Minimally invasive is the direction of surgical development. In recent years, Video-assisted thoracoscopic surgery (VATS ) VATS has developed rapidly in the field of general thoracic surgery, and its surgical indications have been further expanded, and it has been widely used in the diagnosis and treatment of various diseases in the chest, and has achieved good clinical results. The progress of VATS in general thoracic surgery is introduced.
1.Pleural diseases
1.1 abscess chest For acute abscess chest, a closed chest drain should be placed at an early stage for adequate drainage, and for chronic abscess chest, a dissection should be performed. At present, VATS is mainly used for the treatment of subacute abscess chest (disease duration less than 3 weeks), which can separate adhesions under direct vision, break the fibrous separation, completely remove the fluid and pus moss and necrotic tissue, promote lung reopening, and drain the tube in the best position. It has a success rate of 72%-90%, comparable to conventional open-heart surgery, and has less trauma, faster recovery, and a significantly shorter hospital stay than the latter. If intraoperative adhesions are found to be serious and fiberboard peeling is difficult, it should be promptly referred for open thoracotomy.
1.2 Malignant pleural effusion The traditional treatment for malignant pleural effusion is repeated thoracentesis or closed drainage, which has a short-term recurrence rate of more than 80% and may cause complications such as fluid separation, pneumothorax and abscess chest. At present, pleural fixation under VATS is used to treat malignant pleural fluid: it can separate pleural adhesions and fibrous separation under direct vision and drain pleural fluid thoroughly; pleural biopsy can be performed at the same time to clarify the histological diagnosis; on the premise of ensuring good lung dilation, talcum powder can be sprayed evenly in the pleural cavity or the pleura can be extensively electrocoagulated.
1.3 Celiac disease The incidence of celiac disease is 0.5-2%, commonly caused by tumor and trauma, of which about 0.5% is secondary to surgical injury, and the latter is most common in esophageal surgery (2.9%). Celiac disease has a mortality rate of 50% if left untreated. It is usually treated conservatively first, and some patients can heal spontaneously, while the rest need surgery. There is no clear standard about the timing and mode of surgery.
Some people advocate that after two weeks of conservative treatment, surgery is necessary if the drainage is still greater than 500 ml/d. Ligation of the thoracic duct on the diaphragm through the original incision or right-sided open chest used to be one of the main procedures. In recent years, VATS has been used in the treatment of celiac disease. It has a wide field of view and its magnification function helps to identify the thoracic duct, and after identifying the location of the injury, both ends are clamped with titanium clips; if the adhesions of the tissues around the thoracic duct are serious or multiple branches are injured, a large piece of tissue between the odd vein and the aorta containing the main trunk of the thoracic duct should be ligated on the diaphragm;
1.4 Spontaneous pneumothorax For a long time, the first choice of treatment for spontaneous pneumothorax is closed chest drainage, but the recurrence rate is 20%, and it is proportional to the number of attacks: the recurrence rate of the second and third attacks can be as high as 60% and 80% or more. Although the long-term follow-up results of traditional open-chest surgery show a recurrence rate of less than 5%, the high complications associated with open-chest surgery have led physicians not to consider surgical treatment as a last resort.
Currently, it is generally accepted that VATS can replace open chest surgery as the gold standard for the treatment of spontaneous pneumothorax. The indications are: recurrent spontaneous pneumothorax, persistent lung leakage >5 days, bilateral pneumothorax or associated hemothorax, combined with pulmonary blister, special occupations (pilots, divers, etc.) or in the environment lacking medical facilities. Commonly used methods include: endoscopic suture cutter (Endo-path) wedge resection, laser or argon (Nd:YAY) electrocautery, electrocautery, endoloop ligation, etc;
Most advocate concurrent pleural fixation, which includes (apical) wall pleurodesis, friction, electrocautery, and talcum powder spray. The results of VATS for spontaneous pneumothorax are less traumatic, less painful, and have faster recovery than open thoracotomy, and the long-term follow-up results are similar to those of open thoracotomy. Secondary spontaneous pneumothorax is mostly seen in middle-aged and elderly people, and most of them have diffuse emphysema and different degrees of lung function impairment, so the above advantages of VATS are difficult to be reflected. Its treatment should be based on the severity of the primary disease and the patient’s general condition, and the operation should be performed with caution.
2.Pulmonary diseases
2.1 Interstitial lung disease Most of the various clinical diagnostic methods lack specificity; only open-chest lung biopsy has a high confirmation rate and has long been considered the gold standard for diagnosis. Traditionally, a small incision is made into the chest, and a biopsy of the suspicious lung is performed in combination with preoperative CT localization. The main disadvantage of this procedure is that it is not possible to perform multiple biopsies of different lung parenchyma due to the limitation of the surgical incision, thus affecting the positive rate of biopsy and the accuracy of diagnosis.
Compared with open lung biopsy, the main advantage of VATS lung biopsy is that it has a wide field of view and allows direct exploration of the lung, mediastinum, and mural pleura, as well as the ability to take multiple lung tissue biopsies at different sites according to the diagnostic requirements, increasing the diagnostic positivity rate. In addition, it is less invasive, with fewer complications and faster recovery. This is particularly important in patients with diffuse interstitial lung disease combined with impaired lung function. Most patients with chronic interstitial lung disease tolerate one-lung ventilation and general anesthesia, and the diagnostic accuracy of VATS biopsy is 94%-100%.
2.2 Isolated pulmonary nodules Isolated pulmonary nodules are defined as round or oval nodules in a single lung ≤4 cm, surrounded by normal lung tissue, without hilar lymph node enlargement or pulmonary atelectasis. The traditional method of diagnosis is fibrinoscopy, which has a diagnostic accuracy of 10% for nodules <2 cm in diameter and 40%-50% for those >2 cm. Another method is transthoracic needle aspiration biopsy (TTN), which has an overall diagnostic rate of 43%-97% for peripheral nodules, but still cannot completely avoid complications such as pneumothorax and pulmonary tissue hematoma, and has a high false-negative rate with little tissue obtained.
The indications for VATS in the diagnosis and treatment of isolated pulmonary nodules are: pulmonary nodules without calcification located in the peripheral part of the lung or in the subpleural layer of the lung fissure, ≤3 cm in diameter, which cannot be clearly diagnosed by other tests, and lesions larger than 3 cm in diameter should undergo open thoracotomy. One of the keys to surgery is the precise localization of the intrapulmonary nodule.
After accurate localization of the nodule, pulmonary wedge resection is usually performed using an endoscopic suture cutter, and the next treatment option is decided based on the results of the rapid pathological examination: if the nodule is benign, then VATS ends as a therapeutic surgical approach; if the lesion is malignant, further exploration of the mediastinal lymph nodes is required, and then a decision is made whether to perform a standard open thoracotomy or VATS lobectomy, taking into account the general condition of the patient.
2.3 Chronic Branch and emphysema Cooper et al. achieved encouraging results with bilateral lung decompression via a median sternotomy in strictly selected COPD patients. In recent years, VATS has been used to perform pulmonary decompression with some success, but there are still controversies regarding its case selection (indications, contraindications), procedure (open chest, median sternotomy, VATS), method of lung resection (suture cutter, laser), unilateral or bilateral, and evaluation criteria of surgical results.
2.4 Lung cancer At present, the controversy on whether VATS can replace conventional open thoracotomy for radical resection of early-stage lung cancer focuses on the following four points: 1) whether VATS for hilar dissection is technically safe; 2) whether radical resection of the tumor can be accomplished; 3) the high cost of surgery, especially the cost of disposable consumables; and 4) whether it is superior to conventional open thoracotomy.
Selection of surgical indications.
With the improvement of surgical techniques, surgical indications are bound to be a changing process, and some relative contraindications are gradually changing to indications. At present, the generally accepted indications are Stage I, early peripheral lung cancer with a diameter of 5 cm or less, no obvious mediastinal hilar lymph node enlargement, and no obvious pleural thickening and calcification.
Controversial indications: Stage II: central type lung cancer unrelated to lobe bronchus, no obvious calcification of lymph nodes in the summary area, lymph nodes in the hilar and mediastinal areas less than 1.5 cm and not fused into a mass and some IIIa patients. There are reports of complex thoracic surgeries such as total thoracoscopic sleeve lobectomy, combined chest wall resection, total pneumonectomy, tracheoplasty and partial lobectomy performed. Wang J et al. concluded that 80% of current thoracic surgeries can be performed thoracoscopically.
At the same time, thoracoscopy can enable patients over 80 years old with FEV1<0.8 or FEV1<50%, which are contraindicated for traditional open thoracic surgery, to get the opportunity to operate. Therefore, we say that the indications for total laparoscopic surgery are dynamic and the surgeon reasonably chooses the appropriate surgical modality based on standardized treatment. The surgery can be done either fully lumpectively or lumpectively assisted, but the current direction should be total lumpectomy lobectomy.
Since the advent of total lumpectomy, the safety and feasibility of the procedure have been questioned, but with the continuous development of the procedure, the conclusion of this debate has been reached. 2009, Yan et al. published a meta-analysis containing 21 studies of thoracoscopic and open-chest treatment of early-stage lung cancer, showing that after 5 years of follow-up, the local recurrence rate was not significantly higher in the thoracoscopic group compared with the open-chest group.
A systematic review by Whitson et al. in 2008 included data on more than 6300 thoracoscopic and open-chest surgeries. Patients in the thoracoscopic group had significantly lower surgical complications, postoperative drainage time, and length of hospital stay than those in the open-chest surgery group. The long-term survival rate was higher than that of the open-chest group, especially the 4-year survival rate was 17% higher in absolute terms. It is important to note that these thoracoscopic surgery groups included a significant proportion of patients with early and less mature techniques.
The first recent prospective, multicenter clinical trial (CALGB39802) aimed at evaluating the safety and feasibility of thoracoscopic lobectomy for early-stage lung cancer concluded that thoracoscopic surgery was safe and feasible, with reduced complications from shorter chest tube retention and similar survival. No bleeding-related deaths occurred in the chest. The perioperative mortality rate was 0.8%. There is now every reason to believe that total thoracoscopic lobectomy is a safe and feasible procedure.
The safety and feasibility of the procedure have been questioned, but as the procedure continues to evolve, the debate has largely come to a conclusion. 2009 Yan et al. published a meta-analysis of 21 studies of thoracoscopic and open lung cancer treatment in early stage lung cancer, showing that after 5 years of follow-up, the local recurrence rate was not significantly higher in the thoracoscopic group compared to the open group. A systematic review by Whitson et al. in 2008 included data on more than 6300 thoracoscopic and open-chest surgeries.
Patients in the thoracoscopic group had significantly lower surgical complications, postoperative drainage time, and length of hospital stay than those in the open-chest surgery group. The long-term survival rate was higher than that of the open-chest group, especially the 4-year survival rate was 17% higher in absolute terms. It is important to note that these thoracoscopic surgery groups included a significant proportion of patients with early and less mature techniques. The first recent prospective, multicenter clinical trial (CALGB39802) with the goal of evaluating the safety and feasibility of thoracoscopic lobectomy for early-stage lung cancer concluded that thoracoscopic surgery was safe and feasible, with reduced complications from short chest tube retention and similar survival.
McKenna reported the largest group of patients with lumpectomy lobectomies to date, with only 7 of 1100 requiring intermediate open chest without bleeding-related deaths. The perioperative mortality rate was 0.8%. There is now every reason to believe that total thoracoscopic lobectomy is a safe and feasible surgical procedure.
3. Mediastinal disease
3.1 Biopsy of mediastinal masses Most mediastinal tumors should be surgically resected, but in some cases, such as clinical diagnosis of suspected lymphoma or for preoperative staging of lung cancer patients for treatment planning, a biopsy of the mediastinal tumor or enlarged lymph node is required to determine the nature. For enlarged lymph nodes in the paratracheal and subserosal regions (groups 2, 3, 4 and 7) as shown on preoperative CT, most of them can be confirmed by cervical mediastinoscopy.
It is simple, safe, effective and remains the gold standard for evaluation of upper mediastinal lymph nodes. A transsternal parasternal anterior mediastinotomy can be performed to explore the main pulmonary window and para-aortic lymph nodes (groups 5 and 6). However, neither of the first two can evaluate the paraesophageal, inferior pulmonary ligament, and hilar lymph nodes (groups 8, 9, and 10). VATS can explore groups 5-10 lymph nodes via the left side and the entire group via the right side, and can be used as a complementary tool to transcervical mediastinoscopy.
VATS is more advantageous in the following cases: it can simultaneously detect the presence of pleural dissemination, intrapulmonary metastases, T4 tumors and manage malignant pleural effusions; for suspected highly malignant tumors such as lymphoma, sufficient tissue can be taken from multiple points to make a definite diagnosis. If the biopsy result is negative, VATS lobectomy or open thoracotomy can be performed immediately; if the diagnosis of unresectable malignant tumor or non-surgical disease is confirmed, local or systemic treatment can be performed early to avoid unnecessary complications caused by non-radical open thoracotomy
3.2 Anterior mediastinum
3.2.1 Ectopic parathyroid glands Medrano et al. successfully performed VATS ectopic parathyroidectomy in 7 patients. He pointed out that preoperative ectopic parathyroid glands must be precisely located according to CT, MRI, thallium-Tc isotope scan, etc. VATS should be performed based on this localization with direct resection rather than extensive exploration.
3.2.2 Thymic disease VATS thymectomy is less invasive than open or transthoracotomy and has a wider field of view than a transcervical incision. There are more reports confirming that VATS is feasible for complete thymectomy, but only in patients with thymic cysts, some severe myasthenia gravis, and stage I thymoma. Those with known malignancy or evidence of localized exenteration of the thymoma must undergo open thoracotomy or sternotomy. When localized extravasation or signs of malignancy are found during VATS, to minimize the risk of incomplete thymoma resection, intermediate thoracotomy or sternotomy is performed 3.3 Middle mediastinum
3.3.1 Bronchial cysts Due to the introduction of VATS technology, surgical resection of all adult asymptomatic bronchial cysts is now recommended by most, and minimally invasive surgery is preferred. Intraoperatively, the cyst should be removed as completely as possible, with fine needle aspiration and decompression to aid in the clamping and separation of the cyst. When the cyst wall is closely adherent to important mediastinal structures, part of the cystic bark can be left behind, but the mucosal layer must be destroyed by electrocautery and other means to reduce the recurrence rate.
For bronchial cysts with preoperative complications (rupture and infection) or CT showing tight adhesions with surrounding tissues, VATS is difficult to perform and standard open thoracotomy is preferable. VATS is safe and effective for bronchial cysts without obvious symptoms, complications and adhesions.
3.4 Posterior mediastinum
3.4.1 Neurogenic tumors Most posterior mediastinal tumors are of neurogenic origin, and malignant ones are rare in adults, for which surgery is the treatment of choice. It is now generally accepted that VATS is safe and effective for the removal of smaller, non-invasive neurogenic tumors of the posterior mediastinum. Contraindications include: tumor diameter >6 cm, intradural invasion, consideration of malignant lesions, and tumor location too high or too low (beyond the 1st-12th intercostal nerves.
Preoperative CT and MRI are routinely performed to exclude intradural invasion. This dumbbell-shaped tumor accounts for about 10% of cases and was once considered an absolute contraindication to VATS, requiring the cooperation of thoracic and neurosurgical surgeons to remove intradural and intrathoracic tumors in one stage.
3.4.2 Hyperhidrosis Hyperhidrosis of the palms or axillae is due to overproduction of sweat glands in the upper extremities. Conservative treatment for idiopathic hyperhidrosis is poor, and surgical excision or severance of the upper sympathetic chain is the best treatment. In 1954, Kux was the first to use conventional thoracoscopic sympathetic chain dissection for idiopathic hyperhidrosis, but some surgeons still insist on using non-thoracoscopic surgical methods.
Compared with conventional thoracoscopy, VATS has a wider field of view and its magnification-enhanced contrast feature helps to precisely cut the T2 to T5 ganglion fibers intraoperatively, avoiding damage to the T1 ganglion (stellate ganglion), and also separates some of the pleural adhesions and identifies and cuts the variant nerve (Kuntz nerve) thus reducing complications and recurrence rates. Regardless of the procedure, compensatory hyperhidrosis is the most common postoperative complication, up to 50-80%. The mechanism is unclear, but most patients have mild, self-limiting symptoms.
3.4.3 Pain in advanced pancreatic cancer Severe refractory abdominal pain due to advanced intra-abdominal tumors of the pancreas, liver and bile and chronic pancreatitis is transmitted through the abdominal plexus, abdominal ganglia and visceral size nerves. The effect of blocking the abdominal plexus with alcohol injection is transient, and VATS can be performed via intrathoracic visceral neurotomy. To reduce pancreatic secretion, additional vagotomy has been suggested 3.4.4 Esophageal disease
Heller’s esophageal myotomy was the classical procedure for the treatment of cardia, but later balloon dilatation has gradually replaced the former with the advantages of less trauma and faster recovery. However, long-term follow-up results showed that the long-term symptom relief rate of the former was significantly higher than that of the latter, with 95% and 65%, respectively.
In recent years, VATS has been introduced for the treatment of achalasia of the cardia, but more and more clinical practice has shown that laparoscopy has gradually replaced VATS as the ideal method for the treatment of achalasia of the cardia because of the good exposure of the esophageal fissure and lower esophagus and the lack of single-lung ventilation and access to the chest cavity required by VATS. However, VATS should be used in a small number of patients, such as those with esophageal smooth muscle tumors, esophageal diverticula, or when a long esophageal muscle layer needs to be incised.
3.4.4.2 Benign esophageal tumors For benign esophageal tumors such as smooth muscle tumors and esophageal cysts, the standard surgical treatment is open thoracotomy, but it is usually used only for patients whose diagnosis is not very clear or whose lesions are gradually increasing in size. The introduction of VATS allows for the removal of early lesions with few complications and satisfactory surgical results, and VATS is most effective for smooth muscle tumors of 2-5 cm in diameter.
Contraindications include those who have had a recent mucosal biopsy (especially within 2 weeks) or with other serious esophageal disease. Esophageal mucosal tears are a more common complication, mostly due to large tumors, heavy adhesions, or improper intraoperative handling. Intraoperative cooperation of esophagoscopy is useful for localization of tumors less than 2 cm in diameter and examination of mucosal integrity.
3.4.4.3 Esophageal cancer Initially, VATS was used to free the intrathoracic esophagus in combination with a standard dissection and neck incision to complete the resection anastomosis of the esophagus. depaula et al. were the first to report complete laparoscopic resection of esophageal cancer in 1996. Recently, Luketich et al. reported 77 cases of esophageal resection using combined television thoracoscopic and laparoscopic techniques on this basis.
This included 52 cases of esophageal cancer, 19 cases of Barrett’s esophagus with highly abnormal hyperplasia (carcinoma in situ), and 6 cases of esophageal esophageal lesions. Most of the patients had been staged preoperatively by combined TV thoracoscopy and laparoscopy and EUS examination to exclude distant metastases and to estimate that the lesions could be resected. The average intraoperative lymph node clearance was 16, the average operative time was 7.5 h, the 30-day perioperative mortality rate was 0%, and the complications were 27%. With a mean follow-up of 20 months, all of the benign lesion group (6 cases) survived.
The survival rate of the tumor group (71 cases) was 81%. Luketich concluded that combined TV thoraco-laparoscopic resection is technically safe and feasible, and it has a rapid recovery and short hospital stay compared with conventional surgery, but it requires high technical and instrumentation requirements, and further study results are still needed to confirm whether it is superior to conventional surgery.
4.Thoracic trauma
4.1 Diaphragmatic injury The total incidence of diaphragmatic injury in thoracic and abdominal trauma is about 3%, it often lacks typical clinical signs, and combined injuries often mask the presence of diaphragmatic rupture, with a misdiagnosis rate of more than 30%. This can lead to chronic diaphragmatic hernia, where the contents of the hernia can become entrapped or strangulated, and even cause death. Clinically, the presence of diaphragmatic injury can be clarified for those who undergo emergency open-heart or dissection, and further investigations are needed for those who do not require emergency surgery but suspect diaphragmatic injury.
VATS is not only accurate and safe in diagnosing diaphragmatic injury, but also compared with laparoscopy, it has a wide field of view and can clearly explore one side, especially the right side of the diaphragm lesion, and can simultaneously diagnose and treat concomitant injuries in the ipsilateral thorax, avoiding the risk of tension pneumothorax or peritoneal adhesions caused by laparoscopy due to pneumoperitoneum, and MRI is feasible for those who are contraindicated for VATS. Once the diagnosis of traumatic diaphragmatic rupture is clear, surgery should be performed immediately. Small diaphragmatic ruptures can be repaired by VATS, while large diaphragmatic tears or associated abdominal organ injuries should be operated simultaneously by caesarean section.
4.2 Coagulative hemothorax Traumatic hemothorax or hemopneumothorax will develop into residual hemothorax in about 4-10% of patients even after closed drainage. It is defined as a pleural effusion that persists after 72h of chest tube drainage, regardless of infection. A small amount of fluid can be automatically absorbed by the body, while a medium amount of fluid (>500ml) or more may become infected and form a pus chest or further transform into a fibrothorax. Traditional management methods include additional chest tube placement or early open chest surgery.
VATS allows rapid and complete drainage of blood and fibrous clots, identification and treatment of persistent bleeding sites, exploration and treatment of other intra-thoracic injuries, and selection of the best location for tube drainage under direct vision.
4.3 Hemorrhage and pneumothorax Progressive bleeding, persistent air leak and intra-thoracic foreign body due to thoracic trauma are indications for surgical investigation. In cases that meet these criteria and are stable, VATS has proven to be a safe and effective approach. Bleeding or air leaks can usually be controlled by electrocautery, sutures, titanium clips, or suture cutters. If intraoperative diagnosis of large vessel injury or main bronchial dissection is made, immediate conversion to open thoracotomy is often required.
5.Outlook
VATS has been developed from simple intrathoracic operation to difficult surgery such as lung and esophageal tumor resection in only ten years, and it has become an inseparable part of modern general thoracic surgery because of its great superiority and huge development potential in clinical application. However, at the same time, we should also clearly understand that this is the result of strict patient selection, clear indications for surgery and proficiency in conventional surgery and VATS techniques.
Only if we continue to strictly follow this principle, we have reason to believe that VATS will have a brighter future with the progress of science and the continuous improvement of surgical techniques.