[Visa-assisted Thoracic Surgery] 4K Ultra-High Definition Spontaneous Pneumothorax Surgery

The pleural cavity is a closed cavity without air, surrounded by the visceral pleura and the parietal pleura. The visceral pleura is close to the lungs, and the parietal pleura is close to the chest wall. There is one pleural cavity on each side, which is not ventilated to each other. There is only a small amount of serous fluid inside, which reduces friction during breathing and acts as a lubricant. The negative pressure in the pleural cavity is lower than the atmospheric pressure. Pneumothorax refers to the rupture of the pleura, which allows air to enter the pleural cavity and cause air accumulation. The direct consequence of air accumulation in the pleural cavity is compression of the lungs, causing the lungs to be unable to "work" normally.

Under normal circumstances, there is no gas in the pleural cavity. There are two types of gas according to the causes:

1. Primary spontaneous pneumothorax: It is caused by the sudden spontaneous rupture of lung tissue and visceral pleura, resulting in accumulation of air in the chest cavity. It is more "favorable" to young and middle-aged men with thin and tall bodies. This is mainly because thin and tall boys grow faster during development, and their alveolar elastic fibers are poorly developed. The alveolar elasticity is relatively poor, and they are prone to rupture. Thin and tall boys should pay attention to controlling the intensity when doing physical exercise and strenuous activities. If chest pain and difficulty breathing occur after coughing violently or exerting too much force, they should be alert to the possibility of spontaneous pneumothorax. Especially if spontaneous pneumothorax has already occurred once, the possibility of it happening again is still relatively high, so they should go to the hospital for medical treatment in time.

2. Secondary spontaneous pneumothorax: Pneumothorax caused by bronchial and lung diseases, such as tuberculosis, chronic obstructive pulmonary disease, emphysema, pneumoconiosis, etc.; pneumothorax can occur when there are no proper protective measures in aviation or diving operations, when a high-pressure environment is suddenly entered into a low-pressure environment, or when the ventilation pressure of the ventilator is too high.

Clinical manifestations

According to the severity, pneumothorax can be divided into:

1. Small pneumothorax (lung collapse within 30%): the patient has no obvious symptoms of respiratory and circulatory dysfunction.

2. Moderate pneumothorax (lung collapse 30% to 50%): there may be symptoms of chest tightness, chest pain, and shortness of breath after activity, but most young people only have chest tightness.

3. Large pneumothorax (lung collapse more than 50%): the chest cavity on the affected side is full; respiratory movement is weakened or disappeared, percussion tympanic sound, the patient has obvious symptoms of dyspnea and irritability, and cyanosis or even shock in severe cases.

We must diagnose and treat it quickly and correctly, otherwise it will cause lung atrophy and mediastinal compression and displacement, acute progressive respiratory and circulatory failure, and even death.

What are the treatments for spontaneous pneumothorax?

1. Symptomatic treatment: Strictly rest in bed, give sedatives, analgesics and other drugs as appropriate, pay attention to monitoring the condition, high-concentration oxygen inhalation can accelerate the absorption of gas in the chest cavity, and pay attention to the treatment of underlying lung diseases.

2. Moderate or large pneumothorax: can be cured by non-surgical treatments such as thoracentesis and closed chest drainage.

3. Surgical treatment: For patients with recurrent spontaneous pneumothorax, continuous air leakage in pneumothorax, and obvious bullae, surgical treatment should be given. Currently, 4k ultra-high-definition thoracoscopic surgery is the main method, and the commonly used surgical method is bullae resection + pleurodesis. This type of surgery has high safety and success rate, definite efficacy, and low postoperative recurrence rate.

4. Diagnosis:

1. Chest X-ray

Chest X-ray is the quickest and most reliable diagnostic tool. Bullae may resemble pneumothorax. However, the separation between lung tissue and air, which is usually convex in air, is concave in pneumothorax.

2. CT scan

CT scan should not be considered a routine diagnostic step but rather an optional tool to differentiate an airway from a pneumothorax. It is particularly useful in detecting contralateral bullae.

The general purpose has 3 goals:

1. Reexpansion of the lung: can only be done with chest tube drainage followed by aspiration therapy over several days with a negative pressure of about -20 cm H2O.

2. Leak repair: usually requires surgery, including suturing, suturing or adhesion of parenchymal leaks.

3. Prevention of recurrence: involves different techniques, the goal of which is to obliterate the pleural space by creating adhesions between the visceral pleura and the chest wall. This pleurodesis can be performed surgically (abrasion, pleurectomy), thermally (cautery, laser) or pharmacologically (instillation of antibiotics, talc, blood into the pleural space).

Conditions for VATS

Primary spontaneous pneumothorax: Whether video-assisted thoracoscopic surgery (VATS) is the first for primary spontaneous pneumothorax is under debate. The observed reduction in recurrence after VATS favors surgery. The cost (anesthesia, surgery, length of hospital stay) and the fact that simple drainage treats 50% of patients are detrimental to VATS.

After 10 years of experience with VATS, we believe that the technique is safe for a skilled thoracoscopic group (Hurtgen et al., 1996). Thoracoscopy allows for extensive surgery and is generally faster than thoracotomy. Adhesions, such as along the phrenic nerves or along the subclavian vessels, may require conversion to thoracotomy.

Secondary pneumothorax: The same prerequisites as for VATS are required. VATS can be performed by skilled surgeons. Those with less experience in VATS prefer VATS for secondary pneumothorax, especially when emphysema is present and the lung tissue is fragile. In these patients, the underlying obstructive lung disease must first be treated. Conversion to open thoracotomy cannot be ruled out in all cases.

Clinical manifestations

Indications

All cases of first recurrence of primary pneumothorax;

All cases of recurrence of secondary pneumothorax, as long as the surgeon has sufficient experience in VATS, the patient can receive split-valve ventilation.

Relative contraindications:

Postoperative recurrence of primary pneumothorax,

Previous history of ipsilateral pleural disease.

Anesthesia and Ventilation

All elective thoracoscopic procedures are performed under general anesthesia with a double-lumen tube for individual ventilation of the lung lobes.

With proper positioning of the endotracheal tube, pre-existing pneumothorax is deflated at the beginning of the procedure by passive pressure compensation between the external air and the pleural space, thus freeing the surgical site. If the lung is not deflated completely, endobronchial suction or bronchodilators can be given. Intrapleural gas insufflation is not necessary. As an alternative to double-lumen intubation, individual bronchial blockers with bronchoscopic positioning can be used for single-lung ventilation.

Partial inflation of the lung is important during the intervention to detect any bullous disease on the surface of the collapsed lung.

Operating room setup

General anesthesia;

Double-lumen endobronchial tube;

Lateral position (for standard posterolateral thoracotomy);

Horizontal placement of the ipsilateral arm to maintain extrathoracic working space for instruments.

Team

1. The surgeon stands in front of the patient.

2. The assistant is next to the surgeon.

3. The scrub nurse is placed next to the surgeon.

4. The anesthesiologist is placed at the patient's head

Equipment

1. Thoracoscopic equipment

2. Anesthesia unit

3. Operating table

4. Instrument table

Trocar puncture

Three-hole method usually required:

Optical needle: paravertebral, maximum distance from the anterior trocar;

Instrument trocar: third and ninth intercostal space at the anterior axillary line.

The trocar size should be appropriate for the diameter of the thoracoscope (10 mm or 7 mm) and the instrument being used. We recommend using a 7 mm thoracoscope because the 7 mm trocar is less traumatic to the paraspinal space.

Some surgeons prefer to make only 2 incisions and insert 2 instruments through one larger trocar. This technique may be adequate for simple intrathoracic maneuvers such as wedge resections. It is not suitable for difficult intrathoracic maneuvers because of the disadvantage of having 2 instruments on the same trocar that may obstruct each other.

Surgical Instruments

The solid chest wall greatly limits the maneuverability of instruments within the thoracic space. Therefore, greater requirements are placed on thoracic instruments than on tools used in standard laparoscopic surgery. At angles greater than 45°, strong friction within the cannula impedes instrument movement. More freedom of movement within the thorax can be achieved with angled or curved instruments and expands the intrathoracic working space to the chest dome and diaphragm.

Flexible cannulas without valves are necessary.

Other instruments

High frequency electrosurgical unit

Monopolar and bipolar cutting and coagulation tips or endoscopic scissors are well suited for thoracoscopic pneumothorax. Water irrigation during bulla cauterization can prevent its carbonization and thus avoid iatrogenic gas leakage.

Nd:YAG laser

In thoracoscopic surgery, thermal Nd:YAG lasers have the advantage of being versatile compared to Nd lasers, offering a versatile application including cyst coagulation hemostasis or bullectomy.

Argon ion beam

1. High frequency electrode

2. Argon flow

3. Tissue

The argon beam is particularly useful for hemostasis of extensive effusion areas after pleurectomy. The occurrence of pleurodesis is not easy due to the application of the beam to the parietal pleura. However, large coagulation areas on the pleura do not seem to be advantageous if HF-argon pleurodesis is performed (interruption of the vessels may reduce the fibrin supply). Therefore, it is recommended to coagulate only streaks of the pleura, as this ensures the expression of fibrin in the pleural cavity.

The application of the argon beam in the pleural cavity is safe if pressure compensation between the pleural cavity and the outside air is guaranteed by an open trocar.

Endoscopic staplers

The endoscopic staplers used are specially designed for thoracoscopic resection of lung parenchyma. They ensure safe closure of tissue along the resection. There are four sizes of endoscopic staplers (30/35/45/60 mm). The 60 mm stapler, due to its larger size, does not always provide free movement within the thorax, especially in the chest cavity. The new flexible staplers do not compensate for this disadvantage.

Examination

The first indispensable surgical step is a thorough lysis of the adhesions. Only in this way can a complete examination be performed, ensuring that the dorsal aspect of the lung, the mediastinum and the diaphragm are included. During the examination, gentle air insufflation helps to make the collapse of the lung surface grossly visible. For example, invisible bullae on the parenchymal base of adhesions can usually be clearly identified as the cause of pneumothorax and must be removed. They are often found as a result of previous pleurodesis or chest drainage. They are less vascular and are less significant in terms of recurrence than the above adhesions. They must be dissected to allow a thorough examination and to avoid the presence of some effusions.

Excision of bullae

A single bulla with a small parenchymal base was excised using 2 inner rings combined with additional sutures to prevent them from sliding during lung inflation. The ligation can be visually controlled when the lung is re-inflated at the end of the procedure.

Bullae

Bulises with extensive parenchymal base or bullous bullae with larger resection areas require endoscopic staplers.

Lung tissue can be easily guided to an intraparenchymal clamp, which must be inserted opposite the stapler. Guide the stapler both medially and laterally, the position of the needle receiving the stapler must be very low, as far back as possible. When using only 2 trocars, the stapler and clamp work parallel to each other, making the insertion of the parenchyma between the jaws of the stapler more difficult.

Wedge resection

If there is no bleb or air leak, the approach of choice is apical wedge resection combined with partial pleurectomy.

Alternative techniques

As an alternative to bullectomy, laser or bipolar electrocautery has been shown to be particularly effective, especially in patients with multiple subpleural bullae. Cauterization of the bullae wall during water lavage helps prevent postoperative air leaks and can be charred.

Pleurodesis

Repair of actual air leaks after additional pleurodesis can reduce the risk of recurrence by stabilizing the lung and chest wall. This prevents the infiltration of air from the lung into the pleural space if weakness of the lung parenchyma subsequently occurs.

The pathophysiological principle of adhesions of the lung wall to the chest wall is the secretion of autologous fibrin from the chest wall into the pleural space. Different technical solutions have been devised for this purpose (Hurtgen et al., 1996; Van den Brande and Staelens, 1989; Wakabayashi, 1989; Inderbitzi et al., 1993).

Pleurectomy (partial)

Partial or total pleurectomy is considered the safest technique for pleurodesis. The parietal pleura can be very finely separated from the thoracic fascia within an avascular layer with reduced field of view. To start the pleurectomy, a digital detachment of the pleura can be performed before the insertion of the instrument cannula into the extrapleural space. Thoracoscopy The thoracoscopic approach allows controlled blunt dissection with different instruments. The pleurectomy is performed between the first and fifth ribs, aided by the internal thoracic artery and down the paravertebral spine along the sympathetic nerves.

Pleurodesis

Mechanical pleurodesis

In mechanical pleurodesis (pleural abrasion), we roughen the pleura with dissecting swabs until petechiae appear.

Thermal pleurodesis

For thermal pleurodesis, electrocautery as well as argon beam techniques or laser can be used. The goal is to induce thermal injury to the parietal pleura, which then causes fibrin secretion.

Talc pleurodesis

Talc has been used for decades for chemical pleurodesis with high efficacy. It causes tight adhesions between the parietal and visceral pleura, making the procedure difficult. Therefore, its use in young patients is controversial. When talc (approximately 5 g) is applied, it should be distributed as a thin layer on the lung or parietal pleura using a sprayer.

End of procedure

Reinflation under visual control;

Chest tubes: Usually 2 chest tubes (Ch 28) are placed through the axillary incision and under visual control. At least one chest tube should terminate at the chest dome to achieve complete reinflation under suction at -20 cm H2O;

Trocar wound closure.

Conversion to thoracotomy

Conversion to thoracotomy is not a complication in itself. Intraoperative conversion may be necessary when endoscopic techniques cannot achieve the same results as open surgery, such as when wide resection or extensive suturing is required or when there is concern that some injuries may be overlooked or palpated.

Postoperative period

chest tube

When there is no longer any air leak, suctioning is stopped and the procedure is complication-free. The chest tube can be removed 2 to 4 days after surgery, with chest x-ray showing complete lung reexpansion and no pleural effusion. The approach to handling chest drains varies from hospital to hospital, depending on the surgeon's experience.

The intermediate postoperative drainage time for idiopathic pneumothorax is 4 days after VATS surgery and 6.5 days after thoracotomy. However, for secondary pneumothorax, the difference between thoracotomy and thoracoscopic surgery was not significant. In these cases, the longer drainage period is related not only to the lack of access, but also to the prolonged air leak caused by the emphysematous lung parenchyma.

Analgesics

Reduced postoperative pain and shortened drainage period are the main quality criteria of minimally invasive means. In our protocol, patients receive analgesics regularly during drainage. Initial oral analgesics after surgery may be sufficient. However, IV therapy or epidural catheters may be more painful. It is important to eliminate pain in order to mobilize the patient immediately after surgery. In some patients, analgesics may be required for several weeks after surgery.

Postoperative course

In more than 80% of patients, lung function returns to normal values, for forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) 6 weeks after surgery. In the remaining patients, moderate restrictive lung function with FEV1 values of about 75% of normal can be found.

In our own experience, the overall recurrence rate after VATS pneumothorax treatment ranges from 3% to 8%, which is similar to the data in the literature (Mouroux et al., 1996).

Complications

 Death

The mortality rate of VATS pneumothorax in patients with primary spontaneous pneumothorax should be zero. Patients with secondary pneumothorax are usually elderly patients with severe emphysema and chronic obstructive pulmonary disease. Therefore, postoperative mortality may occur depending on the severity of the underlying disease.

Bleeding

Severe bleeding from the intrathoracic intercostal arteries is rare but possible. It can be controlled by VATS or by conversion, depending on the surgeon's experience. Diffuse postoperative bleeding should be considered more frequently than in patients following surgery without pleurodesis (Naunheim et al., 1995).

Trocar injury

Trocar injury can be avoided by dissecting the trocar channel with scissors under digital control and using only blunt-tipped trocars.

The overall rate of complications can be estimated at 5% to 8% and is no higher than that of thoracotomy.

Conclusions

The recurrence rate after VATS is comparable to that after conventional thoracic surgery. Important advantages of VATS include accelerated recovery and less surgical trauma.

Experience has shown that 4K ultra-high-definition thoracoscopy provides a better understanding of the thoracic cavity, especially in the upper and lower parts of the chest, compared with open surgery. The magnification effect of the thoracoscope allows for more precise separation of the pleura from the intrathoracic fascia (Naunheim et al., 1995).

However, extensive experience is required to reduce the complication rate below that of thoracotomy. For example, postoperative bleeding is often caused by video miscalculation of chest wall hemostasis after pleurectomy. Compared with thoracotomy, video thoracoscopy is more difficult to inspect the total lung surface, especially during intraoperative ventilation when checking for air leaks or bullae.