Near-sitting position and two-lung ventilation for endoscopic transthoracic sympathectomy

Evaluation of long-term outcome after lung lobectomy for canine non-neoplastic pulmonary consolidation via thoracoscopic or thoracoscopic-assisted surgery in 12 dogs

OBJECTIVE

To report outcomes of thoracoscopic (TL) and thoracoscopic-assisted lung lobectomy (TAL) for treatment of non-neoplastic pulmonary consolidation (PC) in dogs.

STUDY DESIGN

Retrospective case series.

ANIMALS

Twelve client-owned dogs.

METHODS

The medical records of 12 dogs that underwent TL or TAL for PC at 3 veterinary institutions between 2011 and 2020 were reviewed. Signalment, history, physical examination, diagnostics, days in hospital, anesthetic and procedure times, intraoperative/postoperative complications, conversion rates, duration of indwelling thoracic drain, and long-term outcomes were recorded.

RESULTS

Nine patients underwent a TL approach and 3 underwent TAL. In those that underwent TL, conversion to an intercostal thoracotomy was performed in 4 out of 9 dogs. Conversion was performed due to adhesions (n = 3) or poor visualization (1). Histopathologic examination was consistent with pneumonia due to an infectious process (n = 10), bronchioalveolar malformation with abnormal cilia (1), and left-sided cardiac insufficiency vs. pulmonary alveolar proteinosis (1). The mean duration of hospital stay was 4 days (range, 1-6 days). Complications occurred postoperatively in 7 dogs and included self-limiting hemorrhage (n = 3), self-resolving pneumothorax (2), incisional dehiscence (1), and severe dyspnea in a brachycephalic breed leading to euthanasia (1). For the 11 dogs that survived the perioperative period, there was no evidence of recurrence with a median follow up of 24 months (range, 5-120 months).

CONCLUSION

Thoracoscopic (TL) and thoracoscopic-assisted lung lobectomy (TAL) is a reasonable surgical approach in select dogs with PC.

CLINICIAL RELEVANCE

Conversion rates were higher than those historically reported for dogs undergoing thoracoscopic lung lobectomy for primary lung tumors.

Is two lung ventilation with artificial pneumothorax a better choice than one lung ventilation in minimally invasive esophagectomy?

Two lung ventilation (TLV) with artificial pneumothorax has been introduced into MIE for several years. A few researches have reported its clinical application, and proved its safety and feasibility. However, it is still controversial whether TLV with artificial pneumothorax is a better choice than one lung ventilation (OLV). Obviously, single lumen endotracheal tube is easy for intubation and intraoperative maintenance. Potential problems during intervention include hemodynamic changes, oxygenation, and air embolism. In this paper, present literature is reviewed about two and one lung ventilation in thoracoscopy, looking for clear conclusions for future application.

Managing hypoxemia during minimally invasive thoracic surgery

An ever-increasing number of thoracic procedures are being performed through minimally invasive techniques. Although the incidence of hypoxemia during one-lung ventilation (OLV) has decreased over the years, it remains an issue in roughly 10% of cases. Algorithms for the management of OLV hypoxemia have to be adapted to the thoracoscopic approach, in particular the need for optimal surgical exposure. With appropriate planning and caution, most of the treatment modalities for OLV hypoxemia can be applied to the thoracoscopy setting, with some modifications.

Right or left first during bilateral thoracoscopy?

BACKGROUND

Endoscopic thoracic sympathectomy (ETS) is now an established surgical technique for treatment of palmar hyperhidrosis that is performed under general anesthesia with positive pressure ventilation via either an endotracheal tube or a double lumen endobronchial tube. This is a bilateral disease that requires the division of the right and left thoracic sympathetic chain. The aim of this study was to compare the hemodynamic changes using a left capnothorax first versus right a capnothorax first surgical approach using a single lumen endotracheal tube in patients undergoing bilateral ETS. Lung collapse was achieved by carbon dioxide insufflation.

METHODS

Forty patients of both sexes aged 18-30 years and of American Society of Anesthesiologists grade I were randomly assigned to undergo bilateral ETS. Patients were divided into two groups. Group L comprised left capnothorax first, followed by right capnothorax (n = 20). Group R comprised right capnothorax first, followed by left capnothorax (n = 20). The anesthesia technique was standardized for all patients. Cardiovascular variables were determined during the procedure every minute. Statistical analysis was performed by independent-sample t test and Pearson's chi-square test.

RESULTS

There was a significant (P < 0.05) mean percentage decrease in systolic blood pressure in group L compared to group R. Similarly, the mean percentage decrease in diastolic blood pressure in group L was significant compared to group R (P < 0.05). Seven patients in group L developed bradycardia, but this was not found to be statistically significant.

CONCLUSIONS

When the left capnothorax first approach was used, there was significant hypotension, compared to a right capnothorax first thoracoscopy. We thus recommend that right capnothorax should be performed first in cases of bilateral ETS.

Anesthesia for thoracoscopic surgery

Anesthesia for thoracoscopy is based on one lung ventilation. Lung separators in the airway are essential tools. An anatomical shunt as a result of the continued perfusion of a non-ventilated lung is the principal intraoperative concern. The combination of equipment, technique and process increase risks of hypoxia and dynamic hyperinflation, in turn, potential factors in the development of an unusual form of pulmonary edema. Analgesia management is modelled on that shown effective and therapeutic for thoracotomy. Perioperative management needs to reflect the concern for these complex, and complicating, processes to the morbidity of thoracoscopic surgery.

Cardiovascular changes during drainage of pericardial effusion by thoracoscopy

BACKGROUND

Cardiovascular changes during drainage of pericardial effusion are not well understood, and most studies are of systemic effects and not of right ventricular performance. Thoracoscopy is not widely used to drain pericardial effusions because of haemodynamic changes in relation to the use of single lung ventilation.

PATIENTS AND METHODS

We studied 16 patients undergoing partial pericardiectomy for pericardial effusion, using videothoracoscopy with a low-pressure pneumothorax (6 mm Hg). Cardiac output was measured by thermodilution with the patient anaesthetized in the supine position before the procedure; in the right lateral position after a low-pressure pneumothorax had been established; and after drainage of the pericardial effusion.

RESULTS

Before the procedure, cardiac output was low and central venous pressure and pulmonary artery occlusion pressure were increased. Systemic vascular resistance and arterial blood pressure were within normal limits. Cardiac filling pressure and pulmonary arterial pressure increased during the pneumothorax. After the drainage cardiac index increased and systemic and pulmonary vascular resistances were reduced.

CONCLUSIONS

Pericardial effusion reduces right ventricular distensibility, right and left systolic ventricular function, and cardiac output. Anaesthesia with mechanical ventilation and a low-pressure pneumothorax do not affect the circulation greatly. Drainage of the pericardial effusion allows cardiac distensibility to increase and cardiac performance changes to allow increased ejection.

Selective lobar collapse for video-assisted thoracic surgery

BACKGROUND

Video-assisted thoracic surgery (VATS) is conventionally performed under single-lung ventilation. A small proportion of patients are often excluded from undergoing VATS because of their inability to tolerate single-lung ventilation. We describe a simple technique of selective lobar lung collapse that may help to recruit additional, selected patients for VATS.

METHODS

We use a standard suction catheter placed under bronchoscopic guidance to the target lobar bronchus through a single-lumen endotracheal tube. The catheter is left open to air, or suction can be applied to facilitate lobar collapse. The remaining lobe of the same lung can be ventilated throughout surgery. Surgery is performed using standard VATS techniques.

RESULTS

Using this technique we have successfully performed VATS on 63 chest sides in 35 patients. The procedures performed included thoracodorsal sympathectomies (n = 28), mechanical pleurodesis procedures (n = 3), mediastinal and pleural biopsies (n = 2), and lung wedge resections (n = 2). We encountered no mortality or morbidity in all cases.

CONCLUSIONS

This technique is simple and safe and requires no expensive disposable devices. Although not essential for most patients undergoing VATS, it deserves to be in the armamentarium of the thoracic surgeon. Further studies will be required to better define its application in clinical practice.

Anaesthesia for thoracoscopic surgery

The surgical requirement for thoracoscopy is a good view of the contents of the thorax. This is achieved by capitalizing on natural consequences and the skills of anaesthesiologists to produce a pneumothorax and collapse the ipsilateral lung--a process that is commonly enhanced by insufflating carbon dioxide. Insufflating CO2 to actively promote lung collapse creates the dynamics of a tension pneumothorax. Complications are clinically insignificant if CO2 is used judiciously. There is a body of experience using ordinary endotracheal tubes and two-lung ventilation. Techniques of one-lung ventilation are more widely reported. All the factors known to contribute to the significant increase in shunt fraction associated with one-lung ventilation apply. The manoeuvre of collapsing a lung is no longer regarded as benign. Chemical attempts to produce a reversible post-pneumonectomy pulmonary circulation have not been shown to be an improvement. Post-operative pain can be severe. The mechanism is not defined but it differs from that associated with thoracotomy. Epidural analgesia and opioids may be required. Chronic pain syndromes have been described as complications.

Haemodynamic changes during thoracoscopic surgery the effects of one-lung ventilation compared with carbon dioxide insufflation

We investigated the haemodynamic and respiratory effects of one-lung ventilation and carbon dioxide insufflation in 13 adult patients undergoing video-assisted thoracoscopy. Cardiorespiratory variables were determined during carbon dioxide insufflation at intrahemithoracic pressures of 5, 10 and 15 mmHg, and after 5 and 15 min of one-lung ventilation. Carbon dioxide insufflation was associated with a clear deterioration in circulatory function. The cardiac index decreased subsequent to increasing intrathoracic pressures. The mean cardiac index (SD) at pressures of 10 and 15 mmHg was 1.86 (0.39) and 1.52 (0.46), respectively, and may be compared with the reduced venous return consistent with tension pneumothorax. One-lung ventilation did not affect haemodynamic variables but reduced arterial oxygenation indices (PaO2/FIO2) from 424.29 (160.79) after induction of anaesthesia, to 207.72 (125.50) after 5 min and 172.04 (72.03) after 15 min of one-lung ventilation, respectively. The oxygenation index was not influenced by intrahemithoracic carbon dioxide insufflation. One-lung ventilation via a double-lumen endobronchial tube is safe and convenient for video-assisted thoracoscopic surgery. It has no further consequences on haemodynamic variables, whereas the compression of the lung by carbon dioxide insufflation may cause circulatory dysfunction.