No abstract

Thanks to the experience gained through the improvement of video-assisted thoracoscopic surgery (VATS) technique, and the enhancement of surgical instruments and high-definition cameras, most pulmonary resections can now be performed by minimally invasive surgery. The future of the thoracic surgery should be associated with a combination of surgical and anaesthetic evolution and improvements to reduce the trauma to the patient. Traditionally, intubated general anaesthesia with one-lung ventilation was considered necessary for thoracoscopic major pulmonary resections. However, thanks to the advances in minimally invasive techniques, the non-intubated thoracoscopic approach has been adapted even for use with major lung resections. An adequate analgesia obtained from regional anaesthesia techniques allows VATS to be performed in sedated patients and the potential adverse effects related to general anaesthesia and selective ventilation can be avoided. The non-intubated procedures try to minimize the adverse effects of tracheal intubation and general anaesthesia, such as intubation-related airway trauma, ventilation-induced lung injury, residual neuromuscular blockade, and postoperative nausea and vomiting. Anaesthesiologists should be acquainted with the procedure to be performed. Furthermore, patients may also benefit from the efficient contraction of the dependent hemidiaphragm and preserved hypoxic pulmonary vasoconstriction during surgically induced pneumothorax in spontaneous ventilation. However, the surgical team must be aware of the potential problems and have the judgement to convert regional anaesthesia to intubated general anaesthesia in enforced circumstances. The non-intubated anaesthesia combined with the uniportal approach represents another step forward in the minimally invasive strategies of treatment, and can be reliably offered in the near future to an increasing number of patients. Therefore, educating and training programmes in VATS with non-intubated patients may be needed. Surgical techniques and various regional anaesthesia techniques as well as indications, contraindications, criteria to conversion of sedation to general anaesthesia in non-intubated patients are reviewed and discussed.

No abstract

As we gain more experience over time, with more cases performed each year and less invasive approaches, results improve in terms of less surgical time and more extended lymphadenectomies. Furthermore, we have observed a clear evolution in our surgical approach to a less invasive 2-port approach. In selected cases we have implemented the single-port lobectomy.

Calculating the time required for a diffusing object to reach a small target within a larger domain is a feature of a large class of modeling and simulation efforts in biology. Here, we are motivated by the motion of a T cell of the immune system seeking a particular antigen-presenting-cell within a large lymph node. The precise nature of the cell motion at the outer boundary of the lymph node is not completely understood in terms of how cells choose to remain within a given lymph node, or exit. In previous work, we and others have studied diffusive motion to a small trap. We extend this previous work to analyze models where the diffusing object may exit the outer boundary of the domain (in this case, the lymph node). This is modeled by a Robin boundary condition on the surface of the lymph node. For the general problem of small traps inside a 3-D domain that has a partially sticky or absorbent domain boundary, the method of matched asymptotic expansions is used to calculate the mean and variance of the conditional first passage time for the T cell to reach a specific target trap. Our results are illustrated explicitly for the idealized situation of a spherical lymph node containing small spherically-shaped traps, and are verified for a radially symmetric geometry with one trap at the origin where exact solutions are available. Mathematically, our analysis extends previous work on the calculation of the MFPT by allowing for a sticky boundary and by calculating conditional statistics of the diffusion process. Finally, our results are interpreted and applied to the context of T cell biology.