Role of percutaneous cholecystostomy tube placement in the management of acute calculus cholecystitis in high risk patients

Objective: To evaluate the utility of percutaneous cholecystostomy tube in patients with acute calculus cholecystitis, who are considered unfit for immediate surgery. Study Design: Observational study. Place and Duration of Study: The Aga Khan University Hospital, Karachi, Pakistan, from January 2010 to December 2014. Methodology: All adult patients who underwent percutaneous cholecystostomy tube placement for acute calculous cholecystitis were included. These patients were divided into two groups for further analysis. Group-I consisted those who had interval cholecystectomy after tube placement and Group-II were those who had no further treatment. Recurrence of symptoms, infections and operation related complications were noted. Results: Sixty-five patients met the inclusion criteria. Mean age was 58.5 years. Forty-four patients (67.7%) were males. Forty-three patients underwent interval cholecystectomy (Group-I) and 22 did not (Group-II). Mean operative time was 134.9 +57.8 minutes. Five (11.6%) patients were converted to open cholecystectomy, two (4.6%) developed CBD injury, and seven (16.2%) developed surgical site infection. In Group-II, three patients (13.6%) developed recurrence of symptoms and 19 (86.4%) remained symptom-free. Catheter related problems occurred in four (18%) patients. Mean follow-up was 19 +8 months. Conclusion: Percutaneous cholecystostomy is a good alternative for patients unfit to undergo immediate surgery. Recurrence of symptoms after tube removal are in a low range; therefore, it can be considered a definitive management for high risk patients. Laparoscopic cholecystectomy after tube placement becomes technically challenging

Over a decade of changing trends in surgical mortality; audit from a tertiary care hospital

Objective: A retrospective audit of the trend of mortality in the general surgery service at our hospital over the last decade was conducted to reflect the complexity of cases being seen. Methods: Mortalities of 8 separate years, a decade apart, namely 1997, 1998, 1999, and 2000 as initial years (GroupI) and 2011, 2012, 2013 and 2014 as recent years (Group-II) were reviewed. Results: Total number of admissions in the service and surgeries performed during these two periods experienced an increase of 50.7% & 64.2 % respectively. The total mortalities showed an increase with 139 (mortality rate 0.96%)seen in Group I to 285 (mortality rate 1.31%) seen in Group II a percentage increase of 105%. Comparing the operative mortality, separately, mortality rate dropped from 1.21% to 1.16% of all surgeries. Analyzing nonoperative mortality showed a significant increase from six deaths in Group-I comprising 4.3% to 76 non-operative deaths in Group-II corresponding to 26.7% (p=0.000). Deaths due to Trauma increased from 12.9% to 25.3%, p=0.04, a reversed trend was seen in deaths due to GI Bleeding 11.5% to 3.2%, p=0.001. Significantly more patients in Group-II had higher ASA levels as compared to Group-I (62% vs. 46%, p\u3c0.005). Conclusion: This study shows an increase in total mortality rate over the years, change was mainly due to an increase in non-operative mortality. Trauma became the predominant cause of deat

Pancreaticoduodenectomy: A developing country perspective

Objective: To review retrospectively, the resultsof Whipple\u27s procedure from 1986 to December 2009 at the Aga Khan University Hospital. Methods: Patient\u27s case notes were reviewed to extract information related to demographics, clinical and laboratory data, operative procedure and post operative period. Surgical mortality was defined as death within 30 days of procedure. Results: Hundred and twenty one patients underwent a successful pancreaticoduodenectomy during this period. There were 78 males and 43 females. Most presented with clinical features of obstructive jaundice. Perioperative evaluation in the majority included an abdominal ultrasound and contrast enhanced CT scan. A preoperative ERCP was performed in 64 (53%) patients and a stent was placed in 32 (26%). Stent related sepsis was noted in 8 patients (25%). Eighty four (69%) patients underwent a standard resection, 31% had a pylorus preserving procedure. The commonest pathology was adeno-carcinoma located in the pancreatic head or periampullary area. Post operative morbidity was noted in 54% of patients, the commonest being chest infection (20%) followed by delayed gastric emptying and pancreatic anastomotic leak. There were 12 perioperative deaths giving a surgical mortality of 10%. Conclusion: To our understanding this is the largest series of consecutive pancreaticoduodenectomies reported in Pakistan. Our morbidity and mortality rates compare favourably with international centers of similar yearly case volume. There is a need to establish regional centers to effectively manage complex disease conditions and improve the standard of care offered to our patients

Simulation and Complexity Analysis of Iterative Interference Cancellation Receivers for LTE/LTE-Advanced

The paper details the simulation of a single user MIMO receiver operating according to the 3GPP/LTE standard applying a Parallel or Successive Interference Cancellation (PIC/SIC) strategy to a multicarrier (OFDMA/SC-FDMA) scheme. The algorithm details are analyzed and the PIC and SIC cancellation strategies are simulated and compared on random MIMO selective fading channels, considering limited complexities. The best PIC and SIC schemes for a given limited complexity (8 turbo decoding iterations per codeword) are compared for different codeblock lengths and spatial correlation scenarios over an EPA channel model. The 2 cycles SIC scheme shows the best performance over the selected scenarios, offering gains over the non-iterative schemes (measured at BLER values of 0.1) ranging from 1 to 4 dB in the considered cases. Larger gains are obtained with higher spatial correlation and shorter codeblock lengths. Better overall performance are obtained with lower spatial correlation and longer codeblock lengths

A Novel Single-Fed Dual-Band Dual-Circularly Polarized Dielectric Resonator Antenna for 5G Sub-6GHz Applications

In this research article, a single-fed dual-band circular polarized (CP) dielectric resonator antenna (DRA) for dual-function communication, such as GPS and WLAN, was made. Initially, the proposed design process was initiated by designing a linearly polarized singly fed-DRA. To attain CP fields, the cross-shape conformal metal strip was optimized to excite the fundamental and the high-order mode in the two frequency bands. The metallic strip (parasitic) was utilized on top of the rectangular DRA to improve and widen the impedance and axial ratio (AR) bandwidth. This step led to a 2.73% improvement on the lower band and an impact of 6.5% on the upper band while on the other side a significant improvement was witnessed in the AR bandwidth in both frequency bands. A prototype was designed and fabricated in order to validate its operations. The measurement outcomes of the proposed antennas authenticated wideband impedance bandwidths of 6.4% and 25.26%, and 3-dB axial ratios (AR) of 21.26% and 27.82% respectively. The prototype is a decent candidate for a global positioning system (GPS) and wireless local area network (WLAN).This project has received funding from the Universidad Carlos III de Madrid and the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska- Curie Grant 801538

BHPR research: qualitative1. Complex reasoning determines patients' perception of outcome following foot surgery in rheumatoid arhtritis

Background: Foot surgery is common in patients with RA but research into surgical outcomes is limited and conceptually flawed as current outcome measures lack face validity: to date no one has asked patients what is important to them. This study aimed to determine which factors are important to patients when evaluating the success of foot surgery in RA Methods: Semi structured interviews of RA patients who had undergone foot surgery were conducted and transcribed verbatim. Thematic analysis of interviews was conducted to explore issues that were important to patients. Results: 11 RA patients (9 ♂, mean age 59, dis dur = 22yrs, mean of 3 yrs post op) with mixed experiences of foot surgery were interviewed. Patients interpreted outcome in respect to a multitude of factors, frequently positive change in one aspect contrasted with negative opinions about another. Overall, four major themes emerged. Function: Functional ability & participation in valued activities were very important to patients. Walking ability was a key concern but patients interpreted levels of activity in light of other aspects of their disease, reflecting on change in functional ability more than overall level. Positive feelings of improved mobility were often moderated by negative self perception ("I mean, I still walk like a waddling duck”). Appearance: Appearance was important to almost all patients but perhaps the most complex theme of all. Physical appearance, foot shape, and footwear were closely interlinked, yet patients saw these as distinct separate concepts. Patients need to legitimize these feelings was clear and they frequently entered into a defensive repertoire ("it's not cosmetic surgery; it's something that's more important than that, you know?”). Clinician opinion: Surgeons' post operative evaluation of the procedure was very influential. The impact of this appraisal continued to affect patients' lasting impression irrespective of how the outcome compared to their initial goals ("when he'd done it ... he said that hasn't worked as good as he'd wanted to ... but the pain has gone”). Pain: Whilst pain was important to almost all patients, it appeared to be less important than the other themes. Pain was predominately raised when it influenced other themes, such as function; many still felt the need to legitimize their foot pain in order for health professionals to take it seriously ("in the end I went to my GP because it had happened a few times and I went to an orthopaedic surgeon who was quite dismissive of it, it was like what are you complaining about”). Conclusions: Patients interpret the outcome of foot surgery using a multitude of interrelated factors, particularly functional ability, appearance and surgeons' appraisal of the procedure. While pain was often noted, this appeared less important than other factors in the overall outcome of the surgery. Future research into foot surgery should incorporate the complexity of how patients determine their outcome Disclosure statement: All authors have declared no conflicts of interes

LDPC Coding for QKD at Higher Photon Flux Levels Based on Spatial Entanglement of Twin beams in PDC

Twin beams generated by Parametric Down Conversion (PDC) exhibit quantum correlations that has been effectively used as a tool for many applications including calibration of single photon detectors. By now, detection of multi-mode spatial correlations is a mature field and in principle, only depends on the transmission and detection efficiency of the devices and the channel. In [2, 4, 5], the authors utilized their know-how on almost perfect selection of modes of pairwise correlated entangled beams and the optimization of the noise reduction to below the shot-noise level, for absolute calibration of Charge Coupled Device (CCD) cameras. The same basic principle is currently being considered by the same authors for possible use in Quantum Key Distribution (QKD) [3, 1]. The main advantage in such an approach would be the ability to work with much higher photon fluxes than that of a single photon regime that is theoretically required for discrete variable QKD applications (in practice, very weak laser pulses with mean photon count below one are used).The natural setup of quantization of CCD detection area and subsequent measurement of the correlation statistic needed to detect the presence of the eavesdropper Eve, leads to a QKD channel model that is a Discrete Memoryless Channel (DMC) with a number of inputs and outputs that can be more than two (i.e., the channel is a multi-level DMC). This paper investigates the use of Low Density Parity Check (LDPC) codes for information reconciliation on the effective parallel channels associated with the multi-level DMC. The performance of such codes are shown to be close to the theoretical limits

FEC coding for QKD at higher photon flux levels based on spatial entanglement of twin beams in PDC

win beams generated by Parametric Down Conversion (PDC) exhibit quantum correlations that have been effectively used for calibration of single photon detectors and Charge Coupled Device (CCD) cameras [1]. The natural setup of quantization of CCD detection area and measurement of the correlation statistic needed to detect the presence of the eavesdropper Eve leads to a set of QKD parallel channel models that are non-binary Discrete Memoryless Channels (DMC). This work explores Forward Error Correction (FEC) coding for information reconciliation over the resulting parallel DMCs. [1] I. P. Degiovanni M. Genovese M.Gramegna A. Avella, G. Brida and P. Traina. Phys. Rev. A, 82:062309, 2010

Soft-metric based decoding for photon counting receivers

In [1] a low-complexity photon-counting receiver has been presented, which may be employed in long-distance amplification-free classical optical communication schemes, and which is typically modeled through its equivalent Binary Symmetric Channel (BSC) model. In this paper, we consider the scheme described in [1], but we model it as a time varying Binary Input-Multiple Output (BIMO) channel, and analyze its performance in presence of soft-metric based capacity approaching error correcting codes. We show that the classical channel capacity of the suggested BIMO model is higher than the capacity of the BSC model, and that the use of the BIMO model allows to feed the channel decoder with soft information, in the form of Log-Likelihood Ratios (LLRs), achieving a significant reduction in Bit Error Rate (BER) and Frame Error Rate (FER) with respect to classical hard-metric-based schemes which should be used in conjunction with a BSC channel mode