Postoperative surveillance after surgery for colorectal liver metastasis: a cross-sectional study

INTRODUCTION

Colorectal liver metastases (CRLM) are associated with a high recurrence rate after surgery. There is paucity of high-quality evidence regarding the nature and overall benefit of surveillance after hepatectomy for CRLM. As part of a broader programme of research, this study aimed to assess current strategies for surveillance after liver resection for CRLM and outline surgeons' opinions regarding the benefit of postoperative surveillance.

METHODS

An online survey was sent to clinicians performing surgery for CRLM at tertiary hepatobiliary centres in the UK.

RESULTS

There were responses from a total of 23 centres (88% response rate); 15/23 centres used standardised surveillance protocols for all patients. Most centres followed patients up at six months, but there is variation in postoperative surveillance at 3, 9, 18 and beyond 60 months. Patient comorbidities, indeterminate findings on imaging, margin status and assessment of recurrence risk were identified as the major factors influencing personalised surveillance strategies. There was clear clinician equipoise regarding the costs and benefits of surveillance.

CONCLUSION

There is heterogeneity in postoperative follow-up for CRLM in the UK. High-quality prospective studies and randomised trials are necessary to elucidate the value of postoperative surveillance and identify optimal follow-up strategies.

Carbonate treated coffee powder (CTCP) for selective sorption of Pu4+ over Am3+, Np4+, NpO22+, and PuO22+ from aqueous acidic solution: Investigation on mechanism, kinetics, thermodynamics, stripping and radiolytic stability

An attempt was made for understanding the sorption behaviour of different actinide ions Pu⁴⁺, PuO₂²⁺, Am³⁺, Np⁴⁺, and NpO₂²⁺ on carbonate treated exhausted coffee powder (CTCP). Very efficient sorption of Pu⁴⁺ over other actinide ions from aqueous acidic medium was observed. Almost 4 h were required for achieving equilibrium. Experimental results for Pu⁺⁴ were fitted into different sorption isotherm model: Langmuir isotherm, Freundlich isotherm, D.R, isotherm and Temkin isotherm. Based on the linear regression, it was found that, Freundlich isotherm was predominantly operative. Pseudo 2nd order kinetics was found to be effective for the sorption of Pu⁺⁴. More than 80 % of loaded Pu⁴⁺ was found to desorb by 0.25 M oxalic acid solution. CTCP exhibited relatively good radiation stability. Sorption of Pu⁺⁴ on CTCP was exothermic, and spontaneous in nature. The sorption process was simple, cost effective and environmentally benign, as it did not involve any sophisticated, multi-step, sorbent synthesis.

Fractal characterizations of MeV ion treated CaF2 thin films

We present the morphological evolution and fractal characterizations of CaF₂ thin-film surfaces modified by bombardment with 100 MeV Au⁺⁸ ions at various fluences. Atomic force microscopy (AFM) combined with line profile and two-dimensional power spectral density (2D-PSD) analysis was utilized to investigate the evolution of surface morphology as a function of fluence. The AFM images were utilized to investigate the relationship between fractal dimension, roughness exponent, lateral correlation length, and ion fluence. The surface erosion owing to sputtering was depicted using Rutherford backscattering spectrometry. The structural characteristics' dependency on fluence was explored with the help of glancing angle x-ray diffraction measurements on virgin and irradiated samples. Tensile stress calculated using a peak shift in the glancing angle x-ray diffractogram showed an increase in tensile stress with fluence that caused the surface to crack after the fracture strength of the surface was crossed. 2D-PSD analysis signified the role of sputtering over surface diffusion for the observed surface modifications. Fractal dimensions first increased and then decreased with ion fluence. The lateral correlation length decreased, while the roughness exponent increased with fluence after the threshold value.

Giant Orbital Anisotropy with Strong Spin-Orbit Coupling Established at the Pseudomorphic Interface of the Co/Pd Superlattice

Orbital anisotropy at interfaces in magnetic heterostructures has been key to pioneering spin-orbit-related phenomena. However, modulating the interface's electronic structure to make it abnormally asymmetric has been challenging because of lack of appropriate methods. Here, the authors report that low-energy proton irradiation achieves a strong level of inversion asymmetry and unusual strain at interfaces in [Co/Pd] superlattices through nondestructive, selective removal of oxygen from Co₃ O₄ /Pd superlattices during irradiation. Structural investigations corroborate that progressive reduction of Co₃ O₄ into Co establishes pseudomorphic growth with sharp interfaces and atypically large tensile stress. The normal component of orbital to spin magnetic moment at the interface is the largest among those observed in layered Co systems, which is associated with giant orbital anisotropy theoretically confirmed, and resulting very large interfacial magnetic anisotropy is observed. All results attribute not only to giant orbital anisotropy but to enhanced interfacial spin-orbit coupling owing to the pseudomorphic nature at the interface. They are strongly supported by the observation of reversal of polarity of temperature-dependent Anomalous Hall signal, a signature of Berry phase. This work suggests that establishing both giant orbital anisotropy and strong spin-orbit coupling at the interface is key to exploring spintronic devices with new functionalities.

1285 Reporting of Robotic Pancreaticoduodenectomy As A Surgical Innovation: Systematic Review and Narrative Synthesis

Aim

Pancreaticoduodenectomy (PD) is most commonly performed using open surgical techniques. Minimal access approaches have reduced the morbidity of many types of surgery, however technical limitations have hindered the widespread adoption of laparoscopic methods for PD. There has been increasing use of surgical robots to facilitate a minimal access approach, motivated by improved visualisation, ergonomics and dexterity compared to standard laparoscopic methods. Methods for the safe introduction of novel techniques are lacking, and the way in which surgical innovations are reported may affect adoption into clinical practice. The aim of this study is to understand how robotic PD has been reported as a surgical innovation.

Method

A systematic review is being conducted by the trainee led RoboSurg Collaborative. A literature search was performed to identify primary research reporting outcomes of robotic PD. Articles are being screened in duplicate by title and abstract, then by full text review. The following data will be extracted: study methodology and rationale; centre, surgeons and patient details; governance and ethical considerations; learning curves; details of the intervention, including modifications; and how outcomes were reported, including use of core outcome sets. The data will be analysed using a narrative synthesis method.

Results

The search identified 1305 articles reporting on robotic pancreas surgery. An interim report of progress will be presented.

Conclusions

A rich narrative synthesis will enable innovators to understand how robotic PD has been reported. This will encourage transparent, methodical, and meaningful reporting of robotic PD, increasing the quality of clinical evidence.

558 Summarising the Reporting of Outcomes in Studies of Robot Assisted Cholecystectomy: A Systematic Review

Background

Robot-assisted cholecystectomy (RC) has seen increasing adoption into clinical practice despite a lack of evidence to demonstrate superiority over conventional methods. Consistency in outcome selection, definition and reporting between studies is required for effective evidence synthesis and to minimise research waste. The aim of this study was to conduct an in-depth analysis of the outcomes reported in studies of RC. This work will inform the need for a core outcome set (COS).

Method

Systematic searches identified all published studies reporting RC, from inception to February 2020. Outcomes reported in each manuscript were recorded verbatim and categorised into domains. All outcomes were coded in duplicate. Where reported, the follow up period of each study was documented.

Results

Of 1425 abstracts screened, ninety studies met the criteria for inclusion. A total of 878 outcomes were reported. Each study included a median of 8 outcomes (range 3-26). Outcome selection was heterogeneous, with those relating to technical/operative factors (n = 383, 88 studies), complications (n = 245, 81 studies) and health economics (n = 139, 72 studies) used most frequently. No single outcome, or outcome domain, was reported in all studies. Only 30 studies reported a follow-up period, which ranged from 14 days to 46 months. In thirteen, the follow-up was for less than or equal to one month.

Conclusions

We identified significant heterogeneity in the selection and reporting of outcomes in studies of RC and support calls for standardisation and development of a COS.

Enhanced Spin-to-Charge Conversion Efficiency in Ultrathin Bi2Se3 Observed by Spintronic Terahertz Spectroscopy

Owing to their remarkable spin-charge conversion (SCC) efficiency, topological insulators (TIs) are the most attractive candidates for spin-orbit torque generators. The simple method of enhancing SCC efficiency is to reduce the thickness of TI films to minimize the trivial bulk contribution. However, when the thickness reaches the ultrathin regime, the SCC efficiency decreases owing to intersurface hybridization. To overcome these contrary effects, we induced dehybridization of the ultrathin TI film by breaking the inversion symmetry between surfaces. For the TI film grown on an oxygen-deficient transition-metal oxide, the unbonded transition-metal d-orbitals affected only the bottom surface, resulting in asymmetric surface band structures. Spintronic terahertz emission spectroscopy, an emerging tool for investigating the SCC characteristics, revealed that the resulting SCC efficiency in symmetry-broken ultrathin Bi₂Se₃ was enhanced by up to ∼2.4 times.

A proposed "Radiological Evaluation Score for Bone Tumors" (REST): An objective system for assessment of a radiograph in patients with suspected bone tumor

BACKGROUND

Although radiographs have been widely used in the evaluation of patients with suspected bone tumors, the lack of an objective radiological assessment method leads to a challenge in reaching correct diagnosis. The study aimed to propose a Radiological Evaluation Score for Bone Tumors (REST) which includes eight radiological factors [characteristics, content, cortical breach, distinctiveness, distribution, periosteal reaction, fracture, and soft tissue swelling] to form a single score along with its validation by multidisciplinary observers.

METHODS

We reviewed the radiographs of 100 patients with a primary bone tumor which were selected at random from the database between January 2017 and January 2019 of a tertiary cancer center. Four reviewers (two orthopedic oncologists and two surgical oncologists) independently assessed the radiographs, based on the reporting system of REST. We constituted two groups according to the probable diagnosis of bone tumor (suspected benign tumor and suspected malignant tumor).

RESULTS

The mean score in the suspected benign tumor group was 1.1 (range 0-3, 95% CI 0.8-1.3) and in malignant tumor group was 6.1 (range 2-8, 95% CI 5.8-6.4). A receiver operator characteristic (ROC) curve for REST was with a cutoff of 3.5, with the most diagnostic value area under curve (AUC) of 0.99. The sensitivity was 98% and specificity was 100% with a positive predictive value of 100% and a negative predictive value of 98%. The inter-observer correlation coefficient was 0.985 (p value < 0.05), and Fleiss kappa value for the prediction of the benign or malignant lesion was 0.97 (p value < 0.05). The characteristics and content of tumor, cortical erosion, distinctiveness, distribution, periosteal reaction, and soft tissue mass had a significant correlation with the aggressiveness of bone lesion p value < 0.05.

CONCLUSIONS

The Radiological Evaluation Score for Bone Tumors (REST) is a structured reporting and objective method for the assessment of radiographs in patients with suspected bone tumors. This method is a reliable and helpful tool for clinicians in their outdoor patient department to differentiate a radiograph of a suspected benign tumor from a malignant bone tumor.

A proposed ''A to Z RAM (Radiograph Assessment Method)'' for triage of patients with a suspected bone tumour

INTRODUCTION

We propose a ''A to Z RAM (Radiograph Assessment Method)'' for evaluation of Radiograph of patients with a suspected bone tumour.

METHODS

In the current study, ten radiological features with letters 'A, B, C, D, E, F and Z' were used and which included the age of the patient, involved part of the bone, characteristics, content, distinctiveness, the exterior of the bone, fracture, and zone of transition. Four independent observers (orthopaedic oncologists and surgical oncologists) evaluated a set of 30 radiographs of bone tumour selected at random from our hospital database based on A to Z RAM. We classified the lesions into two groups according to the traffic signal system; Green (suspected benign lesion) and Red (suspected malignant lesion).

RESULTS

There were 18 (60%) benign bone lesions and 12 (40%) malignant lesions in the current study. 91.6% of malignant tumours and 88.8% of the benign tumours were identified correctly by the four observers. The inter-observer variability with Fleiss kappa was 0.884 (95% CI 0.7-1.03 p-value < 0.05), suggestive of agreement not by chance. These radiographs were again reassessed by the four observers after 3 months. The interobserver variability by Fleiss kappa was 1.0 (95% CI 0.8-1.1) suggesting complete agreement amongst the observers. Both orthopaedic oncologists had intra-observer kappa as 1.0 each and both surgical oncologists had 0.795 and 0.930 respectively.

CONCLUSION

The proposed A to Z RAM is an easy to use and reproducible method for reviewing radiographs in the out-patient department along with clinical findings for better management of patients with suspected bone lesions. The A to Z RAM can be a medical triage tool and subdivide bone lesions into two subgroups i.e. suspected benign lesion with a suggestion of further investigations with MRI and biopsy and suspected malignant lesion with a suggestion of MRI or early referral to a tertiary cancer center with expertise in orthopaedic oncology.

IMPLICATIONS FOR PRACTICE

The A to Z RAM (Radiologic Assessment Method) is a reproducible method for reviewing radiographs in the out-patient department and can be an aid for better management of patients. A to Z RAM is useful as a medical triage system, subdividing patients according to the probable diagnosis into a suspected benign lesion and suspected malignant lesion.

Incisional hernia formation in hepatobiliary surgery using transverse and hybrid incisions: a systematic review and meta-analysis

INTRODUCTION

Evidence suggests that midline incisions should be closed with the small-bite technique to reduce IH formation. No recommendations exist for the closure of transverse incisions used in hepatobiliary surgery. This work systematically summarises rates of IH formation and associated technical factors for these transverse incisions.

METHODS

A systematic search was undertaken. Studies describing the incidence of IH were included. Incisions were classified as transverse (two incision types) or hybrid (transverse with midline extension, comprising five incision types). The primary outcome measure was the pooled proportion of IH. Subgroup analysis based on minimum follow-up of two years and a priori definition of IH with clinical and radiological diagnosis was undertaken.

FINDINGS

Thirteen studies were identified and included 5,427 patients; 1,427 patients (26.3%) underwent surgery for benign conditions, 3,465 (63.8%) for malignancy and 535 (9.9%) for conditions that were not stated or classified as 'other'. The pooled incidence of IH was 6.0% (2.0-10.0%) at a weighted mean follow-up of 17.5 months in the transverse group, compared with 15.0% (11.0-19.0%) at a weighted mean follow-up of 42.0 months in the hybrid group (p = 0.045). Subgroup analysis did not demonstrate a statistical difference in IH formation between the hybrid versus transverse groups.

CONCLUSION

Owing to the limitations in study design and heterogeneity, there is limited evidence to guide incision choice and methods of closure in hepatopancreatobiliary surgery. There is an urgent need for a high-quality prospective cohort study to understand the techniques used and their outcomes, to inform future research.

Safety and tolerability of injectable Rilpivirine LA in HPTN 076: A phase 2 HIV pre-exposure prophylaxis study in women

BACKGROUND

Daily oral TDF/FTC is protective against HIV infection when used for pre-exposure prophylaxis (PrEP). However, daily adherence to oral PrEP is difficult for many; therefore, finding alternative PrEP strategies remains a priority. HPTN 076 evaluated the long-acting injectable form of rilpivirine (RPV), known as RPV LA for safety, pharmacokinetics and acceptability.

METHODS

HPTN 076 (NTC 02165202) was a phase 2, double-blind, 2:1 randomized trial comparing the safety of 1200mg RPV LA (LA) to placebo (P). The study included a 28-day oral run-in phase of daily, self- administered oral RPV (25 mg), with directly observed oral dosing about six times. Of 136 enrolled sexually active, HIV-uninfected, low HIV-risk African (100) and US (36) adult women, injectable product was administered in two gluteal, intramuscular (IM) injections once every eight weeks to 122 participants following the oral run-in phase. A maximum of six injection time points occurred over a 48-week period. Acceptability, safety, tolerability and pharmacokinetic (PK) data were collected throughout the study. This paper includes primary endpoint data collected up to the week 52 post enrollment.

FINDINGS

The median age of the enrolled population was 31 years (IQR: 25,38), median weight 75 kg (IQR: 64, 89), median body mass index (BMI) 30 (IQR: 27, 35), 46% married, 94% Black and 60% unemployed. A total of 122 (80 LA, 42 P) women received at least one injection and 98 (64 LA, 34 P) received all six injections. During the injection phase, three women withdrew from the study (2 LA, 1 P) and 16 women discontinued study product (10 LA, 6 P). Fourteen women (11 LA and 3 P) discontinued oral study product and did not enter the injection phase. Study product discontinuations were not significantly different between the two arms throughout. Of the product discontinuations in the injection phase, 8% in LA and 5% in P arm were due to adverse events (AEs), including one randomized to the P arm with prolonged QTc interval on EKG. The proportion of women who experienced Grade 2 or higher AEs during the injection phase as the primary outcome was not significantly different between the two arms [73.8%, 95% CI: (63.2%, 82.1%) for LA and 73.8%, 95% CI: (58.9%, 84.7%), p>0.99]. Transient Grade ≥2 liver abnormalities occurred in 14% of women in the LA arm compared with 12% in P arm. Three LA women (4%) developed Grade 3 injection site reactions compared with none in P arm. In participants who received at least 1 injection, the geometric mean of overall RPV trough concentrations (Ctrough) was 62.2 ng/mL. In participants who received all six injections, the geometric mean of CTrough through the injection phase and after the last injection were 72.8 ng/mL and 100.9 ng/mL, respectively. At week 52 (eight weeks after last injection), the geometric mean of RPV Ctrough was 75.0 ng/mL. At the last injection visit (Week 44), 80 % of women who answered acceptability questions strongly agreed that they would think about using- and 68% that they would definitely use a PrEP injectable in the future.

INTERPRETATION

RPV LA IM injections every eight weeks in African and US women were safe and acceptable. Overall, despite more injection site reactions and pain in the participants receiving RPV LA the injections were well tolerated. Data from this study support the further development of injectable PrEP agents.

Impact of Spin-Orbit Torque on Spin-Transfer Torque Switching in Magnetic Tunnel Junctions

The paper presents our simulated results showing the substantial improvement of both switching speed and energy consumption in a perpendicular magnetic tunnel junction (p-MTJ), a core unit of Spin-Transfer-Torque Magnetic Random Access Memory (STT-MRAM), by the help of additional Spin-Orbit-Torque (SOT) write pulse current (WPSOT). An STT-SOT hybrid torque module for OOMMF simulation is implemented to investigate the switching behavior of a 20 nm cell in the p-MTJ. We found that the assistance of WPSOT to STT write pulse current (WPSTT) have a huge influence on the switching behavior of the free layer in the p-MTJ. For example, we could dramatically reduce the switching time (tSW) by 80% and thereby reduce the write energy over 70% as compared to those in the absence of the WPSOT. Even a very tiny amplitude of WPSOT (JSOT of the order of 102 A/m2) substantially assists to reduce the critical current density for switching of the free layer and thereby decreases the energy consumption as well. It is worth to be pointed out that the energy can be saved further by tuning the WPSOT parameters, i.e., amplitude and duration along at the threshold WPSTT. Our findings show that the proposed STT-SOT hybrid switching scheme has a great impact on the MRAM technology seeking the high speed and low energy consumption.

P6371Network characteristics of a hypertension referral system in western kenya

Introduction

The Strengthening Referral Networks for Management of Hypertension Across the Health System (STRENGTHS) trial is creating and testing interventions to improve the effectiveness of referral networks for patients with hypertension in Western Kenya.

Purpose

Network analysis of facility-based healthcare providers was used to understand the existing network of referrals. The ultimate goal was to identify both structural gaps and opportunities for implementation of the planned intervention.

Methods

A network survey was administered to providers who deliver care to patients with hypertension asking individuals to nominate a) individuals to whom, and b) facilities to which they refer patients, both up and down the health system. We analyzed survey data using centrality measures of in-degree and out-degree (number of links each provider received and sent, respectively), as well as fitting a core-periphery (CP) model. A higher CP indicates a strong referral network, while a lower CP indicates a relatively weaker network.

Results

Data were collected from 130 providers across 39 sites within 7 geographically separate network clusters. Each cluster consists of a mix of primary, secondary, and/or tertiary facilities. Compared to a perfect CP referral network model (Correlation Score [CP] = 1.00) and a random referral network model (CP = 0.200), the provider referral networks within each cluster showed a weak tendency for CP structure. There was a large range in CP from 0.334 to 0.639. In contrast, cluster-level facility networks showed a strong tendency for CP structure, with a CP range of 0.857 to 0.949.

Core Periphery Correlation Scores [CP] Network Cluster 1 Cluster 2 Cluster 3 Cluster 4 Cluster 5 Cluster 6 Cluster 7 Provider Referrals 0.433 0.424 0.334 0.639 0.535 0.448 0.407 Facility Referrals 0.949 0.894 0.871 0.949 0.949 0.904 0.857 Each cluster represents a geographically separate referral network. A random referral network would reveal a CP score of 0.200; while a perfect referral network would give a CP of 1.00.

Referral Network Models

Conclusions

The current health system across Western Kenya does not demonstrate a strong network of referrals between providers for patients with hypertension. While facility-to-facility referrals are more in-line with a perfect referral model, there are gaps in communication between the specific providers. These results highlight the need for STRENGTHS to design and test interventions that strengthen provider referral patterns in order to improve blood pressure control and reduce cardiovascular risk.

Acknowledgement/Funding

National Institutes of Health: National Heart Lung and Blood Institute, Doris Duke Charitable Foundation:International Clinical Research Fellowship

The role of intraoperative cholangiography in patients undergoing laparoscopic cholecystectomy for acute gallstone pancreatitis: is magnetic resonance cholangiopancreatography needed?

INTRODUCTION

Intraoperative cholangiography is sporadically used in patients undergoing laparoscopic cholecystectomy to delineate common bile duct anatomy and exclude retained stones. In patients with acute gallstone pancreatitis, intraoperative cholangiography may reduce the need for preoperative magnetic resonance cholangiopancreatography.

MATERIALS AND METHODS

A retrospective review of a prospectively collected patient database was undertaken over a 15-year period. The primary objective was to evaluate intraoperative assessment of the common bile duct with intraoperative cholangiography in patients with acute gallstone pancreatitis.

RESULTS

A total of 2215 patients underwent laparoscopic cholecystectomy between October 1998 and December 2013; 113 patients (of whom 77 were women) with a mean age of 54 years (range 16-88 years) were diagnosed with acute gallstone pancreatitis. Of these, 102 patients (90%) underwent laparoscopic cholecystectomy with intraoperative cholangiography, which was normal in 89 cases. Thirteen patients had choledocholithiasis on intraoperative cholangiography, 11 of whom were managed with concomitant trans-cystic duct exploration and clearance. Two patients required postoperative endoscopic retrograde cholangiopancreatography.

CONCLUSIONS

In patients diagnosed with acute gallstone pancreatitis, it is reasonable to proceed directly to surgery using intraoperative cholangiography on the same admission as the definitive assessment of the common bile duct. This negates the need for magnetic resonance cholangiopancreatography and can translate into cost savings and reduced length of stay.

Meta-analysis of the use of sterilized mosquito net mesh for inguinal hernia repair in less economically developed countries

Background

Inguinal hernias are common in less economically developed countries (LEDCs), and associated with significant morbidity and mortality. Tension-free mesh repair is the standard treatment worldwide. Lack of resources combined with the high cost of commercial synthetic mesh (CSM) have limited its use in LEDCs. Sterilized mosquito net mesh (MNM) has emerged as a low-cost, readily available alternative to CSM. The aim of this systematic review and meta-analysis was to evaluate the safety and efficacy of MNM for the use in hernia repair in LEDCs.

Methods

A systematic review and data meta-analysis of all published articles from inception to August 2018 was performed. Cochrane Central Register of Controlled Trials, MEDLINE and Embase databases were searched. The primary outcome measure was the overall postoperative complication rate of hernia repair when using MNM. Secondary outcome measures were comparisons between MNM and CSM with regard to overall complication rate, wound infection, chronic pain and haematoma formation.

Results

A total of nine studies were considered relevant (3 RCTs, 1 non-randomized trial and 5 prospective studies), providing a total cohort of 1085 patients using MNM. The overall complication rate for hernia repair using MNM was 9·3 per cent. There was no significant difference between MNM and CSM regarding the overall postoperative complication rate (odds ratio 0·99, 95 per cent c.i. 0·65 to 1·53; P = 0·98), severe or chronic pain (OR 2·52, 0·36 to 17·42; P = 0·35), infection (OR 0·56, 0·19 to 1·61; P = 0·28) or haematoma (OR 1·05, 0·62 to 1·78; P = 0·86).

Conclusion

MNM has a low overall postoperative complication rate and is unlikely to be inferior to CSM in terms of safety and efficacy. MNM is a suitable low-cost alternative to CSM in the presence of financial constraint.

Meta-analysis of the influence of lifestyle changes for preoperative weight loss on surgical outcomes

Background

The aim was to investigate whether preoperative weight loss results in improved clinical outcomes in surgical patients with clinically significant obesity.

Methods

This was a systematic review and aggregate data meta-analysis of RCTs and cohort studies. PubMed, MEDLINE, Embase and CINAHL Plus databases were searched from inception to February 2018. Eligibility criteria were: studies assessing the effect of weight loss interventions (low-energy diets with or without an exercise component) on clinical outcomes in patients undergoing any surgical procedure. Data on 30-day or all-cause in-hospital mortality were extracted and synthesized in meta-analyses. Postoperative thromboembolic complications, duration of surgery, infection and duration of hospital stay were also assessed.

Results

A total of 6060 patients in four RCTs and 12 cohort studies, all from European and North American centres, were identified. Most were in the field of bariatric surgery and all had some methodological limitations. The pooled effect estimate suggested that preoperative weight loss programmes were effective, leading to significant weight reduction compared with controls: mean difference –7·42 (95 per cent c.i. –10·09 to –4·74) kg (P &lt; 0·001). Preoperative weight loss interventions were not associated with a reduction in perioperative mortality (odds ratio 1·41, 95 per cent c.i. 0·24 to 8·40; I2 = 0 per cent, P = 0·66) but the event rate was low. The weight loss groups had shorter hospital stay (by 27 per cent). No differences were found for morbidity.

Conclusion

This limited preoperative weight loss has advantages but may not alter the postoperative morbidity or mortality risk.

Systematic review and meta-analysis of the role of metronidazole in post-haemorrhoidectomy pain relief

AIM

Conventional haemorrhoidectomy is still considered the reference standard for the management of severe or recurrent haemorrhoids. Pain is reported by patients to be the most common postoperative complication. Although the literature lacks a consensus on its effectiveness, metronidazole is often used to reduce postoperative pain. We have performed a meta-analysis of all randomized controlled trials (RCTs) that investigated the use of metronidazole for pain relief after haemorrhoidectomy.

METHOD

A systematic review was undertaken in accordance with the PRISMA protocol using the MESH headings 'haemorrhoidectomy', 'hemorhoidectomy', 'hemorrhoidectomy', 'haemorrhoid', 'metronidazole', 'Flagyl^® ' 'antibiotic' and 'pain'. The search returned 421 articles of which eight were RCTs suitable for inclusion in the review with a total population of 437 patients. The outcomes of interest were postoperative pain intensity on days 1, 2 and 7 and on first defaecation as measured using a visual analogue scale.

RESULTS

The meta-analysis demonstrated a significant reduction in postoperative pain for patients treated with metronidazole with a reduced mean difference for the metronidazole group on day 1 of -1.42 (95% CI: -2.14 to -0.69, P = 0.0001), on day 2 of -1.43 (95% CI: -2.45 to -0.40, P = 0.006) and on day 7 of -2.40 (95% CI: -3.10 to -1.71, P < 0.00001). Pain on first defaecation was likewise reduced with a mean difference of -1.38 (95% CI: -2.15 to -0.60, P = 0.0005). Limitations of this study include variation in the grade of haemorrhoids treated and variability in the quality of included studies.

CONCLUSION

Metronidazole is a cheap, safe and effective intervention for reducing postoperative pain following conventional haemorrhoidectomy.

Disabled women's attendance at community women's groups in rural Nepal

There is strong evidence that participatory approaches to health and participatory women's groups hold great potential to improve the health of women and children in resource poor settings. It is important to consider if interventions are reaching the most marginalized, and therefore we examined disabled women's participation in women's groups and other community groups in rural Nepal. People with disabilities constitute 15% of the world's population and face high levels of poverty, stigma, social marginalization and unequal access to health resources, and therefore their access to women's groups is particularly important. We used a mixed methods approach to describe attendance in groups among disabled and non-disabled women, considering different types and severities of disability. We found no significant differences in the percentage of women that had ever attended at least one of our women's groups, between non-disabled and disabled women. This was true for women with all severities and types of disability, except physically disabled women who were slightly less likely to have attended. Barriers such as poverty, lack of family support, lack of self-confidence and attendance in many groups prevented women from attending groups. Our findings are particularly significant because disabled people's participation in broader community groups, not focused on disability, has been little studied. We conclude that women's groups are an important way to reach disabled women in resource poor communities. We recommend that disabled persons organizations help to increase awareness of disability issues among organizations running community groups to further increase their effectiveness in reaching disabled women.

Heterodyne frequency-domain multispectral diffuse optical tomography of breast cancer in the parallel-plane transmission geometry

PURPOSE

The authors introduce a state-of-the-art all-optical clinical diffuse optical tomography (DOT) imaging instrument which collects spatially dense, multispectral, frequency-domain breast data in the parallel-plate geometry.

METHODS

The instrument utilizes a CCD-based heterodyne detection scheme that permits massively parallel detection of diffuse photon density wave amplitude and phase for a large number of source-detector pairs (10(6)). The stand-alone clinical DOT instrument thus offers high spatial resolution with reduced crosstalk between absorption and scattering. Other novel features include a fringe profilometry system for breast boundary segmentation, real-time data normalization, and a patient bed design which permits both axial and sagittal breast measurements.

RESULTS

The authors validated the instrument using tissue simulating phantoms with two different chromophore-containing targets and one scattering target. The authors also demonstrated the instrument in a case study breast cancer patient; the reconstructed 3D image of endogenous chromophores and scattering gave tumor localization in agreement with MRI.

CONCLUSIONS

Imaging with a novel parallel-plate DOT breast imager that employs highly parallel, high-resolution CCD detection in the frequency-domain was demonstrated.

Prophylactic mesh use during primary stoma formation to prevent parastomal hernia

Introduction Parastomal hernia (PSH) is a common problem following stoma formation. The optimal technique for stoma formation is unknown although recent studies have focused on whether placement of prophylactic mesh at stoma formation can reduce PSH rates. The aim of this study was to systematically review use of prophylactic mesh versus no mesh with regard to occurrence of PSH and peristomal complications. Methods A systematic search was performed using PubMed, Embase™ and the Cochrane Library to identify randomised controlled trials that analysed placement of prophylactic mesh versus no mesh at time of initial surgery. Meta-analysis was performed using random effects methods. Results A total of 506 studies were identified by our search strategy. Of these, 8 studies were included, involving 430 patients (217 mesh vs 213 no mesh). Prophylactic mesh placement resulted in a significantly lower rate of PSH formation (42/217 [19.4%] vs 92/213 [43.2%]) with a combined risk ratio of 0.40 (95% confidence interval [CI]: 0.21-0.75, p=0.004). Placement of prophylactic mesh did not result in increased peristomal complications (15/218 [6.9%] vs 16/227 [7.0%]) with a combined risk ratio of 1.0 (95% CI: 0.49-2.01, p=0.990). Conclusions Prophylactic placement of mesh at primary stoma formation may reduce the incidence of PSH, without an increase in peristomal complications. However, the overall quality of the randomised controlled trials included in the meta-analysis was poor, and should prompt caution regarding the applicability of the findings of the individual studies and the meta-analysis to everyday practice.

Current trends in etiology, prognosis and therapeutic aspects of Parkinson's disease: a review

Parkinson's disease (PD) is a movement disorder, mainly affecting population consisting of the aged. PD occurs chiefly due to progressive loss of dopaminergic neurons in nigrostriatal pathway. Largely, PD patients suffer from non-motor symptoms, such as depression, anxiety, fatigue, and sleep disorders, that needs further investigation and addressing during PD research. Depression in PD is a predominant and complex symptom, and its pathology exists extrinsic to the nigrostriatal system. This disease can  ultimately be managed by a combination of regular physiotherapy and proper medication. Taking together the present scenario of PD, including the nature of disease, characteristics, treatment, diagnosis of the patients with PD, these outcomes were reviewed to be explored along with many speech-based solutions to PD in this study. This neurodegenerative disorder needs advancement in  research and development which  can help patients with PD to lead a normal life.

Linking genomic reorganization to tumor initiation via the giant cell cycle

To investigate the mechanisms underlying our recent paradoxical finding that mitotically incapacitated and genomically unstable polyploid giant cancer cells (PGCCs) are capable of tumor initiation, we labeled ovarian cancer cells with α-tubulin fused to green fluorescent protein, histone-2B fused to red fluorescent protein and FUCCI (fluorescent ubiquitination cell cycle indicator), and tracked the spatial and time-dependent change in spindle and chromosomal dynamics of PGCCs using live-cell fluorescence time-lapse recording. We found that single-dose (500 nm) treatment with paclitaxel paradoxically initiated endoreplication to form PGCCs after massive cell death. The resulting PGCCs continued self-renewal via endoreplication and further divided by nuclear budding or fragmentation; the small daughter nuclei then acquired cytoplasm, split off from the giant mother cells and acquired competency in mitosis. FUCCI showed that PGCCs divided via truncated endoreplication cell cycle (endocycle or endomitosis). Confocal microscopy showed that PGCCs had pronounced nuclear fragmentation and lacked expression of key mitotic proteins. PGCC-derived daughter cells were capable of long-term proliferation and acquired numerous new genome/chromosome alterations demonstrated by spectral karyotyping. These data prompt us to conceptualize a giant cell cycle composed of four distinct but overlapping phases, initiation, self-renewal, termination and stability. The giant cell cycle may represent a fundamental cellular mechanism to initiate genomic reorganization to generate new tumor-initiating cells in response to chemotherapy-induced stress and contributes to disease relapse.

Parietex™ Composite mesh versus DynaMesh®-IPOM for laparoscopic incisional and ventral hernia repair: a retrospective cohort study

INTRODUCTION Laparoscopic incisional and ventral hernia repair (LIVHR) is widely accepted and safe but the type of mesh used is still debated. We retrospectively compared postoperative outcomes with two different meshes commonly used in LIVHR. METHODS This is a retrospective study of patients who underwent incisional hernia repair between January 2008 and December 2010. Two meshes were used: Parietex™ Composite (Covidien, New Haven, CT, USA) and the DynaMesh^®-IPOM (FEG Textiltechnik mbH, Aachen, Germany). The two groups were compared with respect to recurrence rates, incidence of seroma and intestinal obstruction. RESULTS Among the 88 patients who underwent LIVHR, 75 patients (85.2%) presented with primary incisional hernia, 10 (11.4%) presented with a first recurrence and 3 (3.4%) presented with a second recurrence. Median follow-up was 53.6 months (range 40-61 months). 12.9% of patients had recurrence in the Parietex™ Composite mesh group (n=62) in comparison to 3.8% in the DynaMesh^®-IPOM mesh group (n=26; P=0.20). DynaMesh^®-IPOM was associated with a significantly higher incidence of intestinal obstruction secondary to adhesions (11.5% vs. 0%, P=0.006) and lower incidence of seroma and haematoma formation compared to Parietex™ composite mesh group (0% vs. 6.4% of patients; P=0.185). CONCLUSIONS LIVHR is a safe and feasible technique. Dynamesh^®-IPOM is associated with a significantly higher incidence of adhesion related bowel obstruction, albeit with a lower incidence of recurrence, seroma and haematoma formation compared with Parietex™ Composite mesh. However, there is a need for further well-designed, multicentre randomised controlled studies to investigate the use of these meshes.

Meta-analysis of closure of the fascial defect during laparoscopic incisional and ventral hernia repair

Background

Laparoscopic incisional and ventral hernia repair (LIVHR) is being used increasingly, with reported outcomes equivalent to those of open hernia repair. Closure of the fascial defect (CFD) is a technique that may reduce seroma formation and bulging after LIVHR. Non-closure of the fascial defect makes the repair of larger defects easier and reduces postoperative pain. The aim of this systematic review was to determine whether CFD affects the rate of adverse outcomes, such as recurrence, pseudo-recurrence, mesh eventration or bulging, and the rate of seroma formation.

Methods

A systematic search was performed of PubMed, Ovid, the Cochrane Library, Google Scholar and Scopus to identify RCTs that analysed CFD with regard to rates of adverse outcomes. A meta-analysis was done using fixed-effect methods. The primary outcome of interest was adverse events. Secondary outcomes were seroma, postoperative pain, mean hospital stay, mean duration of operation and surgical techniques employed.

Results

A total of 16 studies were identified involving 3638 patients, 2963 in the CFD group and 675 in the non-closure of facial defect group. Significantly fewer adverse events were noted following CFD than non-closure (4·9 per cent (79 of 1613) versus 22·3 per cent (114 of 511)), with a combined risk ratio (RR) of 0·25 (95 per cent c.i. 0·18 to 0·33; P &lt; 0·001). CFD resulted in a significantly lower rate of seroma (2·5 per cent (39 of 1546) versus 12·2 per cent (47 of 385)), with a combined RR of 0·37 (0·23 to 0·57; P &lt; 0·001), and shorter duration of hospital stay. No significant difference was noted in postoperative pain.

Conclusion

CFD during LIVHR reduces the rate of seroma formation and adverse hernia-site events.

The impact of cardiopulmonary exercise testing on patients over the age of 80 undergoing elective colorectal cancer surgery

AIM

Advanced age and occult cardiorespiratory disease are associated with increased morbidity and mortality following surgery. Cardiopulmonary exercise testing (CPET) may allow the identification of high-risk patients and facilitate planned postoperative critical care support. The aim of this study was to determine whether preoperative CPET in patients aged over 80 undergoing elective colorectal cancer resection was associated with improved outcome.

METHOD

All patients aged 80 years and above undergoing elective colorectal cancer resection between 1 March 2011 and 1 September 2013 were retrospectively analysed. Referral for CPET testing was at the discretion of the operating surgeon. Postoperative critical care unit (CCU) admission was based upon the CPET results.

RESULTS

Ninety-four patients were identified, of whom 48 underwent CPET testing. The CPET group were significantly older than the non-CPET group (85 vs 83 years, P = 0.04) and were more likely to have a planned admission to CCU postoperatively (P < 0.0001). Despite the increased use of CCU resources, the overall CCU length of stay (LOS) in the CPET group did not differ from the non-CPET group, but the non-CPET group had a higher proportion of Level-3 care. There were no differences in the incidence of unplanned CCU admission between the CPET and the non-CPET group (P = 0.23). There were no differences in overall LOS between the two groups (P = 0.42). There was no difference in mortality (P = 0.11), overall complications (P = 0.53) or severe complications (P = 0.3).

CONCLUSION

Preoperative CPET testing in patients aged over 80 undergoing elective colorectal cancer resection allows identification of higher-risk patients and mitigation of risk by preemptive admission to a CCU. This stratification allows equivalent results to be achieved in high- and low-risk elderly patients undergoing colorectal surgery.

Optically trapping tumor cells to assess differentiation and prognosis of cancers

We report an optical trapping method that may enable assessment of the differentiation status of cancerous cells by determining the minimum time required for cell-cell adhesion to occur. A single, live cell is trapped and brought into close proximity of another; the minimum contact time required for cell-cell adhesion to occur is measured using transformed cells from neural tumor cell lines: the human neuroblastoma SK-N-SH and rat C6 glioma cells. Earlier work on live adult rat hippocampal neural progenitors/stem cells had shown that a contact minimum of ~5 s was required for cells to adhere to each other. We now find the average minimum time for adhesion of cells from both tumor cell lines to substantially increase to ~20-25 s, in some cases up to 45 s. Upon in vitro differentiation of these cells with all-trans retinoic acid the average minimum time reverts to ~5-7 s. This proof-of-concept study indicates that optical trapping may be a quick, sensitive, and specific method for determining differentiation status and, thereby, the prognosis of cancer cells.

Lethal and nonlethal murine malarial infections differentially affect apoptosis, proliferation, and CD8 expression on thymic T cells

Although thymic atrophy and apoptosis of the double-positive (DP) T cells have been reported in murine malaria, comparative studies investigating the effect of lethal and nonlethal Plasmodium infections on the thymus are lacking. We assessed the effects of P. yoelii lethal (17XL) and nonlethal (17XNL) infections on thymic T cells. Both strains affected the thymus. 17XL infection induced DP T-cell apoptosis and a selective decrease in surface CD8 expression on developing thymocytes. By contrast, more severe but reversible effects were observed during 17XNL infection. DP T cells underwent apoptosis, and proliferation of both DN and DP cells was affected around peak parasitemia. A transient increase in surface CD8 expression on thymic T cells was also observed. Adult thymic organ culture revealed that soluble serum factors, but not IFN-γ or TNF-α, contributed to the observed effects. Thus, lethal and nonlethal malarial infections led to multiple disparate effects on thymus. These parasite-induced thymic changes are expected to impact the naïve T-cell repertoire and the subsequent control of the immune response against the parasite. Further investigations are required to elucidate the mechanism responsible for these disparate effects, especially the reversible involution of the thymus in case of nonlethal infection.

Estimating inter-annual diversity of seasonal agricultural area using multi-temporal resourcesat data

The present study aims at analysis of spatial and temporal variability in agricultural land cover during 2005-6 and 2011-12 from an ongoing program of annual land use mapping using multidate Advanced Wide Field Sensor (AWiFS) data aboard Resourcesat-1 and 2. About 640-690 multi-temporal AWiFS quadrant data products per year (depending on cloud cover) were co-registered and radiometrically normalized to prepare state (administrative unit) mosaics. An 18-fold classification was adopted in this project. Rule-based techniques along with maximum-likelihood algorithm were employed to deriving land cover information as well as changes within agricultural land cover classes. The agricultural land cover classes include - kharif (June-October), rabi (November-April), zaid (April-June), area sown more than once, fallow lands and plantation crops. Mean kappa accuracy of these estimates varied from 0.87 to 0.96 for various classes. Standard error of estimate has been computed for each class annually and the area estimates were corrected using standard error of estimate. The corrected estimates range between 99 and 116 Mha for kharif and 77-91 Mha for rabi. The kharif, rabi and net sown area were aggregated at 10 km × 10 km grid on annual basis for entire India and CV was computed at each grid cell using temporal spatially-aggregated area as input. This spatial variability of agricultural land cover classes was analyzed across meteorological zones, irrigated command areas and administrative boundaries. The results indicate that out of various states/meteorological zones, Punjab was consistently cropped during kharif as well as rabi seasons. Out of all irrigated commands, Tawa irrigated command was consistently cropped during rabi season.

Influence of Intensity and Duration of Yoga on Anxiety and Depression Scores Associated with Chronic Illness

Background:

Chronic illness is commonly associated with anxiety and depression. Both anxiety and depression respond to yoga. However, there is no report on the association between the intensity and duration of yoga practice with the benefits seen.

Aim:

The present study was intended to determine whether the daily duration of yoga practice and the duration of experience in months would predict anxiety and depression, associated with chronic illness.

Subjects and Methods:

Seven hundred and sixty-three volunteers with ages between 14 and 86 years (group mean age standard deviation, 50.2 [14.2]) who attended a 7 day residential yoga camp in the north of India were included in this cross-sectional study. All participants had chronic illnesses, which were under control with treatment, and which were categorized and are detailed. Participants were assessed for state anxiety scores using State-Trait Anxiety Inventory and for anxiety with hospital anxiety and depression scale (HADS-A), and depression was assessed using HADS-D scores of the HADS. Linear multiple regression analyses were performed using PASW SPSS version 18.0 (Armonk, New York, U.S.) to determine how the daily and monthly duration of yoga practice could influence state anxiety, hospital anxiety and depression of the participants.

Results:

Yoga practice in months and the time spent practicing yoga each day significantly predict the level of state anxiety (P < 0.001, P = 0.03) and HAD-A (P < 0.01, P < 0.01). The duration of yoga practice in months alone was a significant predictor of the HAD-D (P < 0.01).

Conclusions:

The results suggest that the duration of yoga practice in months and daily practice in minutes predict anxiety associated with chronic illness. In contrast the duration of yoga practice in months alone, predicted depression scores.

Perforation of gastrointestinal tract by poorly conspicuous ingested foreign bodies: radiological diagnosis

Perforation of gastrointestinal (GI) tract by ingested bone fragments, toothpicks and dentures is rare but remains an important life-threatening condition, and the outcomes are poorer when the diagnosis is delayed. Invariably, clinical and radiographic diagnosis is difficult as most patients will have no recollection of ingesting a foreign body, whereas these subtle objects are often not visible on radiographs. In search for the diagnosis, CT is the modality of choice, but ultrasound imaging may be first requested in patients presenting with symptoms of acute appendicitis, cholecystitis, pyelonephritis or pelvic inflammatory disease when an ingested foreign body is not considered. Although ultrasound has limited value in depicting a foreign body, it can frequently uncover secondary signs of perforation. However, the rarity of this condition combined with non-specific clinical presentation and the propensity of these small perforating objects to be subtle makes establishing the correct diagnosis by the radiologist challenging. Therefore, understanding of the appearances of GI perforation seen on CT images or general abdominal ultrasound will aid the radiologist in the diagnosis of this important yet often unsuspected condition. This will lead to earlier diagnosis and surgical management. In this article, we illustrate the spectrum of CT, radiographic and ultrasound imaging features seen in GI perforation caused by swallowed bone fragments, toothpicks, cocktail sticks and dentures.

Management of gallbladder dyskinesia: patient outcomes following positive ⁹⁹mtechnetium (Tc)-labelled hepatic iminodiacetic acid (HIDA) scintigraphy with cholecystokinin (CCK) provocation and laparoscopic cholecystectomy

AIMS

To evaluate clinical outcomes in patients with typical biliary pain, normal ultrasonic findings, and a positive (99m)technetium (Tc)-labelled hepatic iminodiacetic acid analogue (HIDA) scintigraphy with cholecystokinin (CCK) provocation indicating gallbladder dyskinesia, as per Rome III criteria, undergoing laparoscopic cholecystectomy (LC).

METHODS AND MATERIALS

Consecutive patients undergoing LC for gallbladder dyskinesia were identified retrospectively. They were followed up by telephone interview and review of the electronic case records to assess symptom resolution.

RESULTS

One hundred consecutive patients (median age 44; 80% female) with abnormal gallbladder ejection fraction (GB-EF <35%) were followed up for a median of 12 months (range 2-80 months). Following LC, 84% reported symptomatic improvement and 52% had no residual pain. Twelve percent had persisting preoperative-type pain of either unchanged or worsening severity. Neither pathological features of chronic cholecystitis (87% of 92 incidences when histology available) nor reproduction of pain on CCK injection were significantly predictive of symptom outcome or pain relief post-LC.

CONCLUSION

In one of the largest outcome series of gallbladder dyskinesia patients in the UK with a positive provocation HIDA scintigraphy examination and LC, the present study shows that the test is a useful functional diagnostic tool in the management of patients with typical biliary pain and normal ultrasound, with favourable outcomes following surgery.

New enterant in the class of uropathogens-Shewanella algae

A 70 year old diabetic male presented with fever, urgency of micturition, oliguria, swelling over both legs. His midstream urine sample was sent for microbiological examination and it revealed Shewanella algae. Patient was treated with antibiotics and he recovered completely after treatment.DOI: http://dx.doi.org/10.3126/ajms.v6i4.11503 Asian Journal of Medical Sciences Vol.6(4) 2015 92-95

Outcome after liver resection in patients presenting with simultaneous hepatopulmonary colorectal metastases

BACKGROUND

The most common sites of metastasis from colorectal cancer (CRC) are hepatic and pulmonary; they can present simultaneously (hepatic and pulmonary metastases) or sequentially (hepatic then pulmonary metastases, or vice versa). Simultaneous disease may be aggressive, and thus may be approached with caution by the clinician. The aim of this study was to determine the outcomes following hepatic and pulmonary resection for simultaneously presenting metastatic CRC.

METHODS

A retrospective review was undertaken of a prospectively maintained database to identify patients presenting with simultaneous hepatopulmonary disease who underwent hepatic resection. Patients' electronic records were used to identify clinicopathological variables. The log rank test was used to determine survival, and χ(2) analysis to determine predictors of failure of intended treatment.

RESULTS

Fifty-nine patients were identified and underwent hepatic resection; median survival was 45·4 months and the 5-year survival rate 38 per cent. Twenty-two patients (37 per cent) did not have the intended pulmonary intervention owing to progression or recurrence of disease. Thirty-seven patients who progressed to hepatopulmonary resection had a median survival of 54·2 months (5-year survival rate 43 per cent). Those who had hepatic resection alone had a median survival of 24·0 months (5-year survival rate 30 per cent). Failure to progress to pulmonary resection was predicted by heavy nodal burden of primary colorectal disease and bilobar hepatic metastases. Redo pulmonary surgery following pulmonary recurrence did not confer a survival benefit.

CONCLUSION

Selected patients with simultaneous hepatopulmonary CRC metastases should be considered for attempted curative resection, but some patients may not receive the intended treatment owing to progression of pulmonary disease after hepatic resection.

Silicon-on-insulator shortwave infrared wavelength meter with integrated photodiodes for on-chip laser monitoring

This paper demonstrates a very compact wavelength meter for on-chip laser monitoring in the shortwave infrared wavelength range based on an optimized arrayed waveguide grating (AWG) filter with an integrated photodiode array. The AWG response is designed to obtain large nearest neighbor crosstalk (i.e. large overlap) between output channels, which allows accurately measuring the wavelength of a laser under test using the centroid detection technique. The passive AWG is fabricated on a 220 nm silicon-on-insulator (SOI) platform and is combined with GaInAsSb-based photodiodes. The photodiodes are heterogeneously integrated on the output grating couplers of the AWG using DVS-BCB adhesive bonding. The complete device with AWG and detectors has a footprint of only 2 mm(2) while the measured accuracy and resolution of the detected wavelength is better than 20pm.