Bio


I am a general surgery resident at Stanford Hospital. I am interested in surgical health services research and access to and outcomes of surgical care in underserved populations, both in the US and abroad.

All Publications


  • The How Project: understanding contextual challenges to global surgical care provision in low-resource settings. BMJ global health Raykar, N. P., Yorlets, R. R., Liu, C., Goldman, R., Greenberg, S. L., Kotagal, M., Farmer, P. E., Meara, J. G., Roy, N., Gillies, R. D. 2016; 1 (4)

    Abstract

    5 billion people around the world do not have access to safe, affordable, timely surgical care. This series of qualitative interviews was launched by The Lancet Commission on Global Surgery (LCoGS) with the aim of understanding the contextual challenges-the specific circumstances-faced by surgical care providers in low-resource settings who care for impoverished patients, and how those providers overcome these challenges.From January 2014 to February 2015, 20 LCoGS collaborators conducted semistructured interviews with 148 surgical providers in low-resource settings in 21 countries. Stratified purposive sampling was used to include both rural and urban providers, and reputational case selection identified individuals. Interviewers were trained with an implementation manual. Following immersion into de-identified texts from completed interviews, topical coding and further analysis of coded texts was completed by an independent analyst with periodic validation from a second analyst.Providers described substantial financial, geographic and cultural barriers to patient access. Rural surgical teams reported a lack of a trained workforce and insufficient infrastructure, equipment, supplies and banked blood. Urban providers face overcrowding, exacerbated by minimal clinical and administrative support, and limited interhospital care coordination. Many providers across contexts identified national health policies that do not reflect the realities of resource-poor settings. Some findings were region-specific, such as weak patient-provider relationships and unreliable supply chains. In all settings, surgical teams have created workarounds to deliver care despite the challenges.While some differences exist between countries, the barriers to safe surgery and anaesthesia are overall consistent and resource-dependent. Efforts to advance and expand global surgery must address these commonalities, while local policymakers can tailor responses to key contextual differences.

    View details for DOI 10.1136/bmjgh-2016-000075

    View details for PubMedID 28588976

    View details for PubMedCentralID PMC5321373

  • A qualitative study exploring contextual challenges to surgical care provision in 21 LMICs. Lancet Raykar, N. P., Yorlets, R. R., Liu, C., Greenberg, S. L., Kotagal, M., Goldman, R., Roy, N., Meara, J. G., Gillies, R. D. 2015; 385: S15-?

    Abstract

    Billions of people worldwide are without access to safe, affordable, and timely surgical care. The Lancet Commission on Global Surgery (LCoGS) conducted a qualitative study to understand the contextual challenges to surgical care provision in low-income and middle-income countries (LMICs), and how providers overcome them.A semi-structured interview was administered to 143 care providers in 21 LMICs using stratified purposive sampling to include both urban and rural areas and reputational case selection to identify individual providers. Interviews were conducted in Argentina (n=5), Botswana (3), Brazil (10), Cape Verde (4), China (14), Colombia (4), Ecuador (6), Ethiopia (10), India (15), Indonesia (1), Mexico (9), Mongolia (4), Namibia (2), Pakistan (13), Peru (5), Philippines (1), Sierra Leone (11), Tanzania (5), Thailand (2), Uganda (9), and Zimbabwe (15). Local collaborators of LCoGS conducted interviews using a standardised implementation manual and interview guide. Questions revolved around challenges or barriers in the area of access to care for patients; challenges or barriers in the area of in-hospital care for patients; and challenges or barriers in the area of governance or health policy. De-identified interviews were coded and interpreted by an independent analyst.Providers across continent and context noted significant geographical, financial, and educational barriers to access. Surgical care provision in the rural hospital setting was hindered by a paucity of trained workforce, and inadequacies in basic infrastructure, equipment, supplies, and access to banked blood. In urban areas, providers face high patient volumes combined with staff shortages, minimal administrative support, and poor interhospital care coordination. At a policy level, providers identified regulations that were inconsistent with the realities of low-resource care provision (eg, a requirement to provide 'free' care to certain populations but without any guarantee for funding). Regional variation did exist on some matters, particularly related to prevalence of patient-provider mistrust and supply chain failures. Everywhere, providers have created innovative workarounds to overcome some of these barriers, such as clever financing mechanisms for planned surgery (eg, raising donated farm animals for cash in Zimbabwe, Ethiopia, and India), provision in scheduling and accommodations to facilitate patients from afar, reduction of cost and waste through re-sterilisation of disposable supplies, and locally sourcing consumables (eg, hand cleaning solution made of alcohol from the local distillery in India).Although some variation exists between countries, the challenges to surgical care provision are largely consistent and based on local resource availability; underfunded rural hospitals faced similar challenges worldwide. Global efforts to scale-up surgical services can focus on these commonalities (eg, investments in infrastructure, workforce), while local governments can tailor solutions to key contextual differences (eg, community-based outreach, supply chains, professional management, and interhospital coordination).None.

    View details for DOI 10.1016/S0140-6736(15)60810-8

    View details for PubMedID 26313061

  • Geospatial mapping to estimate timely access to surgical care in nine low-income and middle-income countries. Lancet Raykar, N. P., Bowder, A. N., Liu, C., Vega, M., Kim, J. H., Boye, G., Greenberg, S. L., Riesel, J. N., Gillies, R. D., Meara, J. G., Roy, N. 2015; 385: S16-?

    Abstract

    The Lancet Commission on Global Surgery calls for universal access to safe, affordable, and timely surgical care. Two requisite components of timely access are (1) the ability to reach a surgical provider in a given timeframe, and (2) the ability to receive appropriately prompt care from that provider. We chose a threshold of 2 h in view of its relevance in time-to-death in post-partum haemorrhage. Here, we use geospatial mapping to enumerate the percentage of a nation's population living within 2 h of a surgeon and the surgeon-to-population ratio for each provider.Geospatial mapping was used to identify the population living within a 2-h driving distance (access zone) of a health-care facility staffed by a surgeon. Surgeon locations were extracted from Ministries of Health, professional society databases, and published literature for countries which had available data. Data were reviewed by individuals knowledgeable of in-country distribution. Spatial distribution of providers was mapped with Google Maps engine. Access zones were constructed around every provider through estimation of driving times in Google Maps. The number of people living within zones was estimated with the Socioeconomic Data and Applications Center Population Estimation Service. Surgeon-to-population ratios were constructed for every individual access zone and averaged to report a single ratio.Results (% country's population living within an access zone; average surgeon:population ratio within all access zones) are reported for nine countries with available data: Somaliland (16·9%; 1:118 306), Botswana (31·0%; 1:64 635), Ethiopia (39·6%; 1:229 696), Rwanda (41·3%; 1:158 484), Namibia (43·4%; 1:69 385), Zimbabwe (54%; 1:148 292), Mongolia (55·5%; 1:10 500), Sierra Leone (70·3%; 1:106 742), and Pakistan (84·4%, 1:139 299). Surgeon-to-population ratios vary substantially even within countries; in Sierra Leone, urban access zones have a ratio of 1:45 058 and rural access zones have a ratio of 1:467 929.Surgical access is poor in many low-income and middle-income countries, even when using a narrow definition of surgical access consisting only of timeliness. Living outside of an access zone makes timely access to surgical care highly unlikely, and in view of low surgeon-to-population ratios and poor prehospital transport, even living within a 2-h access zone might not confer 2-h access. Investments in infrastructure and training must be prioritised to address widespread disparity in access to timely surgery.None.

    View details for DOI 10.1016/S0140-6736(15)60811-X

    View details for PubMedID 26313062

  • Hepatic Hydatid Cyst: A Rare Cause of Recurrent Pancreatitis JOURNAL OF GASTROINTESTINAL SURGERY Kitchens, W. H., Liu, C., Ryan, E. T., Fernandez-del Castillo, C. 2014; 18 (11): 2057-2059

    Abstract

    A case of pancreatitis secondary to a hepatic hydatid cyst is illustrated together with its preoperative imaging and intraoperative appearance. Cystobiliary communication is a common complication of large hydatid cysts, and episodes of recurrent pancreatitis resulting from passage of cyst contents down the biliary tract are rarely described. The clinical manifestations, diagnostic workup, and surgical management options of echinococcal-related pancreatitis are discussed, and a review of the literature is provided.

    View details for DOI 10.1007/s11605-014-2630-1

    View details for Web of Science ID 000343919700022

    View details for PubMedID 25149853

  • California Emergency Department Closures Are Associated With Increased Inpatient Mortality At Nearby Hospitals HEALTH AFFAIRS Liu, C., Srebotnjak, T., Hsia, R. Y. 2014; 33 (8): 1323-1329

    Abstract

    Between 1996 and 2009 the annual number of emergency department (ED) visits in the United States increased by 51 percent while the number of EDs nationwide decreased by 6 percent, which placed unprecedented strain on the nation's EDs. To investigate the effects of an ED's closing on surrounding communities, we identified all ED closures in California during the period 1999-2010 and examined their association with inpatient mortality rates at nearby hospitals. We found that one-quarter of hospital admissions in this period occurred near an ED closure and that these admissions had 5 percent higher odds of inpatient mortality than admissions not occurring near a closure. This association persisted whether we considered ED closures as affecting all future nearby admissions or only those occurring in the subsequent two years. These results suggest that ED closures have ripple effects on patient outcomes that should be considered when health systems and policy makers decide how to regulate ED closures.

    View details for DOI 10.1377/hlthaff.2013.1203

    View details for Web of Science ID 000340471700004

    View details for PubMedID 25092832

  • Indications, Hospital Course, and Complexity of Patients Undergoing Tracheostomy at a Tertiary Care Pediatric Hospital OTOLARYNGOLOGY-HEAD AND NECK SURGERY Liu, C., Heffernan, C., Saluja, S., Yuan, J., Paine, M., Oyemwense, N., Berry, J., Roberson, D. 2014; 151 (2): 232-239

    Abstract

    The purpose of this study was to review inpatients undergoing tracheostomies at a tertiary care pediatric hospital in a 24-month period and to identify the indications, comorbidities, hospital course, patient complexity, and predischarge planning for tracheostomy care. The goal was to analyze these factors to highlight potential areas for improvement.Case series with chart review.Tertiary care pediatric hospital.Ninety-five inpatients at Boston Children's Hospital requiring a primary or revision tracheostomy during the 24-month period encompassing 2010 to 2011.Inpatients undergoing tracheostomy during the study period were identified using 2 different databases: the Boston Children's Hospital Department of Otolaryngology and Communication Enhancement database and institution-specific information from the Child Health Corporation of America's Pediatric Health Information System (PHIS). We extracted the specified metrics from the inpatient charts.Patients undergoing tracheostomy are complex, with an average of 3.4 comorbidities and 13.6 services involved in their care. The tracheostomy was mentioned in 97.9% of physician and 69.5% of nurse discharge notes, and 42.5% of physician discharge notes contained a plan or appointment for follow-up. Of the patients, 33.7% were discharged home (27.3% of the nonanatomic group and 52.4% of the anatomic group). Overall, 8.4% of tracheostomy patients died before discharge.The complexity of pediatric tracheostomy patients presents challenges and opportunities for optimizing quality of care for these children. Future directions include the introduction and assessment of multidisciplinary tracheostomy care teams, tracheostomy nurse specialists, and tracheostomy care plans in the pediatric setting.

    View details for DOI 10.1177/0194599814531731

    View details for Web of Science ID 000340453300008

    View details for PubMedID 24788698

  • Decoupling catalytic activity from biological function of the ATPase that powers lipopolysaccharide transport PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Sherman, D. J., Lazarus, M. B., Murphy, L., Liu, C., Walker, S., Ruiz, N., Kahne, D. 2014; 111 (13): 4982-4987

    Abstract

    The cell surface of Gram-negative bacteria contains lipopolysaccharides (LPS), which provide a barrier against the entry of many antibiotics. LPS assembly involves a multiprotein LPS transport (Lpt) complex that spans from the cytoplasm to the outer membrane. In this complex, an unusual ATP-binding cassette transporter is thought to power the extraction of LPS from the outer leaflet of the cytoplasmic membrane and its transport across the cell envelope. We introduce changes into the nucleotide-binding domain, LptB, that inactivate transporter function in vivo. We characterize these residues using biochemical experiments combined with high-resolution crystal structures of LptB pre- and post-ATP hydrolysis and suggest a role for an active site residue in phosphate exit. We also identify a conserved residue that is not required for ATPase activity but is essential for interaction with the transmembrane components. Our studies establish the essentiality of ATP hydrolysis by LptB to power LPS transport in cells and suggest strategies to inhibit transporter function away from the LptB active site.

    View details for DOI 10.1073/pnas.1323516111

    View details for Web of Science ID 000333579700069

    View details for PubMedID 24639492