Clinical Update on the Prevention and Management of Postoperative Crohn's Disease Recurrence.

PURPOSE OF REVIEW: Despite advances in therapeutics, a significant portion of patients with Crohn's disease still require surgical management. In this article, we present updates to the natural history, prognostication and postoperative monitoring, and novel therapeutics in the prevention and treatment of postoperative Crohn's disease recurrence. RECENT FINDINGS: Clinical risk factors have been associated with higher rates of postoperative recurrence (POR), and in recent studies demonstrate an increased cumulative risk with presence of additional risk factors. Additional novel clinical, histologic, and "-omic" risk factors for recurrence have recently been elucidated, including the role of the mesentery on recurrence and perioperative intraabdominal septic complications. High-risk patients benefit most from medical prophylaxis, including anti-TNF with or without immunomodulator therapy to prevent recurrence. New biologics such as vedolizumab and ustekinumab have emerging evidence in the use of prophylaxis, especially with recent REPREVIO trial data. Non-invasive disease monitoring, such as cross-sectional enterography, intestinal ultrasound, and fecal calprotectin, have been validated against ileocolonoscopy. Recent advances in the prediction, prevention, and monitoring algorithms of postoperative Crohn's disease may be leading to a reduction in postoperative recurrence. Ongoing trials will help determine optimal monitoring and management strategies for this at-risk population.

Change in Biologic Class Promotes Endoscopic Remission Following Endoscopic Postoperative Crohn's Disease Recurrence.

GOALS: Assess the outcomes of various therapeutic regimens to treat initial endoscopic postoperative recurrence despite biologic prophylaxis. BACKGROUND: Postoperative biologic prophylaxis reduces postoperative Crohn's disease (CD) recurrence rates. Optimal treatment strategies for endoscopic recurrence have not been elucidated. STUDY: Retrospective cohort study of adult CD patients who underwent ileocolonic resection between 2009 and 2020. Patients with endoscopic postoperative recurrence despite prophylactic biologic therapy and ≥1 subsequent colonoscopy were included. Treatment changes after recurrence were categorized as (1) therapy optimization or continuation or (2) new biologic class. The primary outcome was composite endoscopic or surgical recurrence at the time of or prior to subsequent follow-up colonoscopy. RESULTS: Eighty-one CD patients with endoscopic recurrence (54.3% i2b, 22.2% i3, and 23.5% i4) despite biologic prophylaxis (86.4% anti-tumor necrosis factor, 8.6% vedolizumab, 4.9% ustekinumab) were included. Most patients received therapy optimization or continuation (76.3%, n=61) following recurrence compared to being started on a new biologic class. Sixty patients (N=48 therapy optimization; N=12 new biologic class) experienced composite recurrence (78.3% endoscopic, 21.7% surgical). On multivariable modeling, initiation of a new biologic class was associated with reduced risk for composite recurrence compared to therapy optimization or continuation (aOR: 0.26; P=0.04). Additionally, initiation of a new biologic class was associated with endoscopic improvement when adjusting for endoscopic severity at the time of recurrence (aOR: 3.4; P=0.05). On sensitivity analysis, a new biologic class was associated or trended with improved rates of endoscopic healing and composite recurrence when directly compared to therapy optimization or continuation. CONCLUSION: In patients with CD who experience endoscopic recurrence despite biologic prophylaxis, changing the mechanism of biologic action may promote endoscopic improvement.

Anastomotic Configuration and Temporary Diverting Ileostomy Do Not Increase Risk of Anastomotic Stricture in Postoperative Crohn's Disease.

INTRODUCTION: Surgical management of Crohn's disease (CD) is common. Postoperative complications include anastomotic stricturing (AS). The natural history and risk factors for AS have not been elucidated. METHODS: A retrospective cohort study of patients with CD who underwent ileocolonic resection (ICR) with ≥1 postoperative ileocolonoscopy between 2009 and 2020. Postoperative ileocolonoscopies with corresponding cross-sectional imaging were evaluated for evidence of AS without neoterminal ileal extension. Severity of AS and endoscopic intervention at time of detection were collected. Primary outcome was development of AS. Secondary outcome was time to AS detection. RESULTS: A total of 602 adult patients with CD underwent ICR with postoperative ileocolonoscopy. Of these, 426 had primary anastomosis, and 136 had temporary diversion at time of ICR. Anastomotic configuration consisted of 308 side-to-side, 148 end-to-side, and 136 end-to-end. One hundred ten (18.3%) patients developed AS with median time of 3.2 years to AS detection. AS severity at time of detection was associated with need for repeat surgical resection for AS. On multivariable Cox proportional hazard regression, anastomotic configuration and temporary diversion were not associated with risk of or time to AS. Preoperative stricturing disease was associated with decreased time to AS (adjusted hazard ratio 1.8; P = 0.049). Endoscopic ileal recurrence before AS was not associated with subsequent AS detection. DISCUSSION: AS is a relatively common postoperative CD complication. Patients with previous stricturing disease behavior are at increased risk of AS. Anastomotic configuration, temporary diversion, and ileal CD recurrence do not increase risk of AS. Early detection and intervention for AS may help prevent progression to repeat ICR.

The impact of the COVID-19 pandemic on Clostridioides difficile infection and utilization of fecal microbiota transplantation.

Previous research has demonstrated that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) gains cell entry through the angiotensin-converting enzyme 2 receptor, which is abundantly found throughout the gastrointestinal (GI) tract, resulting in a wide array of GI manifestations of coronavirus disease 2019 (COVID-19). By gaining entry into the intestinal epithelial and stromal cells, SARS-CoV-2 has been observed to cause intestinal inflammation and gut dysbiosis. Alterations in gut microbiota are known to be involved in the pathophysiology of Clostridioides difficile infection (CDI). During the initial stages of the COVID-19 pandemic, rates of CDI were similar to historical data despite the increased use of antibiotics. This may be due to increased emphasis on hygiene and protective equipment and reduced C. difficile testing as diarrhea was presumed to be COVID-19 related. Studies also demonstrated additional risk factors for CDI in COVID-19 patients, including length of hospitalization and new abdominal pain during admission. Although not associated with increased mortality, CDI was associated with increased length of hospital stay among patients admitted with COVID-19. Due to fecal viral shedding and concern of oral-fecal transmission of SARS-CoV-2, increased safety regulations were introduced to fecal microbiota transplantation (FMT) leading to reduced rates of this procedure during the COVID-19 pandemic. FMT for recurrent CDI during the COVID-19 pandemic remained highly effective without any reports of SARS-CoV-2 transmission. In addition, limited data show that FMT may be effective in treating COVID-19 and restoring healthy gut microbiota. The goal of this article is to review the impact that the COVID-19 pandemic has had on hospital-acquired CDI and the utilization of FMT.

Early Initiation of Antitumor Necrosis Factor Therapy Reduces Postoperative Recurrence of Crohn's Disease Following Ileocecal Resection.

BACKGROUND: Postoperative recurrence (POR) of Crohn's disease (CD) is common after surgical resection. We aimed to compare biologic type and timing for preventing POR in adult CD patients after ileocecal resection (ICR). METHODS: We performed a retrospective cohort study of CD patients who underwent an ICR at 2 medical centers. Recurrence was defined by endoscopy (≥ i2b Rutgeerts score) or radiography (active inflammation in neoterminal ileum) and stratified by type and timing of postoperative prophylactic biologic within 12 weeks following an ICR (none, tumor necrosis factor antagonists [anti-TNF], vedolizumab, and ustekinumab). RESULTS: We identified 1037 patients with CD who underwent an ICR. Of 278 (26%) who received postoperative prophylaxis, 80% were placed on an anti-TNF agent (n = 223) followed by ustekinumab (n = 28, 10%) and vedolizumab (n = 27, 10%). Prophylaxis was initiated in 35% within 4 weeks following an ICR and in 65% within 4 to 12 weeks. After adjusting for factors associated with POR, compared with no biologic prophylaxis, the initiation of an anti-TNF agent within 4 weeks following an ICR was associated with a reduction in POR (adjusted hazard ratio, 0.61; 95% CI, 0.40-0.93). Prophylaxis after 4 weeks following an ICR or with vedolizumab or ustekinumab was not associated with a reduction in POR compared with those who did not receive prophylaxis. CONCLUSION: Early initiation of an anti-TNF agent within 4 weeks following an ICR was associated with a reduction in POR. Vedolizumab or ustekinumab, at any time following surgery, was not associated with a reduction in POR, although sample size was limited.

Postoperative recurrence of Crohn's disease is common after ileocecal resection. In this dual-center study, early initiation of an anti-TNF agent within 4 weeks following an ileocecal resection was associated with a reduction in postoperative recurrence of Crohn's disease.

Intra-abdominal septic complications after ileocolic resection increases risk for endoscopic and surgical postoperative Crohn's disease recurrence.

BACKGROUND: Postoperative recurrence [POR] of Crohn's disease following ileocolonic resection is common. The impact of immediate postoperative intra-abdominal septic complications [IASC] on endoscopic and surgical recurrence has not been elucidated. AIMS: To evaluate if IASC is associated with an increased risk for endoscopic and surgical POR. METHODS: This was a retrospective study of adult Crohn's disease patients undergoing ileocolonic resection with primary anastomosis between 2009 and 2020. IASC was defined as anastomotic leak or intra-abdominal abscess within 90 days of the date of surgery. Multivariable logistic and Cox proportional hazard modelling were performed to assess the impact of IASC on endoscopic POR [modified Rutgeerts' score ≥ i2b] at index postoperative ileocolonoscopy and long-term surgical recurrence. RESULTS: In 535 Crohn's disease patients [median age 35 years, 22.1% active smokers, 35.7% one or more prior resection] had an ileocolonic resection with primary anastomosis. A minority of patients [N = 47; 8.8%] developed postoperative IASC. In total, 422 [78.9%] patients had one or more postoperative ileocolonoscopies, of whom 163 [38.6%] developed endoscopic POR. After adjusting for other risk factors for postoperative recurrence, postoperative IASC was associated with significantly greater odds (adjusted odds ratio [aOR]: 2.45 [1.23-4.97]; p = 0.01) and decreased time (adjusted hazards ratio [aHR]: 1.60 [1.04-2.45]; p = 0.03] to endoscopic POR. Furthermore, IASC was associated with increased risk (aOR: 2.3 [1.04-4.87] p = 0.03) and decreased survival-free time [aHR: 2.53 [1.31-4.87]; p = 0.006] for surgical recurrence. CONCLUSION: IASC is associated with an increased risk for endoscopic and surgical POR of Crohn's disease. Preoperative optimization to prevent IASC, in addition to postoperative biological prophylaxis, may help reduce the risk for endoscopic and surgical POR.

Mild neoterminal ileal post-operative recurrence of Crohn's disease conveys higher risk for severe endoscopic disease progression than isolated anastomotic lesions.

There are conflicting data assessing the impact of isolated post-operative anastomotic inflammation on future disease progression. The aim of this study was to determine the relative risk of severe disease progression in post-operative Crohn's disease (CD) patients with isolated anastomotic disease. METHODS: Retrospective cohort study of adult CD patients undergoing ileocolonic resection between 2009 and 2020. Patients with a post-operative ileocolonoscopy ≤18 months from surgery and ≥1 subsequent ileocolonoscopy were included. Disease activity was assessed using the modified Rutgeerts' score (RS). Primary outcome was severe endoscopic progression, defined as i3 or i4 disease, on immediate subsequent ileocolonoscopy and during entire post-operative follow-up. Secondary outcome was surgical recurrence. RESULTS: One hundred and ninety-nine CD patients had an ileocolonoscopy ≤18 months from surgery, index RS of i0-i2b and ≥1 subsequent ileocolonoscopy. At index ileocolonoscopy, 34.7% had i0 disease, 16.1% i1, 24.6% i2a and 24.6% i2b. On multivariable logistic regression, i2b disease was associated with severe endoscopic progression compared to i0 or i1 (aOR 5.53; P < 0.001) and i2a disease patients (aOR 2.63; P = 0.03). However, i2a disease did not confer increased risk compared to i0 or i1 disease (P = 0.09). Furthermore, i2b patients experienced severe endoscopic progression significantly earlier than i0 or i1 disease (aHR 4.68; P < 0.001), whereas i2a disease did not differ from i0 or i1 disease (P = 0.25). Surgical recurrence was not associated with index RS i0-i2b (P = 0.86). CONCLUSION: Post-operative ileal disease recurrence, not isolated anastomotic inflammation, confers increased risk for severe endoscopic disease progression. Location of CD recurrence may impact optimal management strategies.

Test Characteristics of Cross-sectional Imaging and Concordance With Endoscopy in Postoperative Crohn's Disease.

BACKGROUND & AIMS: Postoperative Crohn's disease (CD) surveillance relies on endoscopic monitoring. The role of cross-sectional imaging is less clear. We evaluated the concordance of cross-sectional enterography with endoscopic recurrence and the predictive ability of radiography for future CD postoperative recurrence. METHODS: We performed a multi-institution retrospective cohort study of postoperative adult patients with CD who underwent ileocolonoscopy and cross-sectional enterography within 90 days of each other following ileocecal resection. Imaging studies were interpreted by blinded, expert CD radiologists. Patients were categorized by presence of endoscopic postoperative recurrence (E+) (modified Rutgeerts' score ≥i2b) or radiographic disease activity (R+) and grouped by concordance status. RESULTS: A total of 216 patients with CD with paired ileocolonoscopy and imaging were included. A majority (54.2%) exhibited concordance (34.7% E+/R+; 19.4% E-/R-) between studies. The plurality (41.7%; n = 90) were E-/R+ discordant. Imaging was highly sensitive (89.3%), with low specificity (31.8%), in detecting endoscopic postoperative recurrence. Intestinal wall thickening, luminal narrowing, mural hyper-enhancement, and length of disease on imaging were associated with endoscopic recurrence (all P < .01). Radiographic disease severity was associated with increasing Rutgeerts' score (P < .001). E-/R+ patients experienced more rapid subsequent endoscopic recurrence (hazard ratio, 4.16; P = .033) and increased rates of subsequent endoscopic (43.8% vs 22.7%) and surgical recurrence (20% vs 9.5%) than E-/R- patients (median follow-up, 4.5 years). CONCLUSIONS: Cross-sectional imaging is highly sensitive, but poorly specific, in detecting endoscopic disease activity and postoperative recurrence. Advanced radiographic disease correlates with endoscopic severity. Patients with radiographic activity in the absence of endoscopic recurrence may be at increased risk for future recurrence, and closer monitoring should be considered.

Dimensions and Morphologic Variability of the Retro-Orbicularis Oculi and Frontalis Muscle Fat Pad.

PURPOSE: To quantify the complete dimensions of the retro-orbicularis oculi fat (ROOF) pad and to determine its relationship to other fat compartments of the forehead. METHODS: The entire forehead of 14 hemifaces of seven fresh frozen human cadavers (four female, three male) was dissected in the subcutaneous and submuscular planes. For each plane, a ruler was placed at the facial midline, and images of the dissection plane were taken at 90° and 45°. Images were analyzed for vertical height, horizontal length, the distance to midline from the point of maximal height, and area for each hemiface of the ROOF and for the entire fat compartment contiguous with the ROOF. A two-tailed t test was conducted between ROOF and ROOF plus the extended fat plane across all measurements. A Wilcoxon nonparametric signed rank test was performed to determine equivalent fat distribution of the extended fat plane over each cadaver's respective eye. RESULTS: The deep fat originating from the ROOF consistently extended laterally and superiorly in each specimen, distinctly separated via septae from the deep central, deep lateral, and the deep temporal fat compartments. The color, composition, and distribution of this contiguous deep fat did not differ phenotypically from the traditional ROOF. The extended deep fat plane possessed an average vertical height of 3.09 ± 0.68 cm, average distance to midline from point of maximal height of 3.56 ± 0.53 cm, an average horizontal length of 5.37 ± 0.82 cm, and an average area of 13.40 ± 2.69 cm. The extended deep fat demonstrated a statistically significant increase in maximal height, length, and total area compared with the ROOF. A Wilcoxon nonparametric signed rank test was nonsignificant (α = 0.01) across all measurements, demonstrating that the extended fat plane was similarly distributed over each eye. CONCLUSIONS: A layer of deep fat originating from the traditionally defined ROOF extends superiorly and laterally beneath the frontalis muscle, separate from the deep lateral, deep central, and deep temporal fat pads. This is the first study to clearly demonstrate a contiguous superficial musculoaponeurotic system layer of fat extending under both the orbicularis oculi and frontalis muscles. This plane of fat is more appropriately described as the retro-orbicularis oculi and frontalis fat.

Comparisons between Garcia, Modo, and Longa rodent stroke scales: Optimizing resource allocation in rat models of focal middle cerebral artery occlusion.

The use of rodent stroke models allow for the understanding of stroke pathophysiology. There is currently no gold standard neurological assessment to measure deficits and recovery from stroke in rodent models. Agreement on a universal preclinical stroke scale allows for comparison of the outcomes among conducted studies. The present study aimed to compare three routinely used neurological assessments in rodent studies (i.e., Garcia, Modo, and Longa) to determine which is most effective for accurately and consistently quantifying neurological deficits in the context of focal middle cerebral artery occlusion (MCAo) in rats. Focal MCAo was induced in 22 male Wistar rats using a novel transfemoral approach. Rodents were assessed for neurological deficit pre-injury as well as 3 and 24h post-injury. Data was analyzed to determine Pearson correlation coefficients in addition to McNemar's χ(2) values between each pair of neurological assessments. All three stroke scales, Garcia, Modo, and Longa, showed statistically significant changes between the baseline and the 3-hour neurological assessments. A trend towards neurological recovery was observed in all three stroke scales between the 3 and 24-hour endpoints. The three scales were highly correlated with each other, with Garcia and Modo having the strongest correlation. Of the three pairwise analyses, the comparison between the Garcia and Longa tests demonstrated the highest McNemar's χ(2) value, indicating least marginal homogeneity between these two tests. The combination of high correlation between Garcia and Modo tests along with greatest marginal heterogeneity observed between the Garcia and Longa test lead us to recommend the use of Garcia and Longa neurological scales when researchers are hoping to capture the broadest range of neurological factors using only two stroke scales.

Application of Tauroursodeoxycholic Acid for Treatment of Neurological and Non-neurological Diseases: Is There a Potential for Treating Traumatic Brain Injury?

The objective of this review was to evaluate the potential of tauroursodeoxycholic acid (TUDCA) for neuroprotection in traumatic brain injury (TBI) patients in the neurocritical care setting. Specifically, we surveyed preclinical studies describing the neuroprotective and systemic effects of TUDCA, and the potential therapeutic application of TUDCA. Preclinical studies have provided promising data supporting its use in neurological disease characterized by apoptosis-induced neuronal loss. TUDCA inhibits multiple proteins involved in apoptosis and upregulates cell survival pathways. In addition, TUDCA exhibits anti-inflammatory effects in models of neuroinflammation and attenuates neuronal loss in chronic neurodegenerative diseases. This may be applicable to TBI, which also triggers inflammatory and apoptotic processes. Additionally, preliminary data support the use of pharmacological therapies that reduce apoptosis and inflammation associated with TBI. The anti-apoptotic and anti-inflammatory mechanisms of TUDCA could prove promising in the treatment of TBI. Currently, there are no published data supporting improvement in clinical outcomes of TBI by treatment with TUDCA, but future studies should be considered.

A modified beam-walking apparatus for assessment of anxiety in a rodent model of blast traumatic brain injury.

The elevated plus maze (EPM) is used to assess anxiety in rodents. Beam-walking tasks are used to assess vestibulomotor function. Brain injury in rodents can disrupt performance on both of these tasks. Developing novel paradigms that integrate tasks like these can reduce the need for multiple tests when attempting to assess multiple behaviors in the same animal. Using adult male rats, we evaluated the use of a modified beam-walking (MBW) apparatus as a surrogate indicator for anxiety. We used a model of blast-induced traumatic brain injury (bTBI). A total of 39 rats were assessed before and at 3, 6, 24, 72, and 168h either post- bTBI (n=33) or no-injury (n=6) using both EPM and MBW. A novel anxiety index was calculated that encompassed peeks and re-emergences on MBW. The proposed MBW anxiety index was compared with the standard anxiety index calculated from exploration into different sections of EPM. Post- bTBI, rats had an increased anxiety index when measured using EPM. Similarly, they peeked or fully emerged less out of the safe box on MBW. It was found that this novel MBW anxiety index captured similar aspects of behavior when compared to the standard anxiety index obtained from EPM. Further, these effects were dissociated from the effects of bTBI on motor function simultaneously measured on MBW. Over the course of 168h post-bTBI, rats gradually recovered on both EPM and MBW. The MBW apparatus succeeded at capturing and dissociating two separate facets of rat behavior, motor function and anxiety, simultaneously.

Vagus Nerve Stimulation and Other Neuromodulation Methods for Treatment of Traumatic Brain Injury.

The objective of this paper is to review the current literature regarding the use of vagus nerve stimulation (VNS) in preclinical models of traumatic brain injury (TBI) as well as discuss the potential role of VNS along with alternative neuromodulation approaches in the treatment of human TBI. Data from previous studies have demonstrated VNS-mediated improvement following TBI in animal models. In these cases, VNS was observed to enhance motor and cognitive recovery, attenuate cerebral edema and inflammation, reduce blood brain barrier breakdown, and confer neuroprotective effects. Yet, the underlying mechanisms by which VNS enhances recovery following TBI remain to be fully elucidated. Several hypotheses have been offered including: a noradrenergic mechanism, reduction in post-TBI seizures and hyper-excitability, anti-inflammatory effects, attenuation of blood-brain barrier breakdown, and cerebral edema. We present other potential mechanisms by which VNS acts including enhancement of synaptic plasticity and recruitment of endogenous neural stem cells, stabilization of intracranial pressure, and interaction with the ghrelin system. In addition, alternative methods for the treatment of TBI including deep brain stimulation, transcranial magnetic stimulation, transcranial direct current stimulation, and focused ultrasound stimulation are discussed. Although the primary source data show that VNS improves TBI outcomes, it remains to be determined if these findings can be translated to clinical settings.