understanding and managing complications in neurosurgery

It is a well-known surgical maxim that only two types of surgeons do not have surgical complications; those who do not operate, and those who lie. Surgical complications in other words, are unwanted but undeniable part of surgery. There is not one operation with a 0% complication rate and therefore statistically, if a surgeon does not have complications, he probably has not operated enough. Despite their inevitability, complications convey a sense of gravity to the public, health professionals, and the policy makers alike

Self Adaptive Reinforcement Learning for High-Dimensional Stochastic Systems with Application to Robotic Control

A long standing goal in the field of artificial intelligence (AI) is to develop agents that can perceive richer problem space and effortlessly plan their activity in minimal duration. Several strides have been made towards this goal over the last few years due to simultaneous advances in compute power, optimized algorithms, and most importantly evident success of AI based machines in nearly every discipline. The progress has been especially rapid in area of reinforcement learning (RL) where computers can now plan-ahead their activities and outperform their human rivals in complex problem domains like chess or Go game. However, despite encouraging progress, most of the advances in RL-based planning still take place in deterministic context (e.g. constant grid size, known action sets, etc.) which does not adapts well to stochastic variations in problem domain. In this dissertation we develop techniques that enable self-adaptation of agent\u27s behavioral policy when exposed to variations in problem domain. In particular, first we introduce an initial model that loosely realizes problem domain\u27s characteristics. The domain characteristics are embedded into a common multi-modal embedding space set. The embedding space set then allows us to identify initial beliefs and establish prior distributions without being constrained to only finite collection of agent\u27s state-action-reward experiences to choose from. We describe a learning technique that adapts to variations in problem domain by retaining only salient features of preceding domains, and inferring posterior for newly introduced variation as direct perturbation to aggregated priors. Besides having theoretical guarantees, we demonstrate end-to-end solution by establishing FPGA-based recurrent neural network, that can change its synaptic architecture temporally, thus eliminating the need of maintaining dual networks. We argue that our hardware based neural implementation has practical benefits, due to the fact it only uses sparse network architecture and multiplex it on circuit level to exhibit recurrence, which can reduce inference latency on circuit-level, while maintaining equivalence to dense neural architecture

ARTERY FIRST TECHNIQUE FOR MANAGEMENT OF ABERRANT HEPATIC ARTERIAL ANATOMY DURING PANCREATICODUODENECTOMY-EXPERIENCE FROM A SPECIALIZED HEPATO-PANCREATO-BILIARY UNIT

Purpose: Aberrant hepatic arterial anatomy poses a challenge for surgeon during pancreaticoduodenectomy (PD). These anomalies are best picked up on pre-operative imaging to avoid inadvertent injury to the aberrant vasculature resulting in liver ischaemia or biliary-enteric anastomotic failure. We present our experience of dealing with aberrant hepatic vessels during PD. Methods: Patients with aberrant hepatic vasculature who underwent PD between September 2014 and August 2015 were included in the study. We used artery rst technique for dissection in cases identified on pre operative imaging. Aberrations were classed according to Hiatt classi cation. Results: A total of 23 PD were performed with aberrant arterial anatomy in 10 (43%) cases. These vessels were recognised and preserved in nine cases. In one patient, the replaced right hepatic artery (RRHA) arising from superior mesenteric artery (SMA) was coursing through pancreatic parenchyma needing resection and reconstruction with uneventful post-operative recovery. We also identified one RRHA arising from SMA coursing lateral to common bile duct and entering liver parenchyma in gallbladder fossa. Conclusion: Aberrant hepatic arterial anomalies are common and should ideally be picked up by pre-operative imaging. It is possible to preserve these vessels in most cases with careful surgical dissection using artery first technique. Surgeons performing PD should be well versed with the aberrant vascular anatomy to minimise any inadvertent damage. Key words: Aberrant hepatic artery, artery first technique, pancreaticoduodenectomy

SHORT TERM OUTCOME OF PATIENTS WITH HEPATOPANCREATOBILIARY MALIGNANCIES TREATED IN A MULTIDISCIPLINARY HEPATOBILIARY UNIT IN A TERTIARY REFERRAL CENTER

Purpose: Specialisation in hepatopancreatobiliary (HPB) surgery has evolved over the past few decades based on better understanding of the biology and the behaviour of the diseases. In this review from a specialised HPB service, we aim to provide an overview of the HPB oncological cases managed in a tertiary care cancer hospital. Methods: All cases of HPB malignancies treated in our hospital between October 2014 and September 2015 were included in the study. Clinical findings, operative details and short-term post-operative outcomes were assessed from a prospectively managed database. Results: A total of 65 oncological procedures were performed over 1 year. These included 23 hepatic resections, 27 pancreaticoduodenectomies, 5 radical surgeries for gallbladder cancer, 2 distal pancreatectomy and 8 nephrectomies with exploration of the inferior vena cava. One patient successfully underwent Associated Liver Partition with Portal vein ligation and staged hepatectomy (ALPPS Procedure), which to our knowledge was the rst ALPPS procedure carried out in Pakistan. Conclusion: The short-term experience of patients managed in specialised HPB unit has shown good outcomes.There is a need for establishing HPB units in most tertiary care hospitals in the country. Key words: Associated liver partition with portal vein ligation and staged hepatectomy procedure, hepatic resections, hepatopancreatobiliary surgery, pancreaticoduodenectomy

PHYLLOIDES TUMOUR: REVIEW OF AN UNCOMMON BREAST PATHOLOGY AT A SPECIALIZED CANCER CENTRE

Purpose: Phyllodes tumours are rare breast tumours that comprise almost 1% of breast tumours. The outcome for these tumours is generally considered better than breast cancers. We review the cases of phyllodes tumour presenting to a specialised cancer centre over a 14 year period. Materials and Methods: All case records with the diagnosis of phyllodes tumour between 1999 and 2012 were retrieved from the cancer registry. Patient demographics, tumour site, size, axillary lymph node status, whether primary or recurrent, metastatic status, histological type, type of surgery, any complication, margin positivity, post-operative radiation therapy, local or distant recurrence, morality and follow-up duration were recorded. Data were analysed using SPSS. Results: A total of 77 cases of phyllodes tumour were seen between 1999 and 2012. All patients were female with a mean age of 39.9 years. All patients presented with a breast lump with median duration of 8 months. Almost two-thirds (65%) of the patients presented with primary tumour compared to 10% recurrent tumours and the rest were referred after surgery outside. Median size on histopathology was 5 cm (IQR 3.5–8.5 cm). Over a median follow-up duration of 31 months (IQR 9–48 months), 69 patients (89.6%) were alive, while 3 patients (3.9%) did not survive and 5 patients (6.4%) were lost to follow-up. Recurrence was seen in 10 (13%) patients with median time to recurrence of 12 months (IQR 7–24). Involved axillary lymph nodes and borderline or malignant histopathology were found to be signi cantly associated with recurrence (P = 0.04), while margin positivity, post operative radiation therapy and histopathology were not signi cantly associated with recurrence. Conclusion: Phyllodes tumour is an uncommon breast tumour that is predominantly treated with surgical excision. Although survival with these tumours is better compared to breast cancers, involvement of axillary nodes and borderline or malignant histopathology confer an increased risk of recurrence in these patients. Key words: Breast cancer, phyllodes tumours, survival

Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study

We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05-1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4-7 days or >= 8 days of 1.25 (1.04-1.48), p = 0.015 and 1.31 (1.11-1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care

Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery

Peer reviewe

Postoperative outcomes in oesophagectomy with trainee involvement

BACKGROUND: The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting. METHODS: Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups. RESULTS: Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005). CONCLUSION: Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery