Chloride Conductance,Nasal Potential Difference and Cystic Fibrosis Pathophysiology

Purpose

Cystic fibrosis (CF) is a multisystem genetic disease caused by dysfunction of the epithelial anionic channel Cystic Fibrosis Transmembrane conductance Regulator (CFTR). Decreased mucociliary clearance because of thickened mucus is part of the pulmonary disease pathophysiology. It is controversial if the thickened airway surface liquid (ASL) is caused by the deficient chloride secretion and excessive sodium (through ENaC) and water hyperabsorption from the periciliar fluid or by the lack of bicarbonate secretion with relative acidification of the ASL. Correlations between the magnitude of in vivo chloride conductance with phenotypic characteristics and CF genotype can help to elucidate these mechanisms and direct to new treatments.

Methods

Nasal potential difference was measured in 28 CF patients (age from 0.3 to 28 year) and correlated with pulmonary function, pancreatic phenotype, pulmonary colonization and genotype severity.

Results

The CFTR-chloride conductance was better in older patients (r = 0.40; P = 0.03), in patients with better pulmonary function (r = 0.48; P = 0.01), and was associated with genotype severity. Higher chloride diffusion in the presence of a favorable chemical gradient was associated with Pseudomonas aeruginosa negativity (P < 0.05). More negative NPDmax was associated with pancreatic insufficiency (P < 0.01) as well with genotype severity, but not with the pulmonary function.

Conclusions

The anion permeability through CFTR, mainly chloride, but bicarbonate as well, is the most critical factor in CF airway pathophysiology. Treatments primarily directed to correct CFTR function and/or airway acidity are clearly a priority.

     

Perforated duodenal diverticulum: Surgical treatment and literature review

INTRODUCTION

Duodenum is the second most frequent location for a diverticulum in the digestive tract. Complications are rare and perforation was only reported in less than 200 cases.

PRESENTATION OF CASE

A 79-year-old female was admitted to Emergency Department with abdominal pain and vomiting for the last 24 h. A CT scan was performed and moderated extra-luminal air was identified. During surgery a fourth portion perforated duodenal diverticulum was diagnosed and duodenal resection was performed.

DISCUSSION

First reported in 1710, the incidence of duodenal diverticula can be as high as 22%. Nevertheless complications are extremely rare and include haemorrhage, inflammation, compression of surrounding organs, neoplastic progression, cholestasis and perforation.As perforations are often retroperitoneal, symptoms are nonspecific and rarely include peritoneal irritation, making clinical diagnose a challenge.CT scan will usually present extra-luminal retroperitoneal air and mesenteric fat stranding, providing clues for the diagnosis.Although non-operative treatment has been reported in selected patients, standard treatment is surgery and alternatives are diverse including diverticulectomy or duodenopancreatectomy.

CONCLUSION

Perforated diverticula of the fourth portion of the duodenum are extremely rare and current evidence still supports surgery as the primary treatment modality.     

Multi-staged flap reconstruction for complex radiation thoracic ulcer

INTRODUCTION

Chest wall reconstruction due to previous radiation therapy can be challenging and complex, requiring a multidisciplinary approach.

PRESENTATION OF CASE

The authors present the case of a 84-year-old woman with a right chest wall radionecrosis ulcer, that was submitted to an ablative surgery resulting in a full-thickness defect of 224 cm², firstly reconstructed with a pedicled omental flap. Due to partial flap necrosis, other debridements and chest wall multi-staged flap reconstruction were performed.

DISCUSSION

This case highlights that the reconstructive choice should be individualized and dependent on patient and local factors. The authors advise that surgical team should work closely and be well versed in chest wall reconstruction with a variety of pedicled flaps, when a complication occurs.

CONCLUSION

A multi-staged flap reconstruction could be a salvage procedure for the coverage of complex, great and complicated chest wall defects due to previous radiation therapy.