General Surgery Trainee Cases Over Time: Postgraduate Year Matters

BACKGROUND

Trainees and attending surgeons alike have concerns about resident and fellow operative volume/breadth, competency, and overall readiness for practice. This is an important topic within surgical graduate medical education. Our goal was to analyze the change in general surgery trainee operative experience over time by postgraduate year.

METHODS

Institutional operative records from two corresponding three-month time periods in 2009 and 2018 at the residency program's main hospital site were reviewed. Cases assisted on by general, vascular, or thoracic surgery trainees were included. The number of cases per level, combination of trainees in each case, and categories of cases were compared over time.

RESULTS

There were 1940 cases in 2009 and 1967 cases in 2018 over the respective time periods. The distribution of trainees was different (P < .001), with a similar number of PGY-1 and fellow cases, a decrease in PGY-2 and PGY-5 cases, and an increase in PGY-3 and PGY-4 cases. The number of cases with two trainees, double scrubbed cases, increased from 19.6% to 26.8% (P < .001). In addition, there were differences in the resident years that double scrubbed cases together, an increase in robotic and endovascular surgery, and a decrease in open cases.

CONCLUSIONS

This analysis of cases shows that resident operative volume over approximately a decade has been largely preserved, with some change in the distribution of cases based on trainee level, an increase in cases with more than one trainee, and a rise of minimally invasive surgery with a corresponding decrease in open cases.

Quantifying the Prognostic Value of Preoperative Surgeon Intuition: Comparing Surgeon Intuition and Clinical Risk Prediction as Derived from the American College of Surgeons NSQIP Risk Calculator

BACKGROUND

Surgical risk prediction models traditionally use patient attributes and measures of physiology to generate predictions about postoperative outcomes. However, the surgeon's assessment of the patient may be a valuable predictor, given the surgeon's ability to detect and incorporate factors that existing models cannot capture. We compare the predictive utility of surgeon intuition and a risk calculator derived from the American College of Surgeons (ACS) NSQIP.

STUDY DESIGN

From January 10, 2021 to January 9, 2022, surgeons were surveyed immediately before performing surgery to assess their perception of a patient's risk of developing any postoperative complication. Clinical data were abstracted from ACS NSQIP. Both sources of data were independently used to build models to predict the likelihood of a patient experiencing any 30-day postoperative complication as defined by ACS NSQIP.

RESULTS

Preoperative surgeon assessment was obtained for 216 patients. NSQIP data were available for 9,182 patients who underwent general surgery (January 1, 2017 to January 9, 2022). A binomial regression model trained on clinical data alone had an area under the receiver operating characteristic curve (AUC) of 0.83 (95% CI 0.80 to 0.85) in predicting any complication. A model trained on only preoperative surgeon intuition had an AUC of 0.70 (95% CI 0.63 to 0.78). A model trained on surgeon intuition and a subset of clinical predictors had an AUC of 0.83 (95% CI 0.77 to 0.89).

CONCLUSIONS

Preoperative surgeon intuition alone is an independent predictor of patient outcomes; however, a risk calculator derived from ACS NSQIP is a more robust predictor of postoperative complication. Combining intuition and clinical data did not strengthen prediction.

Association of Patient Belief About Success of Antibiotics for Appendicitis and Outcomes: A Secondary Analysis of the CODA Randomized Clinical Trial

Importance

A patient's belief in the likely success of a treatment may influence outcomes, but this has been understudied in surgical trials.

Objective

To examine the association between patients' baseline beliefs about the likelihood of treatment success with outcomes of antibiotics for appendicitis in the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial.

Design, Setting, and Participants

This was a secondary analysis of the CODA randomized clinical trial. Participants from 25 US medical centers were enrolled between May 3, 2016, and February 5, 2020. Included in the analysis were participants with appendicitis who were randomly assigned to receive antibiotics in the CODA trial. After informed consent but before randomization, participants who were assigned to receive antibiotics responded to a baseline survey including a question about how successful they believed antibiotics could be in treating their appendicitis.

Interventions

Participants were categorized based on baseline survey responses into 1 of 3 belief groups: unsuccessful/unsure, intermediate, and completely successful.

Main Outcomes and Measures

Three outcomes were assigned at 30 days: (1) appendectomy, (2) high decisional regret or dissatisfaction with treatment, and (3) persistent signs and symptoms (abdominal pain, tenderness, fever, or chills). Outcomes were compared across groups using adjusted risk differences (aRDs), with propensity score adjustment for sociodemographic and clinical factors.

Results

Of the 776 study participants who were assigned antibiotic treatment in CODA, a total of 425 (mean [SD] age, 38.5 [13.6] years; 277 male [65%]) completed the baseline belief survey before knowing their treatment assignment. Baseline beliefs were as follows: 22% of participants (92 of 415) had an unsuccessful/unsure response, 51% (212 of 415) had an intermediate response, and 27% (111 of 415) had a completely successful response. Compared with the unsuccessful/unsure group, those who believed antibiotics could be completely successful had a 13-percentage point lower risk of appendectomy (aRD, -13.49; 95% CI, -24.57 to -2.40). The aRD between those with intermediate vs unsuccessful/unsure beliefs was -5.68 (95% CI, -16.57 to 5.20). Compared with the unsuccessful/unsure group, those with intermediate beliefs had a lower risk of persistent signs and symptoms (aRD, -15.72; 95% CI, -29.71 to -1.72), with directionally similar results for the completely successful group (aRD, -15.14; 95% CI, -30.56 to 0.28).

Conclusions and Relevance

Positive patient beliefs about the likely success of antibiotics for appendicitis were associated with a lower risk of appendectomy and with resolution of signs and symptoms by 30 days. Pathways relating beliefs to outcomes and the potential modifiability of beliefs to improve outcomes merit further investigation.

Trial Registration

ClinicalTrials.gov Identifier: NCT02800785.

Pathway-Based Reduction of Repeat Head Computed Tomography for Patients With Complicated Mild Traumatic Brain Injury: Implementation and Outcomes

BACKGROUND

Routine follow-up head imaging in complicated mild traumatic brain injury (cmTBI) patients has not been shown to alter treatment, improve outcomes, or identify patients in need of neurosurgical intervention. We developed a follow-up head computed tomography (CT) triage algorithm for cmTBI patients to decrease the number of routine follow-up head CT scans obtained in this population.

OBJECTIVE

To report our experience with protocol implications and patient outcome.

METHODS

Data on all cmTBI patients presenting from July 1, 2018 to June 31, 2019, to our level 1, tertiary, academic medical center were collected prospectively and analyzed retrospectively. Descriptive analysis was performed.

RESULTS

Of the 178 patients enrolled, 52 (29%) received a follow-up head CT. A total of 27 patients (15%) were scanned because of initial presentation and triaged to the group to receive a routine follow-up head CT. A total of 151 patients (85%) were triaged to the group without routine follow-up head CT scan. Protocol adherence was 89% with 17 violations.

CONCLUSION

Utilizing this protocol, we were able to safely decrease the use of routine follow-up head CT scans in cmTBI patients by 71% without any missed injuries or delayed surgery. Adoption of the protocol was high among all services managing TBI patients.

The Effect of Anticoagulation and Antiplatelet Use in Trauma Patients on Mortality and Length of Stay

BACKGROUND

Though many trauma patients are on anticoagulation or antiplatelet therapy (AAT), there are few generalizable data on the risks for these patients. The purpose of this study was to analyze the impact of anticoagulation (AC) and antiplatelet (AP) therapy on mortality and length of stay (LOS) in general trauma patients.

METHODS

A retrospective review was performed of patients in the institutional trauma registry during 2019 to determine AAT use on admission and discharge. Outcomes were compared using standard statistics.

RESULTS

Of 2261 patients who met the inclusion criteria, 2 were excluded due to an incomplete medication reconciliation, resulting in 2259 patients. Patients on AAT had a higher mortality (4.5% vs 2.1%). On multivariable analysis, preadmission AC (odds ratio OR, 3.325, P = .001), age (OR 1.040, P < .001), and injury severity score ((ISS) 1.094, P < .001) were associated with mortality. Anticoagulation use was also associated with longer LOS on multivariable analysis (OR: 1.626, P = .005). Antiplatelet use was not associated with higher mortality or longer LOS. More patients on AAT were unable to be discharged home. However, patients on AAT did not have a greater blood transfusion requirement or need more hemorrhage control procedures. Lastly, 23.7% of patients on preadmission AAT were not discharged on any AAT.

DISCUSSION

These data demonstrate that patients on AC, but not AP, have greater mortality and longer hospital LOS. This may provide guidance for those being newly started on AAT. Further work to determine which patients benefit most from restarting AAT would lead to improvement in the care of trauma patients.

Effect of midodrine versus placebo on time to vasopressor discontinuation in patients with persistent hypotension in the intensive care unit (MIDAS): an international randomised clinical trial

PURPOSE

ICU discharge is often delayed by a requirement for intravenous vasopressor medications to maintain normotension. We hypothesised that the administration of midodrine, an oral α₁-adrenergic agonist, as adjunct to standard treatment shortens the duration of intravenous vasopressor requirement.

METHODS

In this multicentre, randomised, controlled trial including three tertiary referral hospitals in the US and Australia, we enrolled adult patients with hypotension requiring a single-agent intravenous vasopressor for ≥ 24 h. Subjects received oral midodrine (20 mg) or placebo every 8 h in addition to standard care until cessation of intravenous vasopressors, ICU discharge, or occurrence of adverse events. The primary outcome was time to vasopressor discontinuation. Secondary outcomes included time to ICU discharge readiness, ICU and hospital lengths of stay, and ICU readmission rates.

RESULTS

Between October 2012 and June 2019, 136 participants were randomised, of whom 132 received the allocated intervention and were included in the analysis (modified intention-to-treat approach). Time to vasopressor discontinuation was not different between midodrine and placebo groups (median [IQR], 23.5 [10-54] vs 22.5 [10.4-40] h; difference, 1 h; 95% CI - 10.4 to 12.3 h; p = 0.62). No differences in secondary endpoints were observed. Bradycardia occurred more often after midodrine administration (5 [7.6%] vs 0 [0%], p = 0.02).

CONCLUSION

Midodrine did not accelerate liberation from intravenous vasopressors and was not effective for the treatment of hypotension in critically ill patients.

Gallbladder volvulus in a patient with chronic lymphocytic leukemia treated with laparoscopic cholecystectomy

Gallbladder volvulus is a rare condition that most commonly occurs in elderly women and often mimics acute cholecystitis in its presentation. This condition is a surgical emergency requiring cholecystectomy as it can lead to gallbladder perforation and bilious peritonitis with high morbidity to the patient. An 85-year-old woman with chronic lymphocytic leukemia presented with acute-onset right upper-quadrant abdominal pain and associated nausea with emesis. After admission to the surgical service and initiation of intravenous antibiotics, the patient was taken to the operating room for surgical management due to the persistence of symptoms. Intraoperative findings included a necrotic appearing gallbladder that was twisted on the cystic duct. Laparoscopic cholecystectomy was performed, which was complicated by bile leak requiring endoscopic retrograde cholangiopancreatography with bile duct stenting followed by operative washout. Gallbladder volvulus can be challenging to diagnose. This condition should be suspected in elderly women with acute-onset abdominal pain and imaging concerning for acute cholecystitis. Emergent cholecystectomy is the treatment of choice for gallbladder volvulus.

Acute large bowel pseudo-obstruction due to atrophic visceral myopathy: A case report

PURPOSE

Atrophic visceral myopathy is a pathological diagnosis characterized by atrophy of the smooth muscle layers of the viscera with intact ganglia. Rarely, it can present acutely as an intestinal pseudo-obstruction. We describe a rare case report and explore how this diagnosis can be distinguished from other forms of intestinal obstruction.

CASE DESCRIPTION

A 60-year-old male with a past medical history of hypothyroidism presented to the emergency department with a two-day history of worsening abdominal distention and pain associated with nausea and vomiting. Upon evaluation patient was found to have tachycardia, with abdominal distention and localized tenderness with peritonitis. Computed tomography demonstrated large bowel obstruction, likely caused by sigmoid volvulus. The patient underwent emergent laparotomy. Intra-operatively, the entire colon was found to be extremely dilated and redundant. With a working diagnosis of recurrent sigmoid volvulus causing intermittent large bowel obstruction, a sigmoid colectomy and primary anastomosis was performed. Pathology revealed atrophic visceral myopathy, with an extremely thin colonic wall and atrophic circumferential and longitudinal muscularis propria without inflammation or fibrosis. The ganglion cells and myenteric plexus were unaffected. Post-operatively, the patient developed prolonged ileus requiring nasogastric decompression and parenteral nutrition. The ileus resolved with pro-kinetic agents, and patient was discharged home on post-operative day fifteen.

CONCLUSIONS

Atrophic visceral neuropathy is a rare cause of intestinal pseudo-obstruction. While often presenting with chronic obstruction in younger populations, we present a rare late-onset acute presentation that may have been secondary to underlying hypothyroidism.

Three-dimensional scaffolds of acellular human and porcine lungs for high throughput studies of lung disease and regeneration

Acellular scaffolds from complex whole organs such as lung are being increasingly studied for ex vivo organ generation and for in vitro studies of cell-extracellular matrix interactions. We have established effective methods for efficient de and recellularization of large animal and human lungs including techniques which allow multiple small segments (∼ 1-3 cm(3)) to be excised that retain 3-dimensional lung structure. Coupled with the use of a synthetic pleural coating, cells can be selectively physiologically inoculated via preserved vascular and airway conduits. Inoculated segments can be further sliced for high throughput studies. Further, we demonstrate thermography as a powerful noninvasive technique for monitoring perfusion decellularization and for evaluating preservation of vascular and airway networks following human and porcine lung decellularization. Collectively, these techniques are a significant step forward as they allow high throughput in vitro studies from a single lung or lobe in a more biologically relevant, three-dimensional acellular scaffold.

Differential scanning calorimetry of dispersions of products of oxidation of 1-stearoyl-2-linoleoyl-sn-glycero-3-phosphocholine

Ultraviolet light was used to promote the autoxidation of 1-stearoyl-2-linoleoyl-sn-glycero-3-phosphocholine (SLPC). The extent of oxidation was monitored by ultraviolet spectroscopy, reaction with thiobarbituric acid, fatty acid analysis, and thin-layer chromatography. Fatty acid analysis and thin-layer chromatography appeared to provide the most consistent estimates of oxidation, especially when extensive oxidation had taken place. The oxidized samples were separated by flash chromatography into fractions enriched in different oxidation products. Differential scanning calorimetry of aqueous dispersions of these fractions indicated that oxidation products had higher transition temperatures than the original SLPC.

Interactions between plasma proteins and pulmonary surfactant: pulsating bubble studies

The influence of human albumin, alpha-globulin, and fibrinogen on the actions of porcine pulmonary surfactant in a pulsating bubble surfactometer has been investigated. All three proteins detracted from the ability of the surfactant to adsorb to the air-water interface. The proteins also reduced the ability of surfactant to lower the opening pressures of bubbles cycling between different sizes in suspensions of surfactant. This was equivalent to restricting the ability of the surfactant to achieve low surface tension during compression of the surface. Of the three proteins, globulin competed most effectively with surfactant during the adsorption process, and albumin competed the least effectively. The proteins also may have interfered with the processes of surface refinement, which usually yields a monolayer enriched enough in dipalmitoyl phosphatidylcholine to achieve very low surface tension (very low opening pressures in the bubbles). Of the three proteins tested, albumin was least deleterious to surface refining whereas globulin and fibrinogen appeared to be about equally detrimental to the process.

Interactions between plasma proteins and pulmonary surfactant: surface balance studies

The influence of human fibrinogen, alpha-globulin, and albumin on the properties of monolayers of pulmonary surfactant under dynamic compression and expansion has been studied at 37 degrees C. Each of the proteins altered some of the properties of the normal compression and expansion isotherms of surfactant such that characteristics deemed desirable for proper lung function were impaired. The order of potency of these effects was fibrinogen greater than globulin greater than albumin. The proteins (a) decreased the maximum surface pressure (equivalent to the minimum surface tension) which the surfactant monolayers attained on compression, (b) decreased the areas occupied per mole of lipid phosphorus when the monolayers were at surface tensions of 20 and 12 mN.m-1, (c) reduced the areas of the hysteresis between compression and expansion isotherms, and (d) decreased the rate of change of surface tension with area at the point of initial expansion of the monolayers. The proteins might compete with surfactant lipid for available space at the interface, especially at low film compression. They might also enhance the desorption of lipid from the monolayer. The findings are consistent with the loss of pulmonary function and presence of edema that occur in adult respiratory distress syndrome being contributed to by plasma proteins interfering with surfactant function.

The effect of methylation of phosphatidylethanolamine on the behaviour of lipid monolayers at the air-water interface

Monolayers of DPPE and its N-methylated derivatives including DPPC have been investigated at 23 and 37 degrees C using a modified Langmuir-Wilhelmy surface balance. The monolayers have been subjected to dynamic compression and expansion, and some characteristics of the surfaces have been determined. The minimum surface tension attained by surfaces containing the lipids (maximum surface pressures sustained by the films) depended on the extent of methylation of the head group. Monolayers of DPPE or N-MeDPPE collapsed at surface tensions of 12-16 mN.m-1, whereas those containing N,N-diMeDPPE and DPPC could be compressed to near zero surface tension. The areas per molecule occupied by these lipids under high compression varied slightly and not systematically with head-group methylation. Monolayers containing mixtures of DPPC and DPPE were also studied under the same conditions. The monolayers showed some deviation from the behaviour expected if they were to have characteristics of ideally mixed systems. The minimum surface tensions attained suggested that monolayers containing 50 mol% or more DPPC might be further enriched during compression by some selective exclusion of the DPPE. At high surface pressures, some positive deviations in nominal areas per molecule from that expected for ideal mixing were observed in the monolayers made with 50 mol% or more DPPC. These deviations might be caused by packing disruptions associated with the explosion of lipid from the films.

Serial cultivation of epidermal keratinocytes from psoriatic plaques

Using the combined techniques of Rheinwald and Green, and Liu and Karasek, large quantities of proliferative keratinocytes from involved (PP) or uninvolved (PN) skin of psoriatic patients and from normal skin of non-psoriatic donors (NN) can be obtained. Primary cultures, initiated from a 6-mm punch biopsy, are grown on a 3T3 feeder layer seeded on a collagen surface and fed with Dulbecco's Modified Eagle's Medium containing 20% fetal calf serum, hydrocortisone, epidermal growth factor, and cholera toxin. To test the hypothesis that the mechanism(s) responsible for the abnormal proliferation of psoriatic keratinocytes may be located within the cells themselves, primary cultures are passaged onto collagen surfaces without a feeder layer and maintained with medium plus serum, but no additional supplements, and the growth profiles of the 3 cell populations compared. No difference in morphology among these cells is observed in either primary or passaged cultures. In primary cultures, PP keratinocytes, especially those isolated from active lesions, seem to initiate growth at a slower rate than do PN and NN keratinocytes. The difference in the growth rate, as determined by cell number, DNA content, and mitotic activity, is insignificant among passaged PP, PN, and NN cells. Waves observed in the mitotic index and the metabolic activity of the passaged keratinocytes from all 3 sources suggest that the cells are synchronized during subculturing. The cells have high metabolic and mitotic activities during the first week after subculturing, indicative of an initial population of actively dividing cells. We have not found the characteristic feature of hyperproliferation seen in psoriatic keratinocytes in situ, in the cultured cells; however, it is too early to reach the definite conclusion that the mechanism(s) responsible for psoriasis does not exist in the keratinocyte itself. These 3 cell types may respond differently to agents that either enhance or inhibit cell growth and, by using the culture system outlined in this report, we may study these factors and their potential role in psoriasis.

DNA repair response in human epidermal keratinocytes from donors of different age

We have compared the excision-repair and growth properties of epidermal keratinocytes from humans of different ages. Keratinocytes isolated from newborn and adult abdominal skin at autopsy were cultured on collagen gels. Repair replication was assayed by the 5-bromodeoxyuridine density-labeling method following ultraviolet (UV) irradiation (254 nm) of the cultures. The keratinocytes from newborn donors proliferated more rapidly and attained a higher concentration at confluence than did those from aged donors. Semiconservative DNA replication was inhibited by UV radiation to an equal extent in cell cultures from newborns and adults. After a UV dose of 13 J/m2, the time course of DNA repair was similar for the respective cultures. Furthermore, there were no significant differences in the time course of repair for keratinocytes in the proliferative or the plateau phase of growth. The dose-response curves for repair replication in cells from both young and old donors maximized at about 50 J/m2 but the attenuation in repair at higher doses appeared somewhat greater in cells from older donors. We conclude that no significant age-related differences exist in the rate and extent of the repair-replication response of human epidermal keratinocytes to UV-radiation damage in DNA. However, it remains to be determined whether other cellular recovery responses to damaged DNA are also relatively unrelated to age.

DNA repair responses in human skin cells

Sunlight and some environmental chemical agents produce lesions in the DNA of human skin cells that if unrepaired may interfere with normal functioning of these cells. The most serious outcome of such interactions may be malignancy. It is therefore important to develop an understanding of mechanisms by which the lesions may be repaired or tolerated without deleterious consequences. Our models for the molecular processing of damaged DNA have been derived largely from the study of bacterial systems. Some similarities but significant differences are revealed when human cell responses are tested against these models. It is also of importance to learn DNA repair responses of epidermal keratinocytes for comparison with the more extensive studies that have been carried out with dermal fibroblasts. Our experimental results thus far indicate similarities for the excision-repair of ultraviolet-induced pyrimidine dimers in human keratinocytes and fibroblasts. Both the monoadducts and the interstrand crosslinks produced in DNA by photoactivated 8-methoxypsoralen (PUVA) can be repaired in normal human fibroblasts but not in those from xeroderma pigmentosum patients. The monoadducts, like pyrimidine dimers, are probably the more mutagenic/carcinogenic lesions while the crosslinks are less easily repaired and probably result in more effective blocking of DNA function. It is suggested that a split-dose protocol that maximizes the production of crosslinks while minimizing the yield of monoadducts may be more effective and potentially less carcinogenic than the single ultraviolet exposure regimen in PUVA therapy for psoriasis.