR), we consolidated a tissue cohort with at least 5 years of follow up and divided them into confirmed recurrence (CR; either reported progressive disease in post-surgical imaging, or additional resections following initial surgery) and confirmed no-recurrence (CNR: no confirmed disease progression w/in at least 5-years of follow-up). Then through application of an iterative process consisting of multiple tissue- and serum-based supervised analyses, we identified risk-specific methylation markers with serum specific features which, when inputted into a random forest algorithm allowed for segregation of both tumor tissue and liquid biopsy specimens according to recurrence risk. We estimated immune cell composition using MethylCIBERSORT, where a reference methylome atlas of chosen immune cell types was utilized to deconvolute the MNG samples.

Results

The resulting recurrence risk classifier demonstrated an appreciable predictive power in classifying samples as high or low recurrence risk across the tumor tissue cohort (ACC: 87.5%, CUI+: 85.2%). When compared to another classifier, our model demonstrated statistically significant agreement across primary meningioma samples (κ=0.269, p=0.002), and more accurately predicted samples to recur across an expanded time window (time to recurrence &gt;5yrs). Across resulting liquid biopsy classifications, recurrence risk subgroups were analogous with reported risk factors, including WHO grade, extent of resection, and tumor location. Recurrence risk subgroups (high and low) also demonstrated differential estimated immune cell contributions, with low-risk samples exhibiting a “hot” profile, or enrichment of B-Cells, CD56- and CD4 T-Cells, and natural killer cells. Notably, the estimated neutrophil to lymphocyte ratio, previously purported to be relevant to tumor prognosis, was appreciably higher for those meningioma samples with the highest recurrence risk.

Conclusion

DNA methylation markers identified in the serum are suitable for the development of machine learning-based models which present high predictive power to prognosticate patients with meningioma and estimate a differential immune profile across recurrence risk groups. After validation in an external cohort, this noninvasive approach may improve the presurgical therapeutic management of patients with meningiomas.

OS08.3.A Distinct systemic and tumor microenvironment immune landscapes discriminate across sellar tumor types and controls through a methylation-based deconvolution method

Background

Systemic (Sys) and tumor microenvironment (TME) immune milieus play a pivotal role in tumor development, outcome and immunotherapy response predictions across a variety of central nervous system tumors. Genome-wide methylation profiling can reliably discriminate and estimate immune cell proportions present in the blood and within the tumor and has not been reported across sellar tumor types (STT).

Material and Methods

We estimated cell composition in liquid biopsy (LB, serum/plasma) and tissue specimens from 42 STT collections (i.e., pituitary neuroendocrine tumors [PitNETs; n=37] and craniopharyngiomas [CP; n=5]), and 26 nontumor controls (LB: 11; Tissue: 15) using MethylCIBERSORT, a methylation-based deconvolution algorithm and established immune cell signatures as reference. LB methylation was profiled with EPIC array. Correlations between estimated cell proportions across sample sources were explored (Spearman). Immune cell proportion hierarchical k-means clustering was performed across tissue and LB specimens. Similarly, mean comparisons between and across sample types and subgroups of interest were performed [Non-parametric Kruskal-Wallis, Wilcoxon rank-sum tests; p&lt;0.05].

Results

We identified three immune-clusters across tissue specimens which distinguished controls (k3-cluster) from sellar tumor specimens (k1- and k2- clusters), primarily attributable to differential B-cell and monocyte proportions. Interestingly, a subset of PitNET and CP, belonging to the k2-cluster, presented a distinct immune profile compared to their K1-sellar tumor counterparts. Analysis of plasma-derived immune clusters revealed that PitNETs were distributed across four distinct immune patterns and CP clustered together with controls and a PitNET subset. One of the PitNET clusters was enriched with patients that died during follow-up and presented an enrichment of CD4-(including the regulatory subtype), CD8 and CD56-T and depletion of natural killer cells. Differences across serum- and tissue-derived clusters were present but less prominent than their plasma counterparts. No correlation between immune cell proportions across other clinicopathological features within each tumor type (sex, age, histotypes, invasion etc) was observed.

Conclusion

Our results suggest that PitNETs are characterized by differential TME and systemic immune subtypes which also distinguish these tumors from CP and controls. Additionally, distinct systemic immune composition between tissue and LB sources, more readily observed in plasma, suggest that the systemic response to the presence of the tumor is distinct from the immune response noted in the TME. Tumor immune subtyping may allow the stratification of STT according to immunotherapy response vulnerabilities.