2022 Scholarship Abstracts

Annual Research Scholarship Competition


Outcomes and their State-Level Variation in Patients Undergoing Surgery with Perioperative SARS-CoV-2 Infection in the USA: A Prospective Multicenter Study

Osaid Alser, MD, MSc (Oxon), General Surgery Resident, Texas Tech University Health Sciences Center, Lubbock, TX

Uncertainty regarding the postoperative risks of patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exists. Therefore, we aimed to report the 30-day outcomes of patients with perioperative SARS-CoV-2 infection undergoing surgery in the USA.

As part of the COVIDSurg multicenter study, all patients aged ≥17 years undergoing surgery between January 1 and June 30, 2020 with perioperative SARS-CoV-2 infection in 70 hospitals across 27 states were included. The primary outcomes were 30-day mortality and pulmonary complications. Multivariable analyses (adjusting for demographics, comorbidities, and procedure characteristics) were performed to identify predictors of mortality.

A total of 1,581 patients were included; more than half of them were males (n= 822, 52.0%) and older than 50 years (n=835, 52.8%). Most procedures (n=1,261, 79.8%) were emergent, and laparotomies (n= 538, 34.1%). The mortality and pulmonary complication rates were 11.0 and 39.5%, respectively. Independent predictors of mortality included age ≥70 years (OR 2.46, 95% CI [1.65-3.69]), male sex (2.26 [1.53-3.35]), ASA grades 3-5 (3.08 [1.60-5.95]), emergent surgery (2.44 [1.31-4.54]), malignancy (2.97 [1.58-5.57]), respiratory comorbidities (2.08 [1.30-3.32]), and higher Revised Cardiac Risk Index (1.20 [1.02-1.41]). While statewide elective cancelation orders were not associated with a lower mortality, a sub-analysis showed it to be associated with lower mortality in those who underwent elective surgery (0.14 [0.03-0.61]).

Patients with perioperative SARS-CoV-2 infection in the United States have a significantly high risk for postoperative complications, especially elderly males. Postponing non-emergent surgery and adopting non-operative management, when reasonable, should be considered in the USA during the pandemic peaks.

Other participants in alphabetical order...

Chlorhexidine Gluconate Wound Irrigation and Surgical Site Infections in Renal Transplant Patient

Michael Burt, MD, General Surgery Resident, University of South Dakota, Sioux Falls, SD

Healthcare associated infections remain a common complication of inpatient hospital care. Among surgical patients, surgical site infections (SSI) are the most common hospital-acquired infection and are associated with increased length of stay, morbidity, and mortality. This is especially true in immunocompromised patients.  SSIs remain a challenging problem for renal transplant patients with incidence rates ranging from 5-20%. In this population SSIs are associated with significant morbidity in including graft failure and may increase risk of mortality. Chlorhexidine gluconate (CHG) 0.05% containing solution used as an intraoperative subcutaneous wound irrigation has been proposed as a possible intervention to reduce the risk of SSI.  Previous studies have been performed in a variety of patient populations and have demonstrated possible benefit of this intervention on reducing SSI rates. To date, there have been no prior studies specifically evaluating the efficacy of wound irrigation with CHG solution in prevention of SSI in renal transplant patients.

This study is a single center, single surgeon, retrospective analysis of patients who received either a deceased or living donor renal transplant at our institution within the last 10 years. SSI rates within 30 days of operation were compared between patients who received 0.05% CHG irrigation solution versus standard subcutaneous irrigation with warm saline.

Preliminary analysis of 95 renal transplant patients demonstrates overall SSI rate of 15.7% consistent with current literature. SSI rate in non-CHG saline irrigation patients was 19.6% (10/51) versus 11.4% (5/44) in the CHG irrigation group. Final analysis, matching, and results to be presented at conference.

Intraoperative subcutaneous incisional irrigation with CHG containing solution may be associated with decreased rates of SSI in renal transplant patients and should be further investigated by prospective randomized clinical trials.


Abdominal Perforation as a Complication of Tocilizumab use  in COVID-19 positive patients

Maaria Chaudhry, BS, Saint Louis University, New Castle, DE

The purpose will be to examine a specific case of abdominal perforation in an a COVID+ patient treated with Tocilizumab. There have been few recorded cases looking at the relationship between  tocilizumab  use in COVID+ patient and abdominal perforation.

This patient was examined upon admission, treatment and followup. He was initially prescribed tocilizumab.  However, he soon developed bilateral lower abdominal fullness and subcutaneous emphysema; a CT of the abdomen was ordered. It showed diffuse colonopathy of sigmoid colon with a large amount of extraluminal air and fluid in the left retroperitoneum, tracking through the left perirenal space into the left upper quadrant abdomen. He underwent CT guided drainage of pelvic abscess.  He then underwent an anterior resection, diverting loop ileostomy, open appendectomy, drainage of pelvic accesses, omental pedicle flap, and Jackson-Pratt drain placement.  He was transferred to the SICU post operatively due to a loss of blood (around 400 ccs) and then was taken into surgery to for exploratory laparotomy to control the hemorrhage from inferior mesenteric artery stump.

The patient ultimately recovered and was sent home.

If a seriously ill COVID-19 patient receives Tocilizumab and suffers from either persistent abdominal pain or new-onset subcutaneous emphysema, then gastrointestinal perforation needs to be ruled out.


A SIR Mathematical Model of Previous COVID-19 Strains to Analyze Delta Variant Spread

Alexandra Close, Student, University of Maryland, College Park, Olney, MD

The SIR Model has previously been used to model epidemics, and in the past year has been applied to the SARS-CoV-2 COVID-19 outbreak in various geographical areas.  Given the virulent transmissibility of the current Delta strain, understanding the impact of containment measures is pertinent. In this paper we focus on Miami-Dade, Florida, where robust data is available and where containment measures have evolved from one outbreak to the next. Using the SIR model to compare containment strategies between the Wuhan, Alpha, and Delta strains will allow us to conclude that better preventative measures would be beneficial in tempering another variant outbreak.

We propose to use the SIR Model to gauge the effectiveness of containment measures against the initial strains of the SARS-CoV-2 (Wuhan and Alpha strain) outbreaks by creating a hypothetical "worst-case" scenario with no interventions (β  = 2, γ = 1/14, N = 2,717,000). We then analyzed the Delta (B.1.617.2.) variant in Miami-Dade, Florida. We used official transmission and recovery rate parameters for the original SARS-CoV-2 strand and compared them against those yielded from data collected from the Johns Hopkins University COVID-19 database (Ensheng Donga, 2020). Assumptions made from this comparison were applied to our prediction for the Delta variant spike, where we assessed how containment measures and vaccinations may be influencing the SIR parameters.

We found that the SIR Model is still a useful tool in analyzing COVID-19 outbreaks and insights can be found regarding the quality of intervention strategies. From the modelling, we saw that strict containment measures used for the first peak were the most effective. While the transmission rate improved between the Wuhan and Alpha outbreaks, the size of the susceptible population increased by a proportion of 15. We attributed this to the lessening of previous restrictions that allowed for closer contact between infected and susceptible populations for the Alpha outbreak. When restrictions were reapplied to contain the second peak (Alpha) on July 2nd, it initiated a decline in cases 12 days later. Our model implied that the Delta outbreak was significantly worse, in rate of transmission (β = 0.87) and susceptible population (N = 60,000), than the Wuhan strain (β = 0.5, N = 750). The susceptible population of the Delta variant was five times that of the Alpha variant (N = 11,000), even though vaccination rates rose by 20%. These parameters were still far lower than that of the “worst-case scenario”, meaning that the containment measures used in all cases were successful but not necessarily optimal.

The SIR Model is a useful tool in epidemiologically monitoring a pandemic. Our modelling validates the importance of intensive containment measures in any highly contagious epidemic.


Outcomes and Efficacy of MRI-compatible Sacral Nerve Stimulator for Management of Fecal Incontinence

Binit Katuwal, MD, Surgery Resident, Providence Hospital, Royal Oak, MI

Fecal incontinence (FI) is an involuntary passage of fecal matter due to an inability to control the discharge of bowel contents. It can have a significant impact on patient’s quality of life. The InterStim was limited by MRI incompatibility. Given the increased need of MRI for diagnostics, MRI compatible InterStim was needed for widespread usage. Medtronic MRI compatible InterStim was FDA-approved in August 2020. Given the recent FDA approval, no large data or literature exists. This is the first study of pooled multi-institutional data to study the efficacy, outcomes and complications of the MRI compatible Interstim.

Pooled data of patients who underwent MRI compatible Interstim placement at UPMC WIlliamsport, University of Minnesota, University of Illinois, University of Wisconsin-Madison was analyzed which involved multiple surgeons and evaluated for the patient details, techniques, complications and outcomes.

A total of 73 patients underwent the implantation. Mean age of patients was 63.29±12.2 years, 57 (78.1%) were females. 42(57.5%) were diabetics. All had fecal incontinence, 23.3% had additional diarrhea, fecal urgency in 58.9% and concomitant urinary incontinence in 21(28.8%). N = 15 (20.5%) underwent Peripheral Nerve Evaluation (PNE) before implant. 32(43.8%) underwent rechargeable Interstim placement. 3(4.1%) had their implants removed. External lead connection migration was observed in 7(9.6%) patients after stage I procedure. Following this, a change in technique was done and recommended by Medtronic that the lead be secured to subcutaneous tissue. 1 patient had infection and implant was removed. 7(9.6%) had complications which included nerve pain, hematoma, infection, lead fracture and bleeding. Mean follow up was 6.62±3.5 months. During follow up, 68(93.2%) reported significant improvement of symptoms.

This study being the first to evaluate the MRI compatible Interstim shows promising results with significant symptom improvement, good efficacy, good patient outcomes with low complication rates in patients with FI. Further long-term follow-up and future studies with larger patient population is recommended.


Mortality Risk Factors in Patients Admitted with Tracheostomy Complications

Lior Levy, BA, New York Medical College, Valhalla, NY

Purpose: Tracheostomy is a procedure commonly conducted in patients undergoing emergency admission and require prolonged mechanical ventilation. In the present study, the aim was to determine the prevalence and risk factors of mortality among emergently admitted patients with tracheostomy complications, during the years 2005-2014.

Methods: This was a retrospective cohort study. Demographics and clinical data were obtained from the National Inpatient Sample, 2005-2014, to evaluate elderly (65+ years) and non-elderly adult patients (18-64 years) with tracheostomy complications (ICD-9 code 519) who underwent emergency admission. Multivariable generalized additive model and multivariable logistic regression model with backward elimination were used to identify association of predictors and in-hospital mortality.

Results: A total of 4,711 non-elderly and 3,315 elderly patients were included. Females included 44.5% of the non-elderly patients and 47.6% of the elderly patients. 181 (3.8%) non-elderly died of which 48% were female and 163 (4.9%) elderly died, of which 48% were female. The mean (SD) age of the non-elderly patients was 49.62 (12) years old and elderly patients was 74.30 (7) years old. The mean (SD) age at the time of death of non-elderly patients was 53.36 (9) years old and for elderly patients 75.32 (7) years old. In adults and elderly patient groups, 1,348 and 737 were operated on, respectively. Mean (SD) HLOS in adult patients was 9.51 (14.17) days in patients who had operation vs. 5.46 (7.70) days in those who did not (P<0.001). In elderly patients, mean (SD) HLOS was 9.07 (10.49) days in patients who had operation vs. 5.81 (7.70) in patients who did not (P<0.001). In the final multivariable regression model for patients with operation, time to operation, age and modified frailty index score stayed in the model but none of them were significant whereas time to operation (OR=1.068, 95%CI: 1.019-1.119, p=0.006) was the principle risk factor for elderly. In the final multivariable regression model for patients with no operation, hospital length of stay (OR=1.022, 95%CI: 1.008-1.036, p=0.003) and age (OR=1.032, 95%CI: 1.013-1.151, p=0.001) were the main risk factors of mortality in adults whereas only hospital length of stay (OR=1.028, 95%CI: 1.012-1.045, p=0.001) was the risk factor for elderly. Application of an invasive diagnostic procedure (OR=0.557, 95%CI: 0.356-0.870, p=0.01) was a protective factor for adults who did not undergo an operation.

Conclusions: Delayed operation was a significant risk factor of mortality for elderly patients who were operated on. Every day delay in time to operation in elderly patients that were operated on, increased the odds of mortality by 6.8% in elderly. Increased length of stay was a significant risk factor of mortality for all patients who were not operated on. Every day of longer stay in hospital in patients that were not operated on, increased the odds of mortality by 2.2% in adults and 2.8% in elderly.


Mortality in GI Adhesions with Obstruction: A 10-year Study of 115,012 Patients

Akash Thaker, MS, Medical Student, New York Medical College, Valhalla, NY

Patients admitted emergently for obstructions caused by intraabdominal adhesions have high rates of complications, including morbidity and mortality. The goal of our study was to assess risk factors associated with in-hospital mortality for patients with the primary diagnosis of intestinal or peritoneal adhesions with obstruction.

Emergently admitted patients with the primary diagnosis of intestinal or peritoneal adhesions with obstruction were analyzed using the National Inpatient Sample database, 2005-2014. Demographics, clinical data, and outcome were gathered for the current retrospective cohort study. The relationship between mortality and the predictors was assessed using stratified analysis and backward elimination multivariable logistic regression model. Odds ratios (ORs) and the corresponding 95% confidence intervals (95% CIs) were used to present the findings of regression models.

A total number of 54,386 adult and 60,626 elderly patients (age 65+ years) were included. 60.8% of adult and 62.9% of elderly patients were female. Mean (SD) age was 55 (8) years for deceased and 49.5 (11) years for surviving patients in the adults, and 81.7 (7.6) years for deceased and 77.3 (7.6) years for surviving patients in the elderly sample. Mean (SD) hospital length of stay (HLOS) was 16.7 (18.5) days for deceased and 7.8 (8.1) days for surviving patients in the adults, and 13.7 (13.5) days for deceased and 9.2 (8) days for surviving patients in the elderly sample. Mean (SD) time to operation was 3.7 (4.9) days for deceased and 2.2 (3) days for surviving patients in the adults, and 3.4 (3.8) days for deceased and 2.7 (3) days for surviving patients in the elderly sample. In regression model of adult patients with operation, time to operation (OR=1.07, 95% CI: 1.05-1.09, p<0.001), invasive diagnostic procedure (OR=1.58, 95% CI: 1.17-2.13, p<0.001), and age (OR=1.06, 95% CI 1.05-1.08, p<0.001) were the main risk factors for mortality. Female sex was associated with reduced mortality (OR=0.706, 95% CI 0.64-0.77, p<0.012). In the final multivariable regression model for adult patients with no operation, age (OR=1.09, 95% CI: 1.04-1.15, p<0.001), and HLOS (OR=1.09 95% CI: 1.06-1.12, p<0.001) were the main risk factors for mortality. In the final multivariable regression model for elderly patients with operation, time to operation (OR=1.059, 95% CI 1.046-1.071, p<0.001), and age (OR= 1.077, 95% CI: 1.070-1.084, p<0.001) were the main risk factors for mortality. Female sex was associated with reduced odds of mortality (OR=0.706, 95% CI: 0.643-0.776, p<0.001). In the final multivariable regression the final multivariable model for elderly patients with no operation, HLOS (OR=1.05, 95% CI: 1.03-1.07, p<0.001), and age (OR=1.10, 95% CI: 1.09-1.12, p<0.001) were the main risk factors for mortality. Female sex was associated with reduced odds of mortality (OR=0.70, 95% CI 0.56-0.87, p=0.001).

Delayed operation, extended hospital length of stay, invasive diagnostic procedure, age, and male sex are significant risk factors for in-hospital mortality in emergently admitted patients with intestinal or peritoneal adhesions with obstruction.

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