Postoperative complications and their association with post-traumatic stress disorder in academic vascular surgeons.

OBJECTIVES: Postoperative complications are an inherent component of surgical practice. This study seeks to address their association with emotional responses of academic vascular surgeons. METHODS: An anonymous electronic survey was sent to all vascular surgery program directors in North America with a request to disseminate to their faculty. The survey captured data on demographics and practice type and used imbedded validated measures to determine emotional responses to postoperative complications and to assess coping mechanisms. Univariate analysis was performed to determine differences between those who reported at least partial symptoms of post-traumatic stress disorder (PTSD) following their worse major complication over the previous year and those who did not. Multivariable logistic regression analysis was performed for all covariates found significant on univariate analysis, and those deemed clinically relevant. RESULTS: The survey was distributed to 267 faculty at 128 institutions in the United States and 10 institutions in Canada and completed by 65 participants (response rate, 32%). Twenty of 65 (31%) identified as female, and the total group had a mean age of 47 ± 10.2 years. Most respondents (43/65; 66%) reported a major complication within 3 months of the survey, with the majority of respondents (45/65; 69%) reporting the outcome of patient mortality. Of respondents, 20 of 65 (31%) demonstrated at least partial symptoms of PTSD in response to the worst complication from the previous year, with 12 of 65 (19%) meeting the clinical diagnosis of PTSD. Respondents in the PTSD group were more likely to criticize/blame themselves following the complication (P = .0028); less likely to identify the complication as "expected" (P = .048) or to believe causes of their complications were due to others/external factors; and more likely to identify as a female (55% vs 20%; P = .008). Regarding support following major complications, most respondents (57/65; 88%) desired the ability to discuss details of the case with a respected peer. The most common external pressure influencing their emotional responses to complications was maintaining reputation and a sense of honor (66%). Gender differences persisted on multivariate analysis (P = .016). CONCLUSIONS: Emotional responses following major postoperative complications in vascular surgery are common and may pose a risk for PTSD. This may occur more commonly following complications that are unexpected or in cases in which the cause of the complication was due to a perceived or actual surgical mistake. The ubiquitous nature and severity of the emotional toll of major complications for vascular surgeons is poorly described and under-recognized. Gender-related differences may exist, and most surgeons desire a support network of respected peers with whom to discuss complications.

A non-canonical retina-ipRGCs-SCN-PVT visual pathway for mediating contagious itch behavior.

Contagious itch behavior informs conspecifics of adverse environment and is crucial for the survival of social animals. Gastrin-releasing peptide (GRP) and its receptor (GRPR) in the suprachiasmatic nucleus (SCN) of the hypothalamus mediates contagious itch behavior in mice. Here, we show that intrinsically photosensitive retina ganglion cells (ipRGCs) convey visual itch information, independently of melanopsin, from the retina to GRP neurons via PACAP-PAC1R signaling. Moreover, GRPR neurons relay itch information to the paraventricular nucleus of the thalamus (PVT). Surprisingly, neither the visual cortex nor superior colliculus is involved in contagious itch. In vivo calcium imaging and extracellular recordings reveal contagious itch-specific neural dynamics of GRPR neurons. Thus, we propose that the retina-ipRGC-SCN-PVT pathway constitutes a previously unknown visual pathway that probably evolved for motion vision that encodes salient environmental cues and enables animals to imitate behaviors of conspecifics as an anticipatory mechanism to cope with adverse conditions.

Lower systemic inflammation is associated with gut firmicutes dominance and reduced liver injury in a novel ambulatory model of parenteral nutrition.

BACKGROUND: Total Parenteral Nutrition (TPN) provides lifesaving nutritional support to patients unable to maintain regular enteral nutrition (EN). Unfortunately, cholestasis is a significant side effect affecting 20-40% of paediatric patients. While the aetiology of TPN-associated injury remains ill-defined, an altered enterohepatic circulation in the absence of gut luminal nutrient content during TPN results in major gut microbial clonal shifts, resulting in metabolic endotoxemia and systemic inflammation driving liver injury and cholestasis. HYPOTHESIS: To interrogate the role of gut microbiota, using our novel ambulatory TPN piglet model, we hypothesized that clonal reduction of bacteria in Firmicutes phylum (predominant in EN) and an increase in pathogenic Gram-negative bacteria during TPN correlates with an increase in serum lipopolysaccharide and systemic inflammatory cytokines, driving liver injury. METHODS: Upon institutional approval, 16 animals were allocated to receive either TPN (n = 7) or EN only (n = 9). The TPN group was subdivided into a low systemic inflammation (TPN-LSI) and high systemic inflammation (TPN-HSI) based on the level of serum lipopolysaccharide. Culture-independent identification of faecal bacterial populations was determined by 16S rRNA. RESULTS: Piglets on TPN, in the TPN-HSI group, noted a loss of enterocyte protective Firmicutes bacteria and clonal proliferation of potent inflammatory and lipopolysaccharide containing pathogens: Fusobacterium, Bacteroidetes and Campylobacter compared to EN animals. Within the TPN group, the proportion of Firmicutes phylum correlated with lower portal lipopolysaccharide levels (r = -0.89). The TPN-LSI had a significantly lower level of serum bile acids compared to the TPN-HSI group (7.3 vs. 60.4 mg/dL; p = .018), increased day 14 weight (5.67 vs. 5.07 kg; p = .017) as well as a 13.7-fold decrease in serum conjugated bilirubin. CONCLUSION: We demonstrate a novel relationship between the gut microbiota and systemic inflammation in a TPN animal model. Pertinently, the degree of gut dysbiosis correlated with the severity of systemic inflammation. This study underscores the role of gut microbiota in driving liver injury mechanisms during TPN and supports a paradigm change in therapeutic targeting of the gut microbiota to mitigate TPN-related injury. KEY MESSAGESThis study identified a differential link between gut microbiota and inflammation-the higher the dysbiosis, the worse the systemic inflammatory markers.Higher levels of Firmicutes species correlated with reduced inflammation.

Malpractice litigation in elective lumbar spinal fusion: a comprehensive review of reported legal claims in the U.S. in the past 50 years.

BACKGROUND CONTEXT: In the U.S., medical malpractice litigation is associated with significant financial costs and often leads to the practice of defensive medicine. Among medical subspecialities, spine surgery is disproportionately impacted by malpractice claims. PURPOSE: To provide a comprehensive assessment of reported malpractice litigation claims involving elective lumbar spinal fusion (LSF) surgery during the modern era of spine surgery instrumentation in the U.S., to identify factors associated with verdict outcomes, and to compare malpractice claims characteristics between different approaches for LSF. STUDY DESIGN/SETTING: A retrospective review. PATIENT SAMPLE: Patients undergoing elective lumbar spinal fusion surgery. OUTCOME MEASURES: The primary outcome measure was verdict outcome (defendant vs. plaintiff verdict). Secondary outcome measures included alleged malpractice, injury/damage claimed, and award payouts. METHODS: The Westlaw legal database (Thomson Reuters, New York, NY, USA) was queried for verdict and settlement reports pertaining to elective LSF cases from 1970 to 2021. Data were collected regarding patient demographics, surgeon specialty, fellowship training, state/region, procedure, institutional setting (academic vs. community hospital), alleged malpractice, injury sustained, case outcomes, and monetary award. RESULTS: A total of 310 cases were identified, yielding 67% (n=181) defendant and 24% (n=65) plaintiff verdicts, with 9% (n=26) settlements. Neurosurgeons and orthopedic spine surgeons were equally named as the defendant (45% vs. 51% respectively, p=0.59). When adjusted for inflation, the median final award for plaintiff verdicts was $1,241,286 (95% CI: $884,850-$2,311,706) while the median settlement award was $925,000 (95% CI: $574,800-$1,787,130), with no stastistically significant differences between verdict and reported settlement payouts (p=0.49). The Northeast region displayed significantly higher award payouts compared to other U.S. regions (p=0.02). There were no associations in awards outcomes when comparing alleged malpractice, alleged injuries/damages, institutional setting, surgical procedures, and surgeon specialty or fellowship training. The most common claims were intraoperative error (28%, n=107) followed by failure to obtain informed consent (24%, n=94). In the analyzed cohort, the most common injuries leading to litigation were refractory pain and suffering (37%, n=149) followed by permanent neurological deficits (26%, n=106). There were no differences in alleged malpractice or injury sustained between cases in which the outcome was favorable to defendant versus plaintiff. Anterior lumbar interbody fusion (ALIF) cases were 2.75 times more likely to be cited for excessive or inappropriate surgery (OR: 2.75 [95% CI: 1.14, 6.86], p=0.02) when compared to posterior surgical approaches. CONCLUSION: The results of our analysis of reported claims suggest that medical malpractice litigation involving elective LSF is associated with jury verdicts over $1 million per case, with the most common alleged malpractice being intraoperative error and failure to obtain informed consent. Surgeon specialty, fellowship training, procedure type, and institution type were not associated with greater litigation risks; however, ALIF surgery had a significantly higher risk of involving claims of excessive or inappropriate surgery compared to posterior approaches for lumbar fusion. In addition, claims were significantly higher in the Northeast compared to other U.S. regions. Efforts to improve patient education through shared-decision making and proactive strategies to avoid, detect, and mitigate intra-operative procedural errors may decrease the risk of litigation in elective LSF.

Carbamazepine mitigates parenteral nutrition-associated liver disease in a novel ambulatory piglet model.

BACKGROUND: Parenteral nutrition (PN) remains a critical therapeutic option in patients who cannot tolerate enteral feeding. However, although lifesaving, PN is associated with significant side effects, including liver injury, the etiology of which is multifactorial. Carbamazepine (CBZ), an antiepileptic medication, is known to modulate hepatic fibrosis and hepatocellular injury in a variety of liver diseases. We hypothesized that CBZ could prevent PN-associated liver disease (PNALD), which we tested by using our novel ambulatory PN piglet model. METHODS: Piglets were fitted with jugular catheters and infusion pumps for PN and randomized to enteral nutrition (n = 7), PN (n = 6), or PN with parenteral CBZ (n = 6) for 2 weeks. Serum and liver tissue were analyzed via light microscopy, quantification of serum liver injury markers, Ki67 and cytokeratin-7 indexing, and real-time quantitative polymerase chain reaction. RESULTS: PN-fed piglets in our model developed manifestations of PNALD-particularly, increased serum bilirubin, gamma-glutamyltransferase, liver cholestasis, and Ki67 expression compared with that of EN-fed animals (P < 0.03). CBZ therapy in PN-fed animals led to a significant reduction in these markers of injury (P < 0.05). Investigation into the mechanism of these therapeutic effects revealed increased expression of sterol regulatory element-binding protein 1 (SREBP-1), peroxisome proliferator-activated receptor alpha (PPAR-α), and fatty acid binding protein (FABP) in PN-fed animals receiving CBZ (P < 0.03). Further investigation revealed increased LC3 expression and decreased lysosomal-associated membrane protein (LAMP1) expression with CBZ (P < 0.03). CONCLUSION: CBZ administration mitigates PNALD severity, suggesting a novel therapeutic strategy targeting PN-associated side effects, and may present a paradigm change to current treatment options.

Novel NMP split liver model recapitulates human IRI and demonstrates ferroptosis modulators as a new therapeutic strategy.

BACKGROUND: Almost 9%of deceased donor livers are discarded as marginal donor livers (MDL) due to concern of severe ischemia reperfusion injury (IRI). Emerging data supports ferroptosis (iron regulated hepatocellular death) as an IRI driver, however lack of robust preclinical model limits therapeutic testing. In this manuscript we describe the development of a novel rigorous internal control system utilizing normothermic perfusion of split livers to test ferroptosis regulators modulating IRI. METHODS: Upon institutional approval, split human MDLs were placed on our normothermic perfusion machine, Perfusion Regulated Organ Therapeutics with Enhanced Controlled Testing (PROTECT), pumping arterial and portal blood. Experiment 1 compared right (UR) and left (UL) lobes to validate PROTECT. Experiment 2 assessed ferroptosis regulator Deferoxamine in Deferoxamine Agent Treated (DMAT) vs. No Agent Internal Control (NAIC) lobes. Liver serology, histology, and ferroptosis genes were assessed. RESULTS: Successful MDL perfusion validated PROTECT with no ALT or AST difference between UR and UL (∆ALT UR: 235, ∆ALT UL: 212; ∆AST UR: 576, ∆AST UL: 389). Liver injury markers increased in NAIC vs. DMAT (∆ALT NAIC: 586, ∆ALT DMAT: -405; ∆AST NAIC: 617, ∆AST DMAT: -380). UR and UL had similar expression of ferroptosis regulators RPL8,HO-1 and HIFα. Significantly decreased intrahepatic iron (p = .038), HO-1 and HIFα in DMAT (HO-1 NAIC: 6.93, HO-1 DMAT: 2.74; HIFαNAIC: 8.67, HIFαDMAT: 2.60)and no hepatocellular necrosis or immunohistochemical staining (Ki67/Cytokeratin-7) differences were noted. CONCLUSION: PROTECT demonstrates the therapeutic utility of a novel normothermic perfusion split liver system for drug discovery and rapid translatability of therapeutics, driving a paradigm change in organ recovery and transplant medicine. Our study using human livers, provides preliminary proof of concept for the novel role of ferroptosis regulators in driving IRI.

Parenteral Nutrition and Cardiotoxicity.

Parenteral nutrition (PN) is a life-saving nutritional therapy for those situations when patients are unable to receive enteral nutrition. However, despite a multitude of benefits offered by PN, it is associated with a variety of side effects, most notably parenteral nutrition-associated liver disease (PNALD). Adverse effects of PN on other organ systems, such as brain and cardiovascular system, have been poorly studied. There have been several case reports, studies, and a recent animal study highlighting cardiotoxic effects of PN; however, much remains unclear about the underlying mechanisms causing cardiac damage. In this review, we propose a series of potential mechanisms behind PN-associated heart injury, and we provide an overview of therapeutic strategies and recent scientific advances.

Advances in the Epidemiology, Diagnosis, and Management of Pediatric Fatty Liver Disease.

PURPOSE: Nonalcoholic fatty liver (NAFL) is a major contributor to pediatric liver disease. This review evaluated the current literature on prevalence, screening, diagnosis, and management of NAFL in children and explored recent advances in the field of pediatric NAFL. METHODS: A PubMed search was performed for manuscripts describing disease burden, diagnosis, and management strategies in pediatric NAFL published within the past 15 years. Systematic reviews, clinical practice guidelines, randomized controlled trials, and cohort and case-control studies were reviewed for the purpose of this article. FINDINGS: The prevalence of NAFL in children is increasing. It is a leading cause of liver-related morbidity and mortality in children. Screening and diagnosis of NAFL in children are a challenge. Lifestyle changes and exercise are the cornerstones of the management of NAFL. IMPLICATIONS: Further research is needed to develop better screening and diagnostic tools for pediatric NAFL, including noninvasive diagnostics. NAFL therapeutics is another area of much-needed, ongoing research.

Role of Bile Acids and Gut Microbiota in Parenteral Nutrition Associated Injury.

Total Parenteral Nutrition (TPN) is a life-saving therapy where all nutritional requirements are provided intravenously. While this therapy is essential for individuals unable to process their nutritional needs enterically, significant complications arise such as intestinal failure associated liver injury (IFALD). IFALD includes hepatic steatosis, cholestasis, inflammation, ultimately progressing to cirrhosis and portal hypertension and some patients may need liver transplantation. The exact mechanism underlying this condition is not well understood, but studies have recently suggested that changes in gut microbiota and intraluminal bile acid signaling are known to play a role in the development of IFALD. In enterohepatic circulation with normal enteral nutrition, gut Farnesoid X Receptor (FXR) is activated by bile acids, which triggers the release of Fibroblast Growth Factor 19 (FGF19) into portal circulation. FGF19 serves to regulate intrahepatic bile acid synthesis with enteric nutrition. This signaling pathway is impaired in TPN as studies indicate decreased serum levels of FGF19 in subjects receiving TPN. Finally, gut microbiota is severely altered in TPN due to intestinal hypomobility. The shift in gut microbiota affects our immune response and promotes endotoxins that negatively affect liver function. Targeting the pathways affecting gut microbiota and bile acid signaling has promise in treating TPN associated injuries.