Evaluation of the combined laparoscopic and mediastinoscopic esophagectomy technique

BACKGROUND

Laparoscopic esophagectomy is technically difficult especially during dissection in the upper mediastinum. This limitation may be surpassed with the help of mediastinoscopy or of the recently introduced robotic surgical systems. The aim of the present study was to evaluate in an experimental porcine model the feasibility of the combined laparoscopic and mediastinoscopic transhiatal esophagectomy technique and to compare it with the robotic-assisted transhiatal and conventional approaches.

MATERIALS AND METHODS

Transhiatal esophagectomy was performed in Landrace pigs under general anesthesia using three different techniques: Group A (n = 9): combined laparoscopic and mediastinoscopic, group B (n = 4): robotic-assisted and group C (n = 8): conventional "open". The feasibility, difficulty and accuracy of the procedure along with operative time, blood loss, intraoperative incidents and overall satisfaction of the surgical team were assessed for each technique.

RESULTS

Operations in group A were feasible and reproducible. Although the procedure was technically difficult, the constant view on the operative field was highly appreciated by the operative team and facilitated an accurate and safe dissection. The main intraoperative complications were related to the side-effects of tension pneumothorax accompanying pleural injuries. In group B the features of the robotic system reduced the difficulty of dissection and obviated the need for mediastinoscopy. Operations in group C were quick and almost incident-free, facilitated also by the particularities of the animal model that could not reproduce identically the clinical situation.

CONCLUSIONS

The combined laparoscopic and mediastinoscopic esophagectomy technique is feasible and offers certain advantages over the open approach while the robotic-assisted approach is an emerging less difficult alternative. Further studies are required to establish whether the advantages of minimally-invasive approach compensate for the increased technical difficulty and prolonged operative time.

Bombesin receptors in distinct tissue compartments of human pancreatic diseases

Overexpression of receptors for regulatory peptides in various human diseases is reportedly of clinical interest. Among these peptides, bombesin and gastrin-releasing peptide (GRP) have been shown to play a physiological and pathophysiological role in pancreatic tissues. Our aim has been to localize bombesin receptors in the human diseased pancreas to identify potential clinical applications of bombesin analogs in this tissue. The presence of bombesin receptor subtypes has been evaluated in specimens of human pancreatic tissues with chronic pancreatitis (n = 23) and ductal pancreatic carcinoma (n = 29) with in vitro receptor autoradiography on tissue sections incubated with 125I-[Tyr4]-bombesin or the universal ligand 125I-[D-Tyr6, beta-Ala11, Phe13, Nle14]-bombesin(6-14) as radioligands and displaced by subtype-selective bombesin receptor agonists and antagonists. GRP receptors were identified in the pancreatic exocrine parenchyma in 17 of 20 cases with chronic pancreatitis. No measurable bombesin receptors were found in the tumor tissue of ductal pancreatic carcinomas, however, GRP receptors were detected in a subset of peritumoral small veins in 19 of 29 samples. Moreover, residual pancreatic islets in these tissues were shown to express the BB3 receptor subtype. These data demonstrate the presence of bombesin receptors in three distinct tissue compartments of the pancreas, namely GRP receptors in the exocrine parenchyma in chronic pancreatitis and in peritumoral vessels around ductal pancreatic carcinomas, and BB3 receptors in residual pancreatic islets. Such a selective expression of bombesin receptor subtypes in pancreatic tissues may not only be of pathophysiological significance but may represent the basis for potential diagnostic and therapeutic clinical applications of bombesin analogs, including GRP receptor scintigraphy to differentiate chronic pancreatitis from ductal pancreatic carcinoma.