Metabolic changes in the lower esophageal sphincter influencing the result of anti-reflux surgical interventions in chronic gastroesophageal reflux disease

AIM: With the availability of a minimally invasive approach, anti-reflux surgery has recently experienced a renaissance as a cost-effective alternative to life-long medical treatment in patients with gastroesophageal reflux disease (GERD). We are not aware of the fact whether reflux episodes causing complaints for a long time i.e., at least for one year are associated with metabolic changes in the lower esophageal sphincter, and if so,whether these may influence functional results achieved after anti-reflux surgery.METHODS: Between 1 January 2001 and 31 December 2002 we performed anti-reflux surgery on 79 patients.Muscle samples were taken from the lower esophageal sphincter (LES) in 33 patients during anti-reflux surgery.Inclusion criteria were: LES resting pressure below 10 mmHg and a marked, pH proven acid exposure to the esophagus of at least one year's duration, causing subjective complaints and requiring continuous proton pump inhibitor treatment. Control samples were obtained from muscle tissue in the gastroesophageal junction that had been removed from 17 patients undergoing gastric or esophageal resection. Metabolic and lysosomal enzyme activities and special protein concentrations 16 parameters in total were evaluated in tissue taken from control specimens and tissue taken from patients with GERD. The biochemical parameters of these intra-operative biopsies were used to correlate the results of anti-reflux operations (Visick I and II-III).RESULTS: In the reflux-type muscle, we found a significant increase of the energy-enzyme activities e.g., creatine kinase, lactate dehydrogenase, β-hydroxybutyrate dehydrogenase, and aspartate aminotransaminase-. The concentration of the structural protein S-100 and the myofibrillar protein troponin I were also significantly increased. Among lysosomal enzymes, we found that the activities of cathepsin B, tripeptidyl-peptidase I, dipeptidylpeptidase II, β-hexosaminidase B, β-mannosidase and β-galactosidase were significantly decreased as compared to the control LES muscles. By analyzing the activity values of the 9 patients in Visick groups Ⅱ and Ⅲ at two months post-surgery, we found a significant increase in the activity of the so-called energy-enzyme values and in the concentration of structural and myofibrillar proteins as compared to the rest of the reflux patients.CONCLUSION: Our results call attention to the metabolic changes that occurred in the LES muscles of reflux patients. The developing hypertrophy-like changes of LES muscles may be a reason for complaints after anti-reflux surgery, which consisted mainly of reports of persisting dysphagia.

Significance and prognostic value of lysosomal enzyme activities measured in surgically operated adenocarcinomas of the gastroesophageal junction and squamous cell carcinomas of the lower third of esophagus

AIM: To establish whether there are fundamental differences in the biochemistries of adenocarcinomas of the gastroesophageal junction (GEJ) and the squamous cell carcinomas of the lower third of the esophagus (LTE).METHODS: Between February 1, 1997 and February 1,2000, we obtained tissue samples at the moment of resection from 54 patients for biochemical analysis. The full set of data could be comprehensively analyzed in 47 of 54 patients' samples (81%). Of these, 29 were adenocarcinomas of the GEJ Siewert type Ⅰ (n = 8), type Ⅱ (n = 12), type Ⅲ (n = 9), and 18 presented as squamous cell carcinomas of the LTE. We evaluated the mean values of 11-lysosomal enzyme and 1-cytosol protease activities of the tumorous and surrounding mucosae as well as their relative activities, measured as the ratio of activity in tumor and normal tissues from the same patient.These data were further analyzed to establish the correlation with tumor localization, TNM stage (lymph-node involvement), histological type (papillary, signet-ring cell,tubular), state of differentiation (good, moderate, poor),and survival (≤24 or ≥24 mo).RESULTS: In adenocarcinomas, the activity of α-mannosidase (AMAN), cathepsin B (CB) and dipeptidyl-peptidase Ⅰ (DPP Ⅰ) increased significantly as compared to the normal gastric mucosa. In squamous cell carcinomas of the esophagus, we also found a significant difference in the activity of cathepsin L and tripeptidyl-peptidase I in addition to these three. There was a statistical correlation of AMAN,CB, and DPP Ⅰ activity between the level of differentiation of adenocarcinomas of the GEJ and lymph node involvement,because tumors with no lymph node metastases histologically confirmed as well-differentiated, showed a significantly lower activity. The differences in CB and DPP Ⅰ activity correlated well with the differences in survival rates, since the CB and DPP Ⅰ values of those who died within 24 mo following surgical intervention were significantly higher than of those who survived for 2 years or more.CONCLUSION: Adenocarcinomas of the GEJ form a homogenous group from a tumor-biochemical aspect,and differ from the biochemical characteristics of squamous cell carcinomas of the LTE on many points.When adenocarcinomas of the GEJs are examined at the preoperative phase, the ratio of the performed AMAN,CB, and DPP Ⅰ enzymatic activity of the tissue sample from the tumor and adjacent intact mucosa within 2 cm of the tumor may have a prognostic value even in the preoperative examination period, and may indicate that ranking of these patients into the neo-adjuvant treatment group should be considered.

Cryopreservation of the Trachea Can Reduce Its Antigenicity in Various Species

Background: Cryopreserved tracheal allograft has been used successfully for esophageal replacement in the canine model. The working hypothesis was cryopreservation decreases antigenicity but epithelial desquamation remains. However, cryopreservation of human tracheal samples collected at tracheostomy, resulted in no significant desquamation. The aim of this study was to examine the extent of desquamation of the epithelial layer of cryopreserved animal tracheas and find a reason for decreased antigenicity of cryopreserved canine and pig’s trachea. Methods: 5 cm long tracheal segments were removed from 6 dogs and 125 pigs and stored in liquid nitrogen for 21 days. Cross section samples were taken from the end of the segment, 1 cm from the end and at the middle of the segment. Histological examination was performed using haematoxyllineosin and MHC-II antigen specific antibody staining. Changes in histological structure were analyzed. Results: General histological morphology of samples changed after cryopreservation. The percentage of intact epithelium and the overall intensity of immune-staining increased significantly from the ends to the middle of the segments, but the intensity of immune-staining showed no difference in the remaining epithelial cells. Conclusion: Cryopreservation damages the epithelial cells, but does not influence the cell’s antigenicity or cause desepithelisation. The main effect is a retraction of the epithelial layer from the ends to the midpart and this effect may be protection against organ rejection. Based on our canine and pig results a 5 cm, long tracheal segment seems to be a promising organ for human esophageal replacement.