Funnel chest (pectus excavatum, PE) accounts for more than 90% of pediatric thoracic skeletal deformities, with an incidence of 0.1% to 0.3% and a male to female ratio of 4:1. The disease is congenital and often familial, and is autosomal dominant. Most have no obvious symptoms. Common symptoms.
1. susceptibility to upper respiratory tract infections and restricted mobility.
2. Panic, shortness of breath and dyspnea during activity. Special signs: thoracic deformity, mild hunchback and convex abdomen.
The traditional method of correction of funnel chest applies the sternal elevation method and its modification founded by Ravitch in 1949. The disadvantages are large incision, trauma, bleeding and slow recovery. It is easy to damage the pleura, lung and pericardium, and there are many postoperative complications. Postoperative care is complicated and the recurrence rate is high.
In 1987, Dr. Nuss proposed to place a special plate directly behind the sternum through the anterior chest wall to support the sternum and elevate it according to the principle that the thorax can be reshaped by external forces, thus realizing a minimally invasive surgical method without removing the rib cartilage and osteotomy of the sternum. The results of 42 cases were reported for the first time in the American Journal of Pediatric Surgery in 1998. With the advantages of minimal trauma and good results, the procedure soon spread in Europe and the United States and became popular worldwide, and was considered a cosmetic surgery.
In 2006, our hospital reported the initial and intermediate results of Nuss surgery with imported and domestic steel plates to correct funnel chest, and the excellent rate reached 98%; Nuss surgery with personalized steel plate bending technique for asymmetric funnel chest can also achieve better orthopedic results. In China, Nuss surgery is accepted by more and more parents and surgeons.
I. Indications for Nuss surgery
Most children with funnel chest do not have obvious clinical symptoms at the time of surgery, and it is traditionally believed that the purpose of surgery is to correct chest wall depression. Recent studies have found that funnel chest mainly affects the cardiovascular function of the child, rather than the pulmonary ventilation as traditionally thought. If symmetrical funnel chest is not corrected in childhood, it may become asymmetrical after 12 years of age; early surgical correction of funnel chest can not only improve the appearance of chest wall deformity and correct the inferiority complex of the child, but also eliminate the impact on respiratory and circulatory function at an early stage and avoid the aggravation of symptoms of cardiopulmonary impairment in adulthood. In children older than 12 years old, the extension and flexibility of the chest wall are reduced, which will prolong the operation time, increase bleeding and complications; while in younger children, the growth of the chest may be damaged, leading to serious pulmonary dysfunction and complications such as asphyxial thoracic dysplasia, which may cause irreversible consequences although the incidence is low.
In view of the fact that Nuss surgery is still traumatic to the child, it is currently considered appropriate to operate at the age of 3-12 years, with 6-12 years being the best. Most scholars consider the indications for Nuss surgery as.
1, age >3 years, with the optimal age being 6-12 years.
2. moderate or severe symmetrical funnel chest deformity with Haller index >3.2 on CT.
3, pulmonary function tests suggest restrictive or obstructive airway pathology, susceptibility to upper respiratory tract infections, reduced tolerance for strenuous activity, shortness of breath when running or climbing stairs.
4, heart pressure displacement, electrocardiogram shows myocardial damage.
5, other surgical methods failed.
Nuss surgery is contraindicated for adolescents who have a serious psychological burden and require correction of their appearance.
II. Nuss surgery steps and points
It can be divided into pleural access and extrapleural access Nuss surgery. The basic steps of pleural access Nuss surgery are
1.Pre-operative preparation
Chest X-ray and CT scan to understand the degree of deformity pulmonary function, electrocardiogram and echocardiogram to understand cardiopulmonary function and control respiratory tract infection. Intraoperative in supine position, chest padded, both upper limbs abducted 90 ° routine disinfection, laying of towels.
2.Select the plate of suitable length
Mark the lowest point of the thoracic depression and make a horizontal line, and select the appropriate rib gap position at the funnel crest. The distance between the mid-axillary line on both sides via the lowest point of the thoracic depression minus 1-2 cm is the alternative brace length, and adjust the steel plate so that the curvature is consistent with the preset lifting height. The position of the fixator should be as close as possible to the position of the plate into the chest. For asymmetric funnel chest, obliquely placed steel plates or irregular steel plate support can be used.
3.Incision
A transverse or longitudinal incision between the bilateral anterior axillary line and the mid-axillary line, 2-2.5 cm long, is made to cut the subcutaneous skin tissue, free the muscle flap to the edge of the ipsilateral depression (pre-selected plate exit and entry point), and a 5 mm trocar is stabbed into the chest cavity between the ribs of the right side incision to establish an artificial pneumothorax (5-6 mmHg) and place the thoracoscope. Intraoperatively, 0 degree or 30 degree lumpectomy is used. Generally, the right side of the thoracic cavity has more space, and the trocar is placed on the right side; attention is paid to avoid Trocar damage to the diaphragm and liver. Some foreign scholars recommend placing Trocar in the intercostal space above the plate placement point.
4.Establishing a tunnel behind the sternum
Under thoracoscopic surveillance, the Lorenz penetrator is passed through the chest wall at the pre-selected rib space, and carefully passes through the posterior sternal longitudinal septum to the contralateral chest wall penetration point, reaching the contralateral incision. The penetrator is withdrawn and a thick band is introduced. Take care not to damage the pericardium.
5.Introduce the plate
Fix the thick band firmly with the supporting plate, pull the thick band, and under the surveillance of the thoracoscope, the supporting plate is bowed backward through the tunnel.
6.Adjust the plate
Adjust the steel plate so that it is in complete agreement with the curvature of the chest wall. The flipper rotates the supporting steel plate 180° so that it bows upward and is supported behind the sternum, and the plate is fixed on one or both ends of the fixator.
7.Fixing the plate
The lung was puffed with the assistance of anesthesiologist (PEEP 4~6cmH2O), the chest gas was removed, and the lung was seen to be fully inflated under direct vision; the Trocar poke hole was sutured closed; the plate and fixator were tied and fixed with nylon thread or wire thread, and then the ends of the plate and fixator were fixed with chest wall muscle and fascia wrapping suture. To prevent displacement, some scholars use stainless steel wire to bind the plate to the rib, or use the 3-point fixation method.
8.Closing the incision
The subcutaneous tissue is sutured, and the skin is sutured intradermally.
In recent years, some scholars have proposed to perform the surgery via extrapleural approach. The basic principle of the operation is the same as that of the pleural cavity approach. The difference lies in the introduction of the guide through the right incision via the extrapleural cavity: the tip of the guide is first placed in the intercostal space at the highest point of the rib cage through the submuscular tunnel of the right incision under direct vision, and the guide is gently released from the intercostal muscle; the tip of the extrapleural guide can be shown through the translucent pleura under the thoracoscope, and the guide is bluntly separated from the extrapleural space toward the lowest point of the sternum, with the point of action of the guide close to the rib cage to avoid piercing the pleura, so that the guide The point of action of the guide is close to the rib cage to avoid puncturing the pleura, so that the guide is free outside the pleura immediately after reaching the lowest point of the sternum, and then continue to separate against the sternum to the contralateral intercostal space. The rest of the procedure is the same as the pleural cavity approach. Thus, the Nuss plate is placed outside the pleural cavity. The advantages are.
1, reduced possibility of pericardial injury.
2, the pleural cavity is intact, avoiding the stimulation of the pleura and lung by the steel plate, avoiding compression of the wall pleura by the steel plate, and reducing painful stimulation
3, maintaining the integrity of the pleural cavity, which is more physiological, less traumatic and reduces the chance of pleural cavity infection.
4.The steel plate is supported by the extra pleural tunnel tissue, which is not easy to displace, slide and rotate.
III. Complications of Nuss surgery and prevention matters
Complications after Nuss surgery are reported in the literature as high as 21-67%, among which the more serious complications include: cardiac penetrating injury, hemopneumothorax, pericardial effusion or pericarditis, infection, metal allergy, displacement of fixator and plate, etc. The differences reported in the literature for different complications were 2.9%-59.6% for pneumothorax, 1.7%-56.7% for pleural effusion, and 2.8%-29.9% for displacement of the supporting plates, respectively. Postoperative pneumothorax, pleural effusion, pulmonary atelectasis and pain had little effect on prognosis and only prolonged the hospital stay. The occurrence of pericardial effusion is associated with pericardial injury during surgery and should be highly alert for early diagnosis and effective hormonal therapy. Rarer complications include cardiac and liver injury, support plate allergy, and secondary scoliosis. Secondary scoliosis is mostly due to postoperative pain. Wound infection rates range from 1-6.8%, with Staphylococcus aureus as the predominant pathogen. Most cases can be controlled with drainage and antibiotic treatment without early plate removal.
Displacement of the plate is the most common cause of reoperation, including left and right movement, up and down rotation, and backward plunging; the incidence was reported to be 15.7% in early foreign literature, and reduced to 5.4% after the application of fixators. It is important to choose the right length of plate, fixator and fixation method with chest wall. Generally, the length of the plate should be 1-2 cm shorter than the distance between the mid-axillary line on both sides, because the path of plate placement is shorter than the actual measured distance; the center of the plate should be at the lowest point of the sternal recess, and the position of the inlet and outlet should be in the middle of the high point of the rib projection, when the plate is most stable. If the exit or entrance of the pleural cavity is too far to the outside, the plate will be stripped of the intercostal muscles when it is turned, resulting in instability of the plate and causing chronic pain after surgery. The shape of the plate should have a 2-4 cm flat area in the middle and slight curvature on both sides, if the flat area in the middle is too long stability is poor. In children >12 years old or with body shape close to adult, 2 plates should be placed due to stiffness of chest wall, which can reduce the support strength of each plate and reduce the occurrence of plate displacement. Some foreign scholars have taken some improvement measures to reduce the incidence of plate displacement, such as Hebra’s “3-point method” to fix the plate, and Uemura’s stainless steel wire to tie the plate directly to the ribs to prevent the displacement of the supporting plate.
IV. Treatment after Nuss surgery.
1.Pain management
Postoperative pain is the most common and should be actively treated, otherwise it may lead to acquired scoliosis. Commonly used methods include: intravenous analgesic pumps, oral analgesic tablets, analgesic suppositories, etc. More scholars advocate continuous epidural anesthesia for analgesia; intraoperative intercostal nerve block anesthesia can also be performed.
2.Strengthen respiratory management
Nebulized inhalation, expectoration and other treatments can be performed, and children are encouraged to blow up balloons to prevent pneumonia and pulmonary atelectasis.
3.Anti-infection treatment.
4.Some patients may have symptoms such as abdominal distension, abdominal pain or constipation, which may be related to the extrusion of intercostal nerve by the plate or the use of analgesics, and can be treated symptomatically after excluding abdominal surgical conditions.
5.Postoperatively, patients should try to keep chest up and shoulders horizontal posture, do not bend over to carry heavy objects within 2 months, avoid strenuous and confrontational sports within 3 months; children of low age should be supervised to prevent accidental injury from dislocating or breaking the steel plate.
6. Remove the steel plate 2-4 years after surgery, and avoid MRI examination before removal.
Large case reports at home and abroad show that the short-term satisfaction rate after Nuss surgery for symmetric funnel chest is close to that of traditional open surgery, and the recent satisfaction rates of children and parents are good 93% and good 96%, respectively. Although the complications of Nuss surgery are higher than those of the modified Ravitch procedure, the difference is not statistically significant; and is mainly due to early inexperience. The study showed that 70% of the surgical complications occurred in the first 9 months of the procedure; 90% of the complications occurred in the first 25 cases; and the overall complication rate was 29.4% in the initial 50 cases performed and decreased to 12% in the later years, with only 1.2% of the plates displaced. It shows that the correction results and complication rate of the Nuss procedure are closely related to the experience of the surgeon.