I. General: Pediatric funnel chest 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 etiology is unclear. 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. Wuhan Union Medical College Hospital Pediatric Surgery Department Mao Yongzhong Air Force General Hospital Thoracic Surgery Department Zhu Yanjun 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, American Nuss
Dr. Nuss proposed to place a special plate directly behind the sternum through the anterior chest wall to support the sternum and elevate it, thus realizing a minimally invasive surgical method without removing the rib cartilage and osteotomy of the sternum. It is considered as a kind of 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, with an excellent rate of 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. 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 cardiopulmonary impairment in adulthood. In children older than 12 years of age, 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 have 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 believe that the indications for Nuss surgery are: 1. age >3 years, best age 6-12 years. 2. moderate or severe symmetrical funnel chest deformity, CT
Pulmonary function tests suggest restrictive or obstructive airway pathology, susceptibility to upper respiratory tract infections, reduced tolerance for strenuous activity, and reduced tolerance to strenuous activity.
4. The heart is displaced by pressure and the electrocardiogram shows myocardial damage.
5. adolescents who have failed other surgical methods. 6. adolescents with severe psychological burden who require cosmetic correction. contraindications to Nuss surgery are: 1. age < 2 years; 2. Haller index < 3.0
3. Severe asymmetric funnel chest and very severe funnel chest with limited depression. Nuss surgery steps and points: it can be divided into pleural access and extrapleural access Nuss surgery. (A) The basic steps of Nuss surgery by pleural cavity approach: 1. Preoperative preparation
The procedure is based on 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 supine position with chest padding and both upper limbs abducted at 90° Routine disinfection and towel laying. 2.
Select a plate of appropriate 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 the plate is adjusted 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, the plate can be placed diagonally or supported by irregular plates. 3. incision: transverse or longitudinal incision between bilateral anterior axillary line and mid-axillary line, 2-2.5 cm long. cut the skin subcutaneous tissue, free the muscle flap to the edge of the ipsilateral depression (pre-selected plate exit and entry point), 5 mm intercostal incision on the right side
The trocar is stabbed into the chest cavity, an artificial pneumothorax (5-6 mmHg) is established, and a thoracoscope is placed. 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 the Trocar between the ribs above the plate insertion point.4. Posterior sternal tunneling: Under thoracoscopic surveillance, the Lorenz penetrator is passed through the chest wall at the preselected rib space and carefully crosses the posterior sternal longitudinal septum to the contralateral chest wall penetration point, reaching the contralateral incision. The penetrator is withdrawn and the 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 pass the supporting plate through the tunnel posteriorly in an arch shape under the surveillance of the thoracoscope. 6. Adjust the plate: Adjust the plate so that it is perfectly aligned with the curvature of the chest wall. The rotator rotates the supporting plate 180° so that it is bowed upward and supported behind the sternum, and the plate is fixed on one or both ends of the fixator. 7. Fixing the plate: The anesthesiologist assists in puffing the lung (PEEP 4-6 cmH2O), removing the chest gas, and seeing the lung fully inflated under direct vision; the Trocar poke hole is sutured closed; the plate and fixator are tied with nylon or steel wire, and then the chest wall muscle and fascia are used to fix the plate. The ends of the plate and the fixator were fixed with embedded sutures. To prevent displacement, some scholars use stainless steel wire to bind the plate to the ribs or use the 3-point fixation method.8. Closure of the incision: subcutaneous tissue is sutured and the skin is sutured intradermally. (B) Extrapleural approach to Nuss surgery.
In recent years, some scholars have proposed to perform 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 puncturing 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. the possibility of pericardial injury is reduced; 2. the pleural cavity is intact, avoiding the stimulation of the pleura and lung by the steel plate, avoiding the compression of the wall pleura by the steel plate, and reducing the painful stimulation; 3. the integrity of the pleural cavity is maintained, which is more physiological, less traumatic, and reduces the chance of pleural infection; 4. the steel plate is supported by the extrapleural tunnel tissue, which is less prone to displacement, sliding, and rotation. Complications and prevention of Nuss surgery: Complications after Nuss surgery are reported in the literature to be 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. There was a large variation in the different complications reported in the literature, ranging from 2.9%-59.6% for pneumothorax, 1.7%-56.7% for pleural effusion, and 2.8%-29.9% for support plate displacement. Postoperative pneumothorax, pleural effusion, pulmonary atelectasis and pain had little prognostic impact 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-right movement, up-down rotation, and backward plunging; the incidence of 15.7% was reported in early foreign literature and reduced to 5.4% after the application of fixators. It is important to choose the appropriate length of plate, fixator, and fixation method to the 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 to 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 and chronic pain after surgery. The shape of the plate should be 2-4 cm flat in the middle and slightly curved on both sides, if the middle flat area 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, etc. Postoperative management of Nuss: 1.
Pain management: Postoperative pain is the most common and should be actively managed, otherwise there is a risk of acquired scoliosis. Commonly used methods include: intravenous analgesic pumps, oral analgesic tablets, analgesic suppositories, etc. More scholars advocate continuous epidural analgesia; intraoperative intercostal nerve block anesthesia can also be performed. 2.
Strengthen respiratory management: nebulized inhalation, expectoration and other treatments are feasible, 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 squeezing of the intercostal nerve by the plate or the use of analgesics, and can be treated symptomatically after excluding abdominal surgical conditions. 5.
After surgery, try to keep chest up and shoulders horizontal posture, do not bend and carry heavy objects within 2 months, avoid strenuous and confrontational sports within 3 months; strengthen supervision for younger children to prevent accidental injury from dislocation and fracture of the plate. 6. Remove the plate 2-4 years after surgery, 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 performing 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 Nuss surgery are closely related to the experience of the surgeon.