Complications and outcomes following inguinal lymphadenectomy for malignant melanoma in an Asian population

Purpose

Melanoma is a potentially fatal cutaneous malignancy and regional lymph node (LN) metastases are the most important predictors of mortality. This study aimed to analyze clinical features and risk factors of complications associated with inguinal LN dissection (LND) to establish treatment protocols.

Methods

This single-center retrospective study (2000 to 2018) consisted of patients who underwent inguinal area sentinel LN biopsy (SLNB) or LND due to malignant melanoma. Risk factors and outcomes were analyzed.

Results

One hundred patients underwent SLNB alone (n=67; patients with negative SLNB), complete LND (CLND) after positive SLNB (n=19), or radical LND without SLNB (n=14). Five-year overall survival and disease-free survival rates among these groups were 87.3%, 57.4%, and 61.9%, and 59.0%, 22.7%, and 28.1%, respectively. The complication rate in the SLNB alone group was lower than the other groups (22.4% vs. 47.4% and 35.7%, respectively; P=0.048). Seroma was the most common complication in the SLNB alone group (15.0%); lymphedema was most common in the CLND after SLNB group (21.1%). Multivariate analysis of risk factors for postoperative complications found the hazard ratio for body mass index >28 kg/m² was 4.376 (95% confidence interval [CI], 1.243-15.401; P=0.022). The hazard ratio for LND (including CLND after SLNB and radical LND without SLNB) was 3.263 (95% CI, 1.248-8.529; P=0.016).

Conclusion

Inguinal LND is a higher risk procedure compared to SLNB and other sites for postoperative complications, irrespective of meticulous surgical techniques. More studies are needed to establish treatment protocols (e.g., observation vs. CLND after a positive SLNB result) and the risks and benefits in Asian populations.

Economic evaluation of adjuvant trastuzumab emtansine in patients with HER2-positive early breast cancer and residual invasive disease after neoadjuvant taxane and trastuzumab-based treatment in Canada

Background

In the katherine trial, adjuvant trastuzumab emtansine [T-DM1, Kadcyla (Genentech, South San Francisco, CA, U.S.A.)], compared with trastuzumab, significantly reduced the risk of recurrence or death by 50% (unstratified hazard ratio: 0.50; 95% confidence interval: 0.39 to 0.64; p < 0.0001) in patients with her2-positive early breast cancer (ebc) and residual invasive disease after neoadjuvant systemic treatment. A cost-utility evaluation, with probabilistic analyses, was conducted to examine the incremental cost per quality-adjusted life-year (qaly) gained associated with T-DM1 relative to trastuzumab, given the higher per-cycle cost of T-DM1.

Methods

A Markov model comprising a number of health states was used to examine clinical and economic outcomes over a lifetime horizon from the Canadian public payer perspective. Patients entered the model in the invasive disease-free survival (idfs) state, where they received either T-DM1 or trastuzumab. Transition probabilities between the health states were derived from the katherine trial, Canadian life tables, and published literature from other relevant clinical trials (emilia, cleopatra, and M77001). Resource use, costs, and utilities were derived from katherine, other clinical trials, published literature, provincial fee schedules, and clinical expert opinion. Sensitivity analyses were conducted for key assumptions and model parameters.

Results

Compared with trastuzumab, adjuvant T-DM1 was associated with a cost savings of $8,300 per patient and a 2.16 incremental qaly gain; thus T-DM1 dominated trastuzumab. Scenario analyses yielded similar results, with T-DM1 dominating trastuzumab or producing highly favourable incremental cost-utility ratios of less than $10,000 per qaly.

Conclusions

Adjuvant T-DM1 monotherapy is a cost-effective strategy compared with trastuzumab alone in the treatment of patients with her2-positive ebc and residual invasive disease after neoadjuvant systemic treatment.

Complete transmural epicardial ablation reduces organized areas in atrial fibrillation

Background

The surgical maze is suggested to be effective in persistent atrial fibrillation (AF) by reducing the area for fibrillatory wavelets. However, the mechanism for recurrence and next treatment steps are unclear.

Purpose

We set out to evaluate the impact of complete transmural epicardial maze lesion sets on the extent atrial organization using novel analyses of wide-area recordings of AF.

Methods

19 patients (age 50.9±12.0, 78% male) underwent maze followed by endocardial mapping of AF with a 64-pole basket catheter. Block across roof, floor, and pulmonary vein lesions sets was assessed by high-density voltage mapping and organized zones of AF were assessed by panoramic recordings. Total organized area and mean area of the dominant site were evaluated using automated custom scripts.

Results

Patients had 3.2±0.9 organized regions in 1 minute of LA recordings. A 54 yo F showed residual conduction to the posterior wall from the roof (purple, Fig. 1A) and a figure-of-8 propagation pattern during AF (arrows, fig B) which terminated with localized ablation (yellow lesions, Fig. 1A, red X, Fig. 1B). Overall, patients with complete block on epicardial lesion set had smaller areas of organization (13.7±8% vs. 45.7±32% of mapped areas, p=0.029) vs. those with gaps. The average size of the dominant area was smaller with complete transmural lines than with gaps (5.7±3% vs. 15.9±10%, p=0.033) (Fig. 1C).

Conclusion

These results show that complete transmural lesion sets constrain the critical mass available for AF, with smaller resulting organized zones. Future studies that quantify how partitioning the atrial surface affects AF may help personalize lesion sets after maze.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): NIH NRSA F32 United States

Co-designed annular binary phase masks for depth-of-field extension in single-molecule localization microscopy

Single-molecule localization microscopy has become a prominent approach to study structural and dynamic arrangements of nanometric objects well beyond the diffraction limit. To maximize localization precision, high numerical aperture objectives must be used; however, this inherently strongly limits the depth-of-field (DoF) of the microscope images. In this work, we present a framework inspired by "optical co-design" to optimize and benchmark phase masks, which, when placed in the exit pupil of the microscope objective, can extend the DoF in the realistic context of single fluorescent molecule detection. Using the Cramér-Rao bound (CRB) on localization accuracy as a criterion, we optimize annular binary phase masks for various DoF ranges, compare them to Incoherently Partitioned Pupil masks and show that they significantly extend the DoF of single-molecule localization microscopes. In particular we propose different designs including a simple and easy-to-realize two-ring binary mask to extend the DoF. Moreover, we demonstrate that a simple maximum likelihood-based localization algorithm can reach the localization accuracy predicted by the CRB. The framework developed in this paper is based on an explicit and general information theoretic criterion, and can thus be used as an engineering tool to optimize and compare any type of DoF-enhancing phase mask in high resolution microscopy on a quantitative basis.

Synucleinopathy alters nanoscale organization and diffusion in the brain extracellular space through hyaluronan remodeling

In recent years, exploration of the brain extracellular space (ECS) has made remarkable progress, including nanoscopic characterizations. However, whether ECS precise conformation is altered during brain pathology remains unknown. Here we study the nanoscale organization of pathological ECS in adult mice under degenerative conditions. Using electron microscopy in cryofixed tissue and single nanotube tracking in live brain slices combined with super-resolution imaging analysis, we find enlarged ECS dimensions and increased nanoscale diffusion after α-synuclein-induced neurodegeneration. These animals display a degraded hyaluronan matrix in areas close to reactive microglia. Furthermore, experimental hyaluronan depletion in vivo reduces dopaminergic cell loss and α-synuclein load, induces microgliosis and increases ECS diffusivity, highlighting hyaluronan as diffusional barrier and local tissue organizer. These findings demonstrate the interplay of ECS, extracellular matrix and glia in pathology, unraveling ECS features relevant for the α-synuclein propagation hypothesis and suggesting matrix manipulation as a disease-modifying strategy.

The nanoscale organisation of the brain extracellular space can be studied in vivo. Here, the authors investigate how it changes in response to α-synuclein pathology, and identify interactions between microglia and the extracellular matrix.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.