Association of Nicotine Cessation Time on the Incidence of Recurrent Incisional Hernia Repair and Postoperative Surgical Site Occurrences

BACKGROUND

Nicotine products are believed to be associated with a higher incidence of incisional hernia (IH) recurrence and postoperative complications after IH repair.

METHODS

A retrospective analysis of the Abdominal Core Health Quality Collaborative (ACHQC) database was performed. Outcomes included risk of IH recurrence, 30-day surgical site infection (SSI), and 30-day surgical site occurrence (SSO).

RESULTS

We included 14,663 patients. Nicotine users who quit within 1 year of surgery had a 26% higher risk of IH recurrence compared to patients who quit more than a year before surgery or never users. Patients who quit using nicotine within 1 year of surgery had a 54% higher odds of SSI compared to former nicotine users who quit more than a year before surgery.

CONCLUSION

Former nicotine users with less than 1 year of nicotine use cessation before surgery exhibited worse outcomes than those with more than a year of cessation or no prior use.

Biomarkers and heterogeneous fibroblast phenotype associated with incisional hernia

Development of incisional hernia (IH) is multifactorial but inflammation and abdominal wall ECM (extracellular matrix) disorganization are key pathological events. We investigated if the differential expression of fibroblast biomarkers reflects the cellular milieu and the dysregulated ECM in IH tissues. Expression of fibroblast biomarkers, including connective tissue growth factor, alpha-smooth muscle actin (α-SMA), CD34 (cluster of differentiation 34), cadherin-11 and fibroblast specific protein 1 (FSP1), was examined by histology and immunofluorescence in the hernial-fascial ring/neck tissue (HRT) and hernia sack tissue (HST) harvested from the patients undergoing hernia surgery and compared with normal fascia (FT) and peritoneum (PT) harvested from brain-dead healthy subjects undergoing organ procurement for transplantation. The H&E staining revealed alterations in tissue architecture, fibroblast morphology, and ECM organization in the IH tissues compared to control. The biomarker for undifferentiated fibroblasts, CD34, was significantly higher in HST and decreased in HRT than the respective FT and PT controls. Also, the findings revealed an increased level of CTGF (connective tissue growth factor) with decrease in α-SMA in both HRT and HST compared to the controls. In addition, an increased level of FSP1 (fibroblast specific protein 1) and cadherin-11 in HRT with decreased level in HST were observed relative to the respective controls (FT and PT). Hence, these findings support the heterogeneity of fibroblast population at the laparotomy site that could contribute to the development of IH. Understanding the mechanisms causing the phenotype switch of these fibroblasts would open novel strategies to prevent the development of IH following laparotomy.

Fetal cardiomyocyte phenotype, ketone body metabolism, and mitochondrial dysfunction in the pathology of atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia diagnosed in clinical practice. Even though hypertension, congestive heart failure, pulmonary disease, and coronary artery disease are the potential risk factors for AF, the underlying molecular pathology is largely unknown. The reversion of the mature cardiomyocytes to fetal phenotype, impaired ketone body metabolism, mitochondrial dysfunction, and the cellular effect of reactive oxygen species (ROS) are the major underlying biochemical events associated with the molecular pathology of AF. On this background, the present manuscript sheds light into these biochemical events in regard to the metabolic derangements in cardiomyocyte leading to AF, especially with respect to structural, contractile, and electrophysiological properties. In addition, the article critically reviews the current understanding, potential demerits, and translational strategies in the management of AF.

Regulatory role of cardiomyocyte metabolism via AMPK activation in modulating atrial structural, contractile, and electrical properties following atrial fibrillation

The number of patients diagnosed with atrial fibrillation (AF) has been rising due to increased incidence, enhanced detection methods, and greater survival rates following diagnosis. Due to this increase, AF is now the most commonly diagnosed arrhythmia in clinical practice. AF is characterized by irregular, high-frequency contractions of atrial myocytes that lead to turbulent blood flow and the potential for thrombus formation, stroke, or heart failure. These high-frequency contractions of the atrial myocytes cause an imbalance between metabolic supply and demand. Although advances have been made in understanding the pathophysiology of AF, the etiology and underlying pathogenic mechanism remain unknown. However, recent evidence suggests that cardiomyocyte metabolism involving 5' AMP-activated protein kinase (AMPK) activation is altered in patients with AF. Here, we critically reviewed the current understanding of AMPK activation in AF and how it could affect structural, contractile, and electrophysiological cellular properties in the pathogenesis of AF.

Selected conditions associated with an increased incidence of incisional hernia: A review of molecular biology

BACKGROUND

Incisional hernias (IH) following a laparotomy, on average, occur in 10-20% of patients, however, little is known about its molecular basis. Thus, a better understanding of the molecular mechanisms could lead to the identification of key target(s) to intervene pre-and post-operatively.

METHODS

We examined the current literature describing the molecular mechanisms of IH and overlap these factors with smoking, abdominal aortic aneurysm, obesity, diabetes mellitus, and diverticulitis.

RESULTS

The expression levels of collagen I and III, matrix metalloproteinases, and tissue inhibitors of metalloproteases are abnormal in the extracellular matrix (ECM) of IH patients and ECM disorganization has an overlap with these comorbid conditions.

CONCLUSION

Understanding the pathophysiology of IH development and associated risk factors will allow physicians to identify patients that may be at increased risk for IH and to possibly act preemptively to decrease the incidence of IH.

Pulmonary Atypical Adenomatous Hyperplasia: Diagnostic and Therapeutic Implications

Lung cancer still remains one of the most common cancers throughout the world, especially in smokers. Adenocarcinoma is now the predominant histological type in many western countries. The etiology of adenocarcinoma is unknown, but evidence suggests that atypical adenomatous hyperplasia (AAH) may act as a precursor lesion. Here we present two case reports of patients diagnosed with AAH on biopsy, highlighting 1) available treatment strategies and 2) AAH’s progression to adenocarcinoma. A review of AAH is warranted as little literature is currently available regarding its treatment strategies, especially in light of its role as a precursor to adenocarcinoma.

In this review, we will address the following topics:

1. What is the pathophysiology of AAH? 2. What is the natural history of AAH and its risk of malignant transformation? 3. When is surgery recommended? 4. What is the role of stereotactic body radiotherapy (SBRT) in the rare patient who refuses surgery?

Novel understanding of high mobility group box-1 in the immunopathogenesis of incisional hernias

Introduction: Incisional hernias (IH) arise as a complication of patients undergoing laparotomy. Current literature has assessed the role of extracellular matrix (ECM) disorganization, alterations in type I and type III collagen, matrix metalloproteinases, and tissue inhibitors of metalloproteases on IH. However, there is limited information on the underlying molecular mechanisms that lead to ECM disorganization. Areas covered: We critically reviewed the literature surrounding IH and ECM disorganization and offer a novel pathway that may be the underlying mechanism resulting in ECM disorganization and the immunopathogenesis of IH. Expert opinion: High mobility group box-1 (HMGB-1), a damage-associated molecular pattern, plays an important role in the sterile inflammatory pathway and has been linked to ECM disorganization and the triggering of the NLRP3 inflammasome. Further research to investigate the role of HMGB-1 in the molecular pathogenesis of IH would be critical in identifying novel therapeutic targets in the management of IH formation.

The effect of carbachol on resting gastro-oesophageal sphincter pressure and serum gastrin in normal human subjects

With the purpose of investigating the mechanism of action behind the rise in gastro-oesophageal sphincter pressure induced by cholinergic activity, serum gastrin and sphincter pressure were recorded in 8 normal human subjects before and in relation to administration of carbachol. Carbachol was given subcutaneously in a dose of 4.5 mug per kg body weight. Mean sphincter pressure recorded 15, 30, and 45 minutes after administration of carbachol was significantly higher than the basal mean. The administration of carbachol did not lead to significant changes in serum gastrin and a relationship between serum gastrin and sphincter pressure was not demonstrable. It is concluded, that the carbachol-induced rise in the basal sphincter pressure is not dependent on an increase in serum gastrin, but probably attributable to either direct cholinergic stimulation of the receptors or a cholinergically enhanced sensitivity of the receptors for gastrin. Moreover, it is concluded that carbachol in individual dosages may be a suitable adjuvant in the medical treatment of patients with gastro-oesophageal reflux.