NEONATAL SURGERY - 1976

2. SPECIAL SECTIONS

8. Malformations of Individual Organs and Systems

Pulmonary Atelectasis

Atelectasis refers to the incomplete expansion of lung tissue. In newborns, a distinction is made between "congenital" or primary atelectasis, caused by delayed lung expansion after birth, and "acquired" or secondary atelectasis, which occurs when previously air-containing areas of the lung collapse (Potter, 1971).

Pathogenesis. With the onset of breathing, the Lungs expand gradually. After the first breaths, expanded alveoli account for an average of 2%. By the end of the 1st hour, the number of air-filled alveoli reaches 40%. However, even 10 to 12 hours after birth, a significant number of airless areas remain in the lungs. These atelectases are considered physiological. Blood flow through the pulmonary vessels and capillaries, as well as the restructuring of the lesser Circulation following umbilical cord clamping, plays a crucial role in the expansion of the Respiratory system of the lung (I. K. Esipova, O. Ya. Kaufman, 1968).

The delayed expansion of the lungs and The Development of "congenital" atelectasis—which would be more correctly termed "anectasis" (D. S. Lindenbraten, L. D. Lindenbraten, 1957)—may be caused by underdevelopment of the respiratory Divisions of the lung, pulmonary artery hypoplasia, weakness of the Respiratory Muscles and pliability of the osteocartilaginous framework of the chest wall in premature infants, or depression of the respiratory center resulting from trauma or ischemia of the Central Nervous system during labor, or maternal abuse of sedatives in the immediate prepartum period.

Secondary ("acquired") atelectasis, which is most commonly obstructive, results from the aspiration of Amniotic Fluid and remnants of amniotic membranes, or from The formation of hyaline membranes within the lumen of the alveoli and alveolar ducts. In recent years, many researchers have associated the development of atelectasis with a surface-active substance—surfactant¹. This lipoprotein substance forms a thin film at the interface between the air and the liquid lining the alveolar surface. When the alveolar lumen is distended, the film creates a surface tension of 40 — 50 dyn/cm², which tends to reduce the volume of the stretched alveoli and promotes lung deflation during expiration. With slight distension of the alveolar wall, the surface tension of the film decreases to 5 — 10 dyn/cm² (Avery, 1965). Due to this, the alveoli can easily be re-expanded during inspiration. This reduction in surface tension occurs under the action of an inhibitor, the destruction or congenital deficiency of which leads to alveolar collapse and the development of pulmonary atelectasis. A deficiency of surface-active substances is constantly found in the lungs of fetuses and premature infants. The development of "hyaline membrane disease," which is observed almost exclusively in premature newborns, is also associated with altered surfactant properties.

¹ From English surface activity.

In rare cases, airway obstruction occurs when they are compressed externally by an aberrant artery, cyst, or tumor. Compression of the lung by intestinal loops in a diaphragmatic hernia typically causes the appearance of atelectatic areas. Inflammatory processes in the lungs can also be a cause of atelectasis. Bronchopneumonia at an early age is frequently accompanied by focal and sometimes total atelectasis due to the accumulation of exudate in the airway lumen.

Clinical presentation. Primary atelectasis resulting from respiratory center depression manifests as profound cyanosis in the absence of dyspnea. Respiratory movements are weak and superficial. The respiratory rhythm may be irregular, exhibiting a wavelike character with gradual intensification and weakening up to complete cessation of breathing. Respiratory sounds are transmitted poorly or are entirely inaudible. When one of the lungs is underdeveloped, respiratory failure may be compensated.

In obstructive atelectasis, patients make vigorous breathing efforts. The primary manifestation of this pathology is marked dyspnea, characterized by deep inspiratory retraction of the Sternum, jugular notch, and intercostal spaces. The pliability of the newborn's chest cage causes the pleural cavity to lack adequate negative pressure, even with contractions of the Diaphragm that are sufficient in force. This hinders lung expansion and sustains the atelectasis. Cyanosis may be pronounced, but is more often intermittent. The described picture may be observed immediately after birth, but sometimes occurs after several hours of normal breathing (in neonatal hyaline membrane disease). Physical findings include diminished respiratory sounds and the presence of moist rales of various calibers, occasionally crepitant. Respiration may have a stridorous tone. Foamy discharge from the Mouth is noted, sometimes tinged with blood.

The most characteristic presentation is unilateral atelectasis: lagging of one half of the chest during breathing, dullness to Percussion on the side of the atelectasis, and a hyperresonant (drum-like) tone over the contralateral lung, in which compensatory (vicarious) emphysema typically develops. The Mediastinum is shifted toward the affected side. Auscultation over the affected lung or a limited area thereof reveals diminished breath sounds.

The severity of the condition and the degree of respiratory failure depend on the volume of the atelectasis. As studies show (Minkowski, 1953), asphyxia is observed when less than 1/6 of the lungs is expanded. In other cases, the volume of expanded alveoli is sufficient to maintain gas exchange. The reduction in the respiratory surface area of the lungs is accompanied by hypoxemia and carbon dioxide retention. The resulting acidosis is mixed in nature, caused by hypercapnia and the accumulation of under-oxidized metabolites due to oxygen deficiency. Infection frequently develops in atelectatic lungs, which exacerbates the severity of the patients' condition and worsens the prognosis. Atelectasis often causes delayed postnatal lung development. According to observations by E. V. Ryzhkov (1959, 1960), neonatal atelectasis underlies many "congenital" bronchiectases in children.

Radiological presentation. Total atelectasis appears radiologically as diffuse opacification of both lungs. The chest cage is cone-shaped, the Ribs are lowered, the intercostal spaces are narrowed, and the diaphragm is elevated. Against the Background of opacification, translucent stripes of the main and lobar Bronchi filled with air may be revealed. According to D. S. Lindenbraten (1957), this sign makes it possible to distinguish anectasis from obstructive atelectasis and pulmonary agenesis.

In lobar and segmental atelectasis, a localized homogeneous opacity with clear margins is determined, resembling the picture of lobar or segmental Pneumonia. Neighboring PARTS OF THE lung appear emphysematous, which can be a cause of diagnostic error—they may be interpreted as congenital lobar emphysema (I. K. Esipova, M. N. Stepanova, and L. M. Roshal, 1965). Unlike the latter, the affected half of the chest in atelectasis appears reduced in size, and the mediastinum occupies a median position or is pulled toward the atelectasis.

Disseminated multiple atelectasis is invariably accompanied by areas of emphysema. The lungs have a mottled appearance. Areas of opacification are surrounded by a zone of hyperlucency, and signs of interstitial emphysema in the form of focal air accumulations are frequently identified (Caffey, 1956). The latter sign is most commonly encountered after attempts at pressure lung expansion.

Treatment. In all cases, treatment begins with the aspiration of the Oral Cavity and Pharynx. For primary atelectasis associated with central nervous system damage, respiratory stimulants—analeptics (nikethamide, caffeine, cytiton, lobeline)—are used, along with controlled ventilation with a controlled pressure within the range of 15 — 20 mm H₂O. The filling of pulmonary capillaries with blood ("capillary erection") creates conditions for the expansion of the respiratory divisions of the lung (I. K. Esipova, O. Ya. Kaufman, 1968). In this regard, it is advisable to include medications that reduce resistance to pulmonary blood flow, such as aminophylline, in the therapy of congenital atelectasis. Klaus (1963) achieved a dramatic reduction in neonatal mortality by using intravenous administration of acetylcholine solution, which promotes vasodilation in the lesser circulation and enhances pulmonary blood flow. A positive effect is observed with the administration of cholinesterase inhibitors—neostigmine, galantamine—whose administration, In addition to acting on the pulmonary Vascular System, helps strengthen respiratory Muscle contractions. When there are marked retractions of the compliant areas of the chest wall, it is recommended to fix the sternum with a suture passed through the xiphoid process and pulled up using a rubber band to the top of the incubator (Benson, 1962). This technique facilitates lung expansion by stabilizing the chest cage. The entire force of the diaphragmatic muscle is thereby directed toward creating negative pressure in the pleural cavity and expanding the lung.

In obstructive atelectasis, the evacuation of tracheal and bronchial contents is facilitated by a high-humidity atmosphere (inhalations of sodium bicarbonate and Proteolytic Enzymes—chemopsin, Chymotrypsin, Ribonuclease). When these measures are ineffective, therapeutic bronchoscopy under anesthesia is successfully employed (I. G. Klimkovich, 1963).

Hypoxia is reduced by the inhalation of a 30 — 40% humidified oxygen mixture, and in cases of large bronchus obstruction, a helium-oxygen mixture (V. A. Mikhelson et al., 1972).

To correct acidosis, in addition to improving pulmonary ventilation, sodium bicarbonate solution or Buffer solutions (THAM, trisamine) are used under the control of blood acid-base balance studies. Broad-spectrum Antibiotics are prescribed for the Prevention of bacterial infection.

Pulmonary Malformations

Various degrees of pulmonary underdevelopment can occur in newborns—ranging from hypoplasia of the terminal bronchioles of a single segment to the complete absence of both lungs. According to various authors, the frequency of pulmonary malformations varies, accounting for 1.5 to 40% of all pediatric surgical respiratory diseases. The relative rarity of pulmonary anomalies detected in newborns is explained by the difficulties of their Diagnosis.

At the same time, alongside true congenital pathology arising before birth, There is a significant number of diseases resulting from deviations in the normal Development of Respiratory Organs in the early postnatal period, morphologically characterized by the same features. Naturally, these "postnatal malformations" cannot be detected in newborns.

Embryogenesis OF THE lungs and the formation of its major malformations are schematically depicted in Fig. 38.

Class="center">Fig. 38. Lung embryogenesis and main variants of developmental defects.

The primary laryngotracheal diverticulum appears during the 4th week of development (a). Initially, it is round in shape and communicates with the ventrocaudal part of the pharynx. Two thickenings, referred to as lung buds, appear at the distal end of the diverticulum. The entodermal buds, which constitute the primordium of the parenchymal part of the bronchi and lungs, begin their development within the surrounding mass of mesenchyme. This mesenchyme forms the stroma of the pulmonary lobules, cartilaginous plates, smooth muscle, and Connective Tissue. The stages of bronchial tree formation are shown in figures a through e. By the beginning of the 2nd month of development, the formation of three lobes of the right lung and two lobes of the left lung is already predetermined (g).

Growth arrest at any of the presented stages leads to the formation of a specific defect. Cessation of laryngotracheal diverticulum growth results in bilateral lung aplasia—a condition incompatible with life from the moment placental circulation ceases. Growth arrest of one of the two primary lung buds culminates in unilateral lung agenesis (e). Pulmonary hypoplasia (g) may be caused by embryogenesis disorders at any of the subsequent (b, c, d) stages. It is believed that cystic pulmonary hypoplasia (h) is most commonly the consequence of development arrest in the branching phase of the bronchial tree beyond the 4th to 5th order branches. The formation of solitary cysts (i) and lobar emphysema (k) also results from malformation of the lung tissue. Unlike the previous conditions, these may not manifest immediately after birth, as a certain (variable in duration) period of pulmonary respiration is required for their clinical presentation.

Tracheal Agenesis

This is a rare developmental defect in which the Trachea ends blindly without communicating with the bronchi. The latter typically open into the lumen of the Esophagus. Diagnosis is performed using tracheobronchoscopy. Patients with tracheal agenesis are practically nonviable, although they may breathe through the esophagus for some time. Fonkalsrud, Martelle, and Maloney (1963), and subsequently Altman, Randolph, and Shearin (1972), attempted surgical correction of the defect. The esophagus was transected in the neck, and both ends were brought out to the Skin. A tracheostomy cannula was inserted into the distal segment. In the first case, a thoracotomy was performed, the esophagus was transected distal to the fistula, and both of its ends were closed tightly with sutures. The child lived for 1 1/2 months after surgery. In the second case, The Stomach was transected at its cardia through a laparotomy incision. The patient died a few hours postoperatively.

Congenital Tracheal Stenoses

Tracheal narrowing may be true or caused by external compression of its lumen.

True congenital tracheal stenoses are typically associated with wall hypoplasia, although there is a view regarding The Role of intrauterine inflammation in The Emergence of this developmental defect. According to I. G. Klimkovich et al. (1969), tracheal narrowings are rarely diagnosed at an early age, despite clinical manifestations being present from the first days of life. This is explained by the rarity of the pathology, which is little known to the general pediatric community.

Clinical presentation. The symptomatology of congenital tracheal stenoses depends on the degree of luminal narrowing. In severe cases, wheezing stridor and dyspnea with retraction of the intercostal spaces, suprasternal notch, and even the sternum immediately draw attention after the child's birth. These phenomena intensify when the child is agitated and diminish at rest. In cases of less pronounced stenosis, clinical signs are detected primarily during respiratory episodes. Any inflammation accompanied by laryngotracheitis runs a severe course in such patients and frequently leads to severe bouts of asphyxia. Diagnosis is accomplished via bronchoscopy; however, the true dimensions and extent of the narrowing can only be revealed through radiographic examination. Stenosis is clearly visible on tomograms. In individual cases, tracheal contrast imaging—tracheography—may become necessary, which is safer to perform in such patients under general anesthesia guided by a bronchoscope (I. G. Klimkovich et al., 1970).

Treatment. In A number of cases, as the trachea grows, the relative degree of stenosis decreases. Therefore, all attempts at surgical correction are recommended to be undertaken no earlier than 5 to 6 years of age. Exceptions are patients with pronounced stenosis in whom surgery cannot be postponed due to respiratory failure and hypoxia. In all cases, Surgical treatment is preceded by a thorough examination of the child, as The Nature of the intervention depends on the level and extent of the narrowing. The simplest treatment method is tracheostomy, which allows for the postponement of radical defect correction, but is only feasible in high and localized stenoses. If the Nature of the pathology precludes tracheostomy, plastic surgery is employed, which is currently technically achievable (M. I. Perelman, 1972).

Tracheal Cysts

Paratracheal cysts (tracheocele), arising As a result of a disruption in the chondrogenetic phase of the trachea (Hollinger, 1956), are occasionally found in the tracheal region. In the event of underdevelopment of individual cartilaginous rings of the trachea, its mucous membrane may evaginate at the sites of the compromised cartilaginous framework. The further development of these evaginations and their transformation into paratracheal cysts occur during subsequent periods of embryogenesis. Such cysts can compress the tracheal lumen and impair breathing (Hardy, 1949). The diagnosis is established via bronchoscopy and radiological examination (Potts, 1950).

Another cause of tracheal cysts is anomalous tracheal branching. In these instances, a so-called tracheal bronchus branches off from the trachea above its bifurcation, frequently ending in a cystic dilatation.

Lung Agenesis

Bilateral lung agenesis is extremely rare. Infants are nonviable and perish shortly after umbilical cord clamping. Agenesis of one lung has been described by numerous authors and represents a developmental defect in which the trachea narrows and transitions into the bronchus of a solitary lung. The lung tissue, Blood Vessels, and bronchi on one side are completely absent.

Clinical presentation. The absence of one lung is usually compensated for by Hypertrophy of the contralateral lung, and at birth, infants sometimes do not differ from healthy ones. Among 4 clinic patients observed with lung agenesis and aplasia, the diagnosis was not established within the first months of life in any of them. Some degree of hypoxia is occasionally noted, but it is typically attributed to labor pathology.

Clinically, pulmonary underdevelopment manifests as chest Asymmetry and lagging of the affected side during respiration. The cardiac borders are shifted toward the agenesis, and when the process is right-sided, this usually leads physicians to suspect dextrocardia or other cardiac pathology. Breath sounds over the missing lung may be conducted due to the healthy lung herniating far beyond the bounds of the corresponding hemithorax.

Signs of respiratory failure may be absent in such patients until the child contracts pneumonia. Pneumonia in a solitary lung runs an extremely severe course and frequently ends fatally. Concurrently, individual patients survive to advanced age.

On a plain chest radiograph, opacification and a reduction in the size of one of the pulmonary fields draw attention. Experience shows that atelectasis of the lung, emphysema on the healthy side, and even Empyema of the pleural cavity are most frequently diagnosed in these cases. Lung agenesis is characterized by high positioning of the diaphragmatic dome, narrowing of the intercostal spaces, and a sharp degree of mediastinal shift toward the opacification. Tracheobronchoscopy settles the diagnosis. Contrast examination of the bronchi is hazardous due to limited respiratory reserve and the potential for developing pneumonia in the sole lung. In lung agenesis and aplasia, it is generally unnecessary.

Treatment. This developmental defect requires no special treatment. An exception is patients with a long bronchial remnant in the form of a blind pouch, where mucus can accumulate, causing a picture of chronic suppurative lung disease. Resection of such a remnant at an older age relieves the patient of a persistent wet cough.

Hypoplasia of the Lung, Lobe, or Segment

This developmental defect differs from the preceding one in that a more or less underdeveloped lung bud, consisting of bronchi surrounded by alveolar tissue, departs from the trachea. Lobar, segmental, and smaller bronchi may be observed, which typically terminate in cystic cavities of various sizes. The volume of the Respiratory Portion is usually minimal, and it is functionally inadequate.

In individual cases, microscopic examination reveals club-like dilations of the distal bronchi, from which respiratory bronchioles and even direct alveoli originate. This picture resembles amphibian lungs and allows such patients to be classified into a group with temporary developmental arrest of the bronchial tree (I. K. Esipova, 1962).

Clinical presentation. The symptomatology of pulmonary hypoplasia in a newborn largely resembles that described above. As with lung agenesis, the majority of patients exhibit a shift in cardiac borders, a reduction in the size of one hemithorax, and asymmetry of respiratory excursions. Breath sounds may be diminished and have a bronchial tone. The presence of rales of varying pitches indicates The addition of an inflammatory process and is secondary in nature. In the neonatal period, infection is observed less frequently, and pulmonary hypoplasia may proceed almost asymptomatically. A wet cough with purulent sputum develops later. Recurrent pneumonia with a predominant localization on the affected side, during which the anomaly is discovered, constitutes one of the manifestations of the pathology.

On a plain chest radiograph, areas of radiolucency may be identified against a background opacification, corresponding to cystic cavities or hypoplastic lung tissue. Cysts are occasionally quite large, occupying the entire pleural cavity. Significant mediastinal shift and pulmonary opacification are typically absent in such cases. When numerous small cavities are present—a condition referred to as "bronchial diverticulosis"—the lung may even appear more emphysematous than a healthy one.

Differential diagnosis requires contrast studies. Indications for this are usually determined following direct visualization of the trachea via a bronchoscopy, which reveals a narrowed orifice of the main bronchus of the hypoplastic lung, frequently obstructed by mucus. In hypoplasia of the distal bronchi, the endoscopic appearance may be almost indistinguishable from normal. Bronchography—during which bilateral contrast administration should preferably be avoided—delineates the hypoplastic and dilated bronchi (Fig. 39). Part of the contrast agent may penetrate into the cystic cavities, producing the characteristic pattern of cystic hypoplasia or congenital polycystic lung disease.

Fig. 39. Bronchogram of a 4-month-old infant. The bronchoscope tube is in the left main bronchus. The cystically altered bronchi of the left lung are opacified with contrast medium. Diagnosis: hypoplasia of the left lung. Left-sided pulmonectomy. Recovery.

Hypoplasia of a lung lobe or segment is rarely diagnosed during the neonatal period. The primary manifestations of this pathology are a persistent moist cough and recurrent pneumonia. In rare cases, the hypoplastic area of the lung, existing in a state of atelectasis, is visible on a plain chest radiograph, but even this sign is more commonly observed in older children.

One potential complication of terminal bronchial hypoplasia is Spontaneous pneumothorax, the Etiology of which frequently remains unexplained in neonates. Isolated observations have demonstrated that a sharp increase in intrabronchial pressure resulting from coughing, crying, or straining can cause rupture of malformed pulmonary tissue, particularly when more or less large bronchial branches are located in the immediate vicinity of the pleural surface.

Treatment. Infected polycystic lung disease or cystic hypoplasia requires the resection of the pathological areas. However, these surgical Procedures are typically performed at the age of 1 ¹/₂ to 2 years or older. In rare cases involving persistent recurrent pneumonia or pulmonary rupture, surgical intervention may be indicated During the first months of life. It should be noted that neonates and infants tolerate total pneumonectomy poorly, and the outcomes of such operations in this age group are frequently unfavorable.

Particular attention should be drawn to cases of pulmonary hypoplasia associated with congenital diaphragmatic hernias. In such patients, the lung is reduced in size, underdeveloped, and often incapable of filling the vacated pleural cavity following diaphragmatic repair. This explains the prolonged persistence of air in the pleural cavity on the operative side. As studies by I. K. Esipova demonstrate, all pulmonary structures in such instances develop proportionally, experiencing only a temporary developmental delay due to continuous compression by abdominal viscera during the prenatal period. Following surgical correction of the defect, the lung develops rapidly and achieves full functional capacity.

Solitary Lung Cysts

Solitary lung cysts in neonates are less frequent than in older children and arise predominantly as a result of developmental Malformations of the lung.

Pathogenesis. According to Sauerbruch (1934), A. I. Abrikosov (1947), Spenser (1962), I. K. Esipova (1962), and others, the primary role in the pathogenesis of congenital cysts is played by bronchial hypoplasia, which, unlike polycystic disease, has a limited, localized character. Sante (1939) and V. R. Braitsev (1960) allow for the possibility of cystic bronchial dilation caused by fluid accumulation secondary to obstruction (such as a membrane) or detachment. Among other proposed causes are intrauterine inflammation, stretching of the embryonic pulmonary lymphatic clefts, and evagination of the tracheal and bronchial mucosa at sites of wall hypoplasia. Vascular anomalies are also assigned a specific role—namely, the cystic degeneration of lung tissue driven by elevated blood pressure resulting from a vascular communication between a pulmonary segment and the systemic circulation. In the latter scenario, an aberrant vessel originating from the thoracic or Abdominal Aorta is typically present. This developmental anomaly is known as "pulmonary sequestration" and demands meticulous attention during surgery, as ligation or division of the accessory vessel carries the risk of fatal Hemorrhage (Fig. 40).

Fig. 40. Features of the Blood supply to the embryonic pulmonary bud leading to the development of sequestration.

The potential for congenital lung cysts to develop is supported by autopsy findings of pulmonary cavities in fetuses and stillborn infants; however, the proportion of such findings is low. Potter (1952), drawing on extensive experience in the pathoanatomical examination of embryonic and neonatal lungs, identified cysts in only 2 cases. Caffey (1953) never encountered a lung cyst during the radiological examination of 5,000 neonates within the first 3 days of life. In older age groups, solitary cysts structurally resembling congenital ones are observed significantly more often. These facts led A. P. Kolesov (1950), Mayer and Rappoport (1952), and E. V. Ryzhkov (1959) to hypothesize that pulmonary cysts may arise as a result of developmental deviations from the normal pathway in the postnatal period under METABOLISM/18.html">The Influence of various factors. The latter include neonatal atelectasis, pneumonia, underdevelopment of elastic fibers in the walls of alveoli and bronchi, and their subsequent distension driven by elevated intrabronchial pressure (coughing, sneezing, check-valve bronchial obstruction, etc.). In older children, "acquired" lung cysts may form secondary to the epithelialization of abscesses, emphysematous bullae, or traumatic cavities. Pulmonary cysts are therefore of polyetiological origin.

Clinical Presentation. Based on their clinical course, lung cysts are classified into uncomplicated and complicated categories. The latter are further subdivided into cysts complicated by suppuration, a tension (valvular) mechanism, or wall rupture.

Uncomplicated cysts of the lung in neonates are diagnosed extremely rarely, as their clinical symptoms are sparse and routine screening radiography is not performed at this age. Occasionally, an air- or fluid-filled cavity is discovered incidentally on a radiograph taken for pneumonia or abdominal pathology. More frequently, cysts are detected only after the onset of complications.

Suppuration of a cyst. The pathways of infection in intrapulmonary cysts vary. Infection may penetrate the cyst via its draining bronchi, and hematogenous or lymphogenous routes cannot be excluded. Suppurated lung cysts in newborns and infants present with a pronounced clinical picture resembling necrotizing pneumonia. A persistent, nagging cough appears, general condition deteriorates, and dyspnea develops. Children become restless and irritable, refuse feeding, and lose weight. A number of patients exhibit dyspeptic disorders, such as altered stool consistency and vomiting. The vomitus frequently contains traces of purulent sputum, which young children typically swallow. A significant elevation in body Temperature is rare in neonates due to their diminished physiological reactivity. Physical examination reveals signs of purulent intoxication and hypoxia: pallor, icteric skin tones, cyanosis of the mucous membranes and the nasolabial triangle, depression of the fontanelles and eyeballs, loss of skin turgor, and other signs of dehydration. Premature infants rapidly develop sclerema, which serves as a poor prognostic indicator.

Physical examination allows the detection of signs of a pulmonary cavity only when it is significantly large or located superficially. In such instances, localized tympanites or an area of dullness to percussion is found. Auscultation reveals varying degrees of diminished breath sounds over the cyst area along with moist rales of various calibers.

Complication by a valvular mechanism. Unilateral check-valve obstruction of the bronchi draining the cyst most commonly occurs in children against the background of pneumonia and serves as the primary driver for the enlargement of intrapulmonary cysts. In newborns and infants, this complication is most frequently encountered and is accompanied by severe respiratory distress, permitting the description of a "decompensated" course of tension cysts in this age group. Beyond hypoxia caused by pulmonary compression, the severity of the patients' condition is explained by cardiovascular failure resulting from compression of the venae cavae due to mediastinal shift. The latter is particularly prone to displacement in neonates owing to the laxity of the connective tissue and the delicate structures anchoring the mediastinal organs.

The clinical picture in infants with tension lung cysts is dominated by symptoms of acute respiratory distress: pronounced dyspnea with retraction of the intercostal spaces, suprasternal notch, and epigastrium, alongside cyanosis. Groaning respiration, tachycardia, and congestive hepatomegaly are noted. Without timely intervention, these patients may succumb to asphyxia within hours of the complication's onset.

Physical examination reveals Displacement of the cardiac borders, tympanitic Resonance on the affected side, and dullness to percussion on the contralateral side. Breath sounds on the affected side are sharply diminished or absent entirely. Harsh breath sounds and rales of various calibers are auscultated over the contralateral lung.

Rupture of the cyst wall occurs upon a sharp rise in pressure within the cavity or inflammatory destruction of its capsule. A frequent trigger for this complication is the puncture of a cyst, especially one under tension. The symptoms of the ensuing pneumothorax or pyopneumothorax differ little from those described above, but their onset is typically more acute, accompanied by signs of pleuropulmonary Shock and severe agitation in the child. Respiratory distress is also more pronounced.

Occasionally, suppurated cysts undergo sudden evacuation into the bronchial tree, resulting in asphyxia. This complication is life-threatening exclusively in neonates and infants, as older children generally expectorate sputum independently. A severe coughing fit ensues, abundant sputum appears, and deep cyanosis develops. Massive aspiration of purulent material can cause the sudden death of a young child with a lung cyst.

Radiological Findings. The diagnosis of lung cysts in children is established primarily through radiography, with plain chest radiography and tomography being the Methods of choice. The Need for contrast studies in neonates arises extremely rarely.

Uncomplicated lung cysts present as a thin-walled air-filled cavity, occasionally multilocular. Some patients may present with fluid-filled cysts (Fig. 41). These appear as rounded opacities of uniform density with clear, smooth contours, standing out sharply against the background of the surrounding lung tissue.

Fig. 41. Chest X-rays.

a — air cyst of the left lung in a 2 ¹/₂-month-old infant; b — fluid-filled cyst of the right lung in a 1-month-old infant.

Children with infected cysts present with cavities of varying sizes containing fluid levels. The walls of an infected cyst appear thickened and coarser, and a perifocal reaction is frequently observed. The presentation resembles that of lung abscesses, but the inner contour of the cyst is usually smoother (Fig. 42).

Fig. 42. Chest X-ray of a 22-day-old infant. Diagnosis: infected cyst of the right lung.

In tension lung cysts, the X-ray reveals a marked hyperinflation of one pulmonary field and mediastinal shift to the opposite side. In addition, there is a mediastinal hernia and low standing of the diaphragmatic dome, while fluoroscopy shows restricted mobility of the diaphragm on the affected side (Fig. 43).

Fig. 43. Chest X-ray of a 14-day-old infant. Diagnosis: tension cyst of the right lung.

The radiological presentation of a cyst that has ruptured into the pleural cavity is characterized by symptoms of pneumothorax or pyopneumothorax, usually of the tension type. In multilocular cysts, their contours may be visible against the background of the collapsed lung and air in the pleural cavity (Fig. 44).

Fig. 44. Chest X-ray of a 1-month-old infant. Diagnosis: rupture of the right lung cyst wall. Pneumothorax.

Differential Diagnosis. Solitary lung cysts in newborns most frequently need to be differentiated from bullous cavities associated with staphylococcal pneumonia, as well as from large solitary lung abscesses. A single radiological examination makes it difficult to determine the exact nature of the cavity. Differential diagnosis is based on tracking the dynamics of the cavities, which, if of inflammatory origin, tend to decrease in size and spontaneously disappear within a few days or months. Lung cysts are characterized by greater constancy in size and shape.

Tension cysts in newborns must be differentiated from congenital lobar emphysema, pyothorax, pyopneumothorax, and diaphragmatic hernias, which, in cases of "asphyxial strangulation" (S. Ya. Doletsky), can mimic the picture of intrathoracic tension. Correct diagnosis is facilitated by identifying the contours of the tension cavity on the X-ray, which are sometimes better visualized in the lateral projection. Pneumothorax and pyopneumothorax are characterized by the shadow of a collapsed lung, whereas in lobar emphysema, a thinned pulmonary pattern can be traced against the hyperinflated background. The Radiological Diagnosis of diaphragmatic hernia is described in the relevant section and is facilitated by the characteristic Clinical symptoms of these conditions.

Treatment. Uncomplicated cysts. The presence of an intrapulmonary cyst (unless it significantly compromises the respiratory surface area) has little direct impact on the child's health. The risk lies in complications whose time of onset is difficult to predict. This necessitates treating uncomplicated lung cysts as potentially dangerous conditions and justifies their radical excision. However, due to the challenges of differential diagnosis and the severity of the postoperative period in newborns and infants, surgical treatment for uncomplicated cysts is generally recommended after the child reaches 1 to 1 ¹/₂ years of age.

   Complicated cysts. The development of complications significantly alters the therapeutic strategy. Upon discovering a purulent cavity on chest X-rays, treatment should begin with efforts to eliminate the inflammatory process. If conservative therapy is effective (intravenous, intramuscular, and aerosol antibiotics; boosting specific and nonspecific Immunity via blood transfusions, including direct ones, plasma transfusions, gamma-globulin injections, etc.), radical surgery is performed after establishing a definitive diagnosis of a lung cyst, i.e., 10 to 12 months later. A lack of treatment response, and particularly progressive clinical deterioration accompanied by other complications, are indications for surgery despite ongoing suppuration. In newborns with tension lung cysts, radical surgery must be performed urgently. Cavity drainage only temporarily improves the infant's condition and is therefore appropriate only when it is impossible to take the patient straight to the operating table. Prolonged drainage almost inevitably leads to Pleural Empyema. Puncture of a tension cyst is frequently complicated by wall rupture and the development of tension pneumothorax or pyopneumothorax, and is therefore contraindicated. Excision of a tension cyst immediately restores normal conditions for the respiratory and circulatory systems. The patients' condition often improves while still on the operating table. A similar approach is adopted in newborns with a ruptured lung cyst wall resulting in pneumothorax.

Modern Anesthesiology and Intensive Care make it possible to perform intrathoracic operations even in infants during their first days of life. The risks associated with these procedures are lower than the danger of pleural infection and Sepsis development. The Scope of intervention depends on the Location and volume of the cystically altered lung tissue. In young children, lung resection is preferably performed within anatomical boundaries—a lobe or a segment—with careful sealing of the remaining lung tissue. Due to the delicacy of the Tissues, manual closure of the ROOT elements is preferred, as existing surgical staplers are too bulky for infants of this age. The outcomes of lung surgery in infants during their first months of life largely depend on preventing infections of the pleural cavity and soft Tissues of the chest wall, delicate surgical technique, and meticulous replacement of blood loss. The severity of the postoperative period in these patients and the frequency of postoperative complications, among which pulmonary atelectasis and postoperative pleural empyema rank first, require close attention and properly organized nursing care.

Lobar Emphysema

Progressive emphysematous enlargement of a lung lobe is most frequently encountered in newborns and infants in their first months of life¹. Lobar emphysema in a newborn was first described by Kountz and Alexander (1943). A significant number of case studies have since been published, including in domestic literature.

¹ The condition is known under various names: congenital lobar emphysema, localized hypertrophic pulmonary emphysema, progressive neonatal emphysema, etc.

Pathogenesis. Lobar emphysema represents progressive distension of a lung segment, indicating the presence of a check-valve mechanism within the bronchi of the affected lobe. The causes of partial valvular bronchial obstruction vary. These include hypoplasia and sometimes complete absence of Cartilage tissue in the bronchi, causing bronchial collapse during expiration; hypertrophy or edema of the bronchial mucosa; localized bronchospasm; and external compression of the bronchial lumen by enlarged Lymph Nodes, a tumor, or an aberrant blood vessel. Valvular bronchial obstruction is detected in approximately half of patients with lobar emphysema. Mayer and Rappoport (1952) suggested that in addition to bronchial obstruction, the hyperinflation of the lung lobe is caused by underdeveloped elastic tissue in the alveolar walls and reduced contractility during expiration.

Clinical Presentation. The typical clinical manifestations of lobar emphysema include progressive dyspnea with retractions of compliant chest wall areas, cyanosis, and labored, sometimes wheezing respiration. Symptoms usually appear shortly after birth or during the first month of life. Infants are admitted in critical condition, driven by hypoxia and Heart Failure associated with the compression of the venae cavae due to mediastinal shift. Physical examination reveals enlargement of one hemithorax and its lag during respiration. Percussion reveals a tympanic note over one lung and a shift of the cardiac borders to the opposite side. Occasionally, the patient's condition stabilizes, which has led to the Classification of cases with compensated and decompensated respiratory failure (S. A. Stepanov, Yu. A. Vodolazov, 1963).

Radiological findings. Plain chest radiography reveals an emphysematously enlarged lung lobe, most commonly the upper lobe, which displaces adjacent areas and herniates into the contralateral hemithorax. A more or less pronounced mediastinal shift is observed in all patients. The pulmonary vascular markings on the affected side are significantly diminished, yet remain quite distinct, which helps differentiate this condition from a tension cyst or pneumothorax (Fig. 45). In most cases, contrast-enhanced studies are unnecessary. In complex diagnostic scenarios where the specific emphysematous lobe is uncertain, tomography is recommended, supplemented by pulmonary angiography if facilities permit. Bronchography in these patients may exacerbate hypoxia and promote the development of pneumonia.

Fig. 45. Chest radiograph of a 25-day-old infant. Diagnosis: congenital lobar emphysema of the left upper lobe.

Differential diagnosis. A frequent pitfall in this malformation is the misinterpretation of radiological findings, leading to an erroneous diagnosis of pneumothorax or a tension lung cyst, followed by unintended puncture of the emphysematous lobe or thoracentesis. Not only are these procedures ineffective, but they can also cause lung laceration and pleural infection. In other cases, the collapsed lung tissue is frequently mistaken for atelectasis, and

the emphysema is erroneously considered compensatory. Consequently, attempts at bronchial aspiration or bronchoscopy are often performed, which can further aggravate hyperinflation and hemodynamic instability.

Treatment. Surgical intervention remains the only definitive treatment for lobar emphysema. In patients with decompensated forms of the disease, surgery is performed on an emergency basis immediately upon diagnosis. Thoracotomy and resection of the emphysematous lung areas are performed under endotracheal anesthesia with controlled ventilation (S. Ya. Doletsky et al., 1970). Upon induction of anesthesia, the infant's condition may deteriorate due to positive pressure inflation of the affected lobe, causing further enlargement. Given this risk, performing thoracotomy under spontaneous breathing until the chest is opened—transitioning to Artificial ventilation only thereafter—is recommended (Mushin, 1963). The emphysematous lobe appears pale pink, enlarged, and fails to deflate during respiration. The demarcation from healthy lung tissue is usually well-defined, confirming the diagnosis.

In cases of compensated respiratory failure, surgery may be postponed until a later age. In isolated cases, the signs of tension gradually subsided and the radiographic picture normalized. However, the majority of these children continued to exhibit low body weight, a frail constitution, and a high susceptibility to respiratory infections even at an older age. Therefore, surgical intervention is considered indicated in compensated forms of the anomaly as well.