Contemporary Outcomes of Grade-C Postoperative Pancreatic Fistula in a Nationwide Database

INTRODUCTION

Grade-C postoperative pancreatic fistulas (POPFs) are dreaded complications following pancreaticoduodenectomy. The aim of this study was to quantify the incidence and risk factors associated with grade C POPF in a national database.

METHODS

The National Surgical Quality Improvement Program targeted user files were queried for patients who underwent elective pancreaticoduodenectomy (2014-2020). Outcomes were compared between clinically relevant (CR) grade B POPF and grade C POPF.

RESULTS

Twenty-six thousand five hundred fifty-two patients were included, of which 90.1% (n = 23,714) had No CR POPF, 8.7% (n = 2287) suffered grade B POPF, and 1.2% (n = 327) suffered grade C POPF. There was no change in the rate Grade-C fistula overtime (m = 0.06, P = 0.63), while the rate of Grade-B fistula significantly increased (m = +1.40, P < 0.01). Fistula Risk Scores were similar between grade B and C POPFs (high risk: 34.9% versus 31.2%, P = 0.21). Associated morbidity was increased with grade C POPF, including delayed gastric emptying, organ space infections, wound dehiscence, respiratory complications, renal complications, myocardial infarction, and bleeding. On multivariate logistic regression, diabetes mellitus (odds ratio: 1.41 95% confidence interval: 1.06-1.87, P = 0.02) was associated with grade C POPF.

CONCLUSIONS

This study represents the largest contemporary series evaluating grade C POPFs. Of those suffering CR POPF, the presence of diabetes mellitus was associated with grade C POPF. While modern management has led to grade C POPF in 1% of cases, they remain associated with alarmingly high morbidity and mortality, requiring further mitigation strategies to improve outcomes.

247 QUALITY IMPROVEMENT IN DEMENTIA CARE: STREAMLINING CARE PATHWAYS IN A PSYCHIATRY OF OLD AGE SERVICE

Background

Dementia is increasingly considered a public health priority worldwide in the context of predicted increased prevalence. In Ireland, there are an estimated 67,000 persons living with dementia and by 2041 it is expected to rise to 145,000 persons. Challenges in dementia care have been highlighted in health services across Europe and the ineffective structure of dementia care with fragmented non-person-centred pathways has been identified.

Methods

An initial review of the existing cognitive impairment diagnostic pathways in our specialised Psychiatry of Old Age (POA) Service was undertaken. This included surveying the multidisciplinary team to identify challenges, clinical chart review and audit of physical examination equipment. Diagnostic pathway was updated based on findings and informed by the developing national ‘Model of Care for Dementia in Ireland’ and best practice.

Results

Review findings included lack of standardisation of memory assessment, delays in accessing neuroimaging and laboratory results, gaps in staff training. A care pathway document was developed detailing requirements for care from the point of referral through to cognitive impairment diagnosis. Staff training was completed to accompany the introduction of standardised dementia assessment scales. Access to laboratory/radiology booking was enhanced. A cognitive remediation group was developed by Occupational Therapy as part of post-diagnostic supports for service users. Preliminary data indicates improvements in satisfaction of those attending the group. Physical examination equipment audit resulted in quality improvements.

Conclusion

We demonstrate that a quality improvement approach can be implemented to enhance assessment, diagnosis and care provided to support diagnosis of cognitive impairment and dementia in POA service. The enhanced diagnostic care pathways will be assessed over time to assess impact on care of service users. Preliminary findings are positive and it is an approach that can be adopted in other services and inform development of national memory service developments.

Opportunity Costs of Surgical Resection and Perioperative Chemotherapy for Locoregional Pancreatic Adenocarcinoma

PURPOSE

Given the perioperative morbidity and intensity of multimodality treatment, patients with resected pancreatic ductal adenocarcinoma (PDAC) spend a substantial amount of time in clinical care. The primary aim was to determine total time spent in multimodality care for patients with locoregional PDAC.

METHODS

A cohort study of all patients who underwent curative-intent resection for PDAC at a single-institution, tertiary care center was performed (2015-2019). Exact times for all relevant visits were abstracted from the primary medical record, and travel time was calculated. Care time was divided into preoperative, surgical, radiation, and systemic therapy phases of care. Primary outcome measures were the percentage of total survival time (TST) and percentage of overall survival (OS) days spent in receipt of care.

RESULTS

One hundred seven patients were included. Patients spent a median of 5.0% (interquartile range [IQR] 2.4%-10.1%) of TST and 11.0% (IQR, 5.7%-20.4%) of OS days in receipt of clinical care. Preoperative, surgical, radiation, and systemic therapy phases of care comprised a median of 0.9% (IQR, 0.4%-2.2%), 3.0% (IQR, 1.9%-6.8%), 4.4% (IQR, 3.6%-6.3%), and 10.0% (IQR, 6.2%-14.1%) of OS days. The median per-visit travel time was 60 minutes (IQR, 32-120), and the median cumulative travel time was 22.0 hours (IQR, 12.0-51.5). 12.1% (n = 13) and 7.8% (n = 4) of patients spent > 10% of TST in receipt of surgical and systemic therapy care, respectively.

CONCLUSION

Patients with locoregional pancreatic cancer spend a considerable percentage of their survival time in receipt of oncologic care. Further research to determine predictors of increased time burden is warranted to better inform shared decision making.

Neuroscience Near-Peer-Led Flipped Classroom Improves Student Confidence With Clinical Application of Content and Test-Taking Skills

INTRODUCTION

The ability to apply knowledge gained in neuroscience coursework to a clinical scenario is found to be difficult by many medical students. Neuroscience is both important for future clinical practice and an area frequently tested on USMLE Step 1 examinations.

METHODS

Second-year medical students created a peer-led flipped classroom to help first-year students practice applying medical neuroscience course information to clinical situations and demonstrate how that information might be tested in board-style questions. The second-year students designed a series of board-style questions that included explanations for both the correct and incorrect answers. We divided the first-year students (n = 80) into small groups during the flipped classroom sessions, where they were led by second-year medical students in discussion about the questions and clinical situations.

RESULTS

Students reported agreement that the session addressed gaps in their knowledge and provided them with useful critical thinking skills for approaching board-style questions (83% and 81% agreed or strongly agreed, respectively).

DISCUSSION

The flipped classroom improved student confidence in both applying neuroscience concepts to clinical scenarios and to board-style vignette questions.

Opportunity costs of undergoing surgical resection and perioperative chemotherapy for pancreatic adenocarcinoma

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Background: Treatment of early stage pancreatic ductal adenocarcinoma (PDAC) includes surgical resection and either neoadjuvant or adjuvant chemotherapy. Due to the intensity of treatment and perioperative morbidity rates of pancreatic resection, patients may spend a significant portion of their survival time in receipt of clinical care. However, time spent in receipt of care has not been previously described in patients with early stage PDAC. The primary aim of this study was to determine the total time spent in receipt of surgical and perioperative chemotherapy in patients with resectable PDAC. Methods: A retrospective cohort study was performed of patients diagnosed with PDAC who underwent curative-intent resection at a single institution tertiary care center between January 2015 and October 2019. Patients who died within 30 days of surgery were excluded. Total care time, including all relevant clinician visits, laboratory, radiologic and procedural studies, and treatment visits, was abstracted from the primary medical record. Care time included estimated travel time based on patient address. Care time was divided into preoperative, surgical, and systemic therapy phases of care. Time spent in surgical care included the hospital length of stay, postoperative follow-up visits, and admissions for postoperative complications. Results: A total of 86 patients were identified. Median total preoperative care time was 29 hours (IQR 11-135; 0.4% of survival time, range 0% - 72.7%). Median total time spent in surgical care was 216 hours (IQR 164-371; 2% of survival time, range 0.3% - 68.4%). Among the patients who received systemic chemotherapy care within the same institutional health system (N = 41), median total time spent in receipt of systemic therapy was 447 hours (IQR 194-647; 3% of survival time, range 0.1% - 55.4%). 10.5% of patients (N = 9) spent more than 10% of total survival time in surgical care and 5.8% (N = 5) patients spent more than 10% of survival time in receipt of systemic care. Median cumulative travel time for patients was 19 hours (IQR 10.2-37.6). Conclusions: For the majority of patients undergoing resection for PDAC, time spent in receipt of surgical care does not appear to represent a substantial time burden relative to survival time. However, for a subset of patients, the time burden is considerable. Further research to determine predictors of increased time spent in receipt of multimodality cancer care is warranted to better inform patient and surgeon communication and decision-making.

Long-Range GABAergic Inputs Regulate Neural Stem Cell Quiescence and Control Adult Hippocampal Neurogenesis

The quiescence of adult neural stem cells (NSCs) is regulated by local parvalbumin (PV) interneurons within the dentate gyrus (DG). Little is known about how local PV interneurons communicate with distal brain regions to regulate NSCs and hippocampal neurogenesis. Here, we identify GABAergic projection neurons from the medial septum (MS) as the major afferents to dentate PV interneurons. Surprisingly, dentate PV interneurons are depolarized by GABA signaling, which is in sharp contrast to most mature neurons hyperpolarized by GABA. Functionally, these long-range GABAergic inputs are necessary and sufficient to maintain adult NSC quiescence and ablating them leads to NSC activation and subsequent depletion of the NSC pool. Taken together, these findings delineate a GABAergic network involving long-range GABAergic projection neurons and local PV interneurons that couples dynamic brain activity to the neurogenic niche in controlling NSC quiescence and hippocampal neurogenesis.

An Adeno-Associated Virus-Based Toolkit for Preferential Targeting and Manipulating Quiescent Neural Stem Cells in the Adult Hippocampus

Quiescent neural stem cells (qNSCs) with radial morphology are the only proven source of new neurons in the adult mammalian brain. Our understanding of the roles of newly generated neurons depends on the ability to target and manipulate adult qNSCs. Although various strategies have been developed to target and manipulate adult hippocampal qNSCs, they often suffer from prolonged breeding, low recombination efficiency, and non-specific labeling. Therefore, developing a readily manufactured viral vector that allows flexible packaging and robust expression of various transgenes in qNSCs is a pressing need. Here, we report a recombinant adeno-associated virus serotype 4 (rAAV4)-based toolkit that preferentially targets hippocampal qNSCs and allows for lineage tracing, functional analyses, and activity manipulation of adult qNSCs. Importantly, targeting qNSCs in a non-Cre-dependent fashion opens the possibility for studying qNSCs in less genetically tractable animal species and may have translational impact in gene therapy by preferentially targeting qNSCs.

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rAAV4 vectors preferentially target quiescent NSCs in the adult hippocampus

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rAAV4 vectors with distinct promoters reveal differential selectivity for radial NSCs

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rAAV4 allows for genetic manipulation and lineage tracing of quiescent NSCs

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rAAV4 allows for calcium imaging and activity manipulation of quiescent NSCs

Lhx6-positive GABA-releasing neurons of the zona incerta promote sleep

Multiple populations of wake-promoting neurons have been characterized in mammals, but few sleep-promoting neurons have been identified. Wake-promoting cell types include hypocretin and GABA (γ-aminobutyric-acid)-releasing neurons of the lateral hypothalamus, which promote the transition to wakefulness from non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. Here we show that a subset of GABAergic neurons in the mouse ventral zona incerta, which express the LIM homeodomain factor Lhx6 and are activated by sleep pressure, both directly inhibit wake-active hypocretin and GABAergic cells in the lateral hypothalamus and receive inputs from multiple sleep-wake-regulating neurons. Conditional deletion of Lhx6 from the developing diencephalon leads to decreases in both NREM and REM sleep. Furthermore, selective activation and inhibition of Lhx6-positive neurons in the ventral zona incerta bidirectionally regulate sleep time in adult mice, in part through hypocretin-dependent mechanisms. These studies identify a GABAergic subpopulation of neurons in the ventral zona incerta that promote sleep.

Optic neuritis in Singapore

INTRODUCTION

Optic neuritis (ON) is the commonest optic neuropathy encountered in the younger group of patients from the Singapore Neuro-Ophthalmology Study Group. Previous surveys in Asia and our study suggest that ON in Singapore differs from that in Western populations where the majority of cases are associated with multiple sclerosis (MS).

METHODS

Patients satisfying our entry criteria for ON seen between September 2002 and June 2004 were enrolled in the study. The data collected was recorded in a central database and analysed two years later.

RESULTS

The majority (60 percent) of our patients had anterior ON with optic disc swelling (papillitis), were idiopathic in 49.1 percent, and associated with MS in only 25.5 percent. Bilateral cases comprised 16.4 percent of our series and were usually of the anterior variety and mostly idiopathic, although it is still essential to rule out secondary causes. Recurrent ON is indicative of an underlying disease process.

CONCLUSION

The pattern of ON as seen in Singapore differs from that reported in Caucasian studies and from the seminal Optic Neuritis Treatment Trial. We found a higher incidence of optic disc swelling, i.e. anterior ON (papillitis), and a lesser association with MS; visual recovery is similarly good but our recurrence rate is lower.

Clinics in diagnostic imaging (120). Right rhinogenic optic neuritis secondary to mucocoele of the Onodi cell

Acute visual loss can be caused by retrobulbar optic neuritis, radiation optic neuropathy or ischaemic optic neuropathy. Sinusitis affecting the Onodi cell, a posterior ethmoidal air cell that has encroached on the adjacent sphenoid bone forming the optic canal, can present rarely with visual loss. We report a 60-year-old man, who developed a sudden ache on the nasal aspect of his right eye, and deterioration of the vision in his right eye. This case illustrates the typical radiological appearances of the Onodi cell on MR imaging and CT. The diagnosis of right rhinogenic optic neuritis secondary to mucocoele of the Onodi cell was confirmed at surgery. Functional endoscopic sinus surgery with decompression of the Onodi cell was performed. Physicians should be familiar with the presentation, performed. Physicians should be familiar with the presentation, diagnosis and management of this rare but important condition.

Polyurethane/poly(lactic-co-glycolic) acid composite scaffolds fabricated by thermally induced phase separation

In this study, we present a novel composite scaffold fabricated using a thermally induced phase separation (TIPS) process from poly(lactic-co-glycolic) (PLGA) and biomedical polyurethane (PU). This processing method has been tuned to allow intimate (molecular) mixing of these two very different polymers, giving rise to a unique morphology that can be manipulated by controlling the phase separation behaviour of an initially homogenous polymer solution. Pure PLGA scaffolds possessed a smooth, directional fibrous sheet-like structure with pore sizes of 0.1-200mum, a porous Young's modulus of 93.5kPa and were relatively brittle to touch. Pure PU scaffolds had an isotropic emulsion-like structure, a porous Young's modulus of 15.7kPa and were much more elastic than the PLGA scaffolds. The composite PLGA/PU scaffold exhibits advantageous morphological, mechanical and cell adhesion and growth supporting properties, when compared with scaffolds fabricated from PLGA or PU alone. This novel method provides a mechanism for the formation of tailored bioactive scaffolds from nominally incompatible polymers, representing a significant step forward in scaffold processing for tissue-engineering applications.

The presentation, aetiology, management and outcome of optic neuritis in an Asian population

PURPOSE

To analyse the presentation, aetiology, management and outcome of patients with optic neuritis (ON) in Singapore.

METHODS

This was a retrospective study involving consecutive patients with ON presentng at the Singapore National Eye Centre between January 1997 and May 1999. The presenting features, investigatons, treatment and visual outcome after 6 months were studied.

RESULTS

A total of 31 patents (39 eyes) presented with ON during this period, 17 of whom had anterior ON. No aetiology was found in 26 patients (83.9%), two patients (6.5%) had multiple sclerosis, one had active syphilis, one had rheumatoid arthritis and another had pan-sinusitis. Seventeen patients (54.8%) were treated with intravenous methyl-prednisolone followed by oral prednisolone. Within the follow-up period 26 of 31 eyes (83.9%) wth idiopathic ON attained visual acuity of 6/12 or better with 12 (38.7%) recovering to 6/6 or better and only one eye ending with less than 6/60 visual acuity. The one patient with syphilis recovered 6/6 visual acuity bilaterally. Both patients with multiple sclerosis also had good visual recovery at 6 months. The visual outcome in those cases of ON associated with rheumatoid arthritis and pan-sinusitis was poor with visual acuity of less than 6/60 at 6 months follow up in each instance.

CONCLUSION

The majority of the cases of ON in this study were idiopathic. There was a low association with multiple sclerosis. Most patients had good visual recovery within 6 months.

Ophthalmic manifestations in human immunodeficiency virus infection in Singapore

The paper retrospectively reviews the spectrum of ophthalmic manifestations in human immunodeficiency virus (HIV) infection in Singapore between May 1995 and October 1996. One hundred and eighteen patients were examined for ocular abnormalities. Criteria for examination were 1) visual complaints, 2) absolute CD4 count of less than 50 cells/ul, 3) patients with acquired immunodeficiency syndrome-defining illness or 4) any relevant systemic illnesses which may have ocular involvement. Only 25 patients (21.2%) had visual symptoms. Eighteen patients (15.3%) had abnormalities associated with microvasculature. Forty-four patients (37.3%) had opportunistic infection involving the eye of which 37 were that of cytomegalovirus retinitis (CMVR). Seven patients (5.9%) had neuro-ophthalmic disorders. One patient presented with proptosis due to orbital lymphoma. Four patients (3.4%) had episcleritis and 3 patients (2.5%) had symptomatic dry eyes. It is still not known if episcleritis and dry eyes are associated with HIV infection or are coincidental. Fifty-one patients (43.2%) had no ocular pathology and remained so throughout the period of study. Nine patients (7.6%) had more than one pathology. The major cause of visual loss was due to ocular infections, with CMVR being most prevalent. Recognising the ophthalmic signs in HIV patients will facilitate early diagnosis. Prompt treatment of eye involvement can prevent or delay blindness, which is psychologically and functionally important to these patients.