Placental weight, birth weight and fetal:placental weight ratio in dichorionic and monochorionic twin gestations in function of gestational age, cord insertion type and placental partition.

INTRODUCTION: We established reference values for placental weight, birth weight, and fetal:placental weight ratio (FPR) (a possible index of placental functional efficiency) in monochorionic and dichorionic twin gestations. METHODS: Placental weight, birth weight, and FPR in function of gestational age, cord insertion type and placental sharing were determined in 151 dye-injected diamniotic-monochorionic and 198 double-disc diamniotic-dichorionic twin placentas (25-39 weeks' gestation). RESULTS: As expected, FPR values increased with gestational age in both groups. Birth weights and placental weights of monochorionic twins >28 weeks' gestation were significantly lower than those of age-matched dichorionic twins. When stratified per placental weight, the birth weights and FPR values of monochorionic twins were overall lower than those of dichorionic twins within the same placental weight category. However, in the subset of monochorionic twins with small share in unevenly partitioned placentas, birth weights and FPR values per placental weight were similar to those of dichorionic twins, and significantly higher than those of monochorionic twins with larger share or even placental sharing. Cord insertion type did not correlate with birth weight or FPR values per placental weight in either twin type. DISCUSSION: Reference values were generated for placental weight, birth weight and FPR in monochorionic and double-disc dichorionic twins. The generally lower FPR per placental weight in monochorionic twins compared with dichorionic twins is suggestive of inherently lower placental functional efficiency in monochorionic gestations. The mechanisms and clinical implications of the apparent differential modulation of FPR/efficiency in monochorionic twins according to placental partitioning remain to be determined.

Correlation between cord insertion type and superficial choriovasculature in diamniotic-monochorionic twin placentas.

BACKGROUND: Non-central cord insertion has been associated with diminished chorionic vascular distribution in singleton placentas. The choriovascular correlates of peripheral cord insertion in diamniotic-monochorionic twin placentas remain undetermined. AIM: To study the association between type of cord insertion and choriovascular distribution of both twin territories in diamniotic-monochorionic twin placentas. DESIGN: A prospective cohort of 138 monochorionic placentas was examined at Women and Infants Hospital between 2009 and early 2011. Thirty-five cases (25%), including disrupted placentas, placentas from higher order multiples and placentas from pregnancies complicated by twin-to-twin transfusion syndrome, were excluded. The correlation between cord insertion type and superficial choriovascular distribution was studied in the remaining 103 dye-injected diamniotic-monochorionic placentas. Cord insertion was categorized as paracentral, marginal or velamentous. The choriovascular distribution of each individual twin territory was assessed by analysis of number and density (number per surface area) of perforating chorionic arteries (PCA). RESULTS: In contrast with singleton placentas, there was no correlation between cord insertion type and a twin's own choriovascular distribution in diamniotic-monochorionic placentas. However, a strong correlation was found between the choriovascular distribution of one twin and the cord insertion type of the opposite twin. For a twin with paracentral or marginal cord insertion, the PCA density was significantly higher if the co-twin had a velamentous cord insertion than if the co-twin had a paracentral cord insertion (P < 0.001 and P < 0.05, respectively). Similarly, the PCA density of a twin with velamentous cord insertion tended to be higher if the co-twin had a velamentous, rather than paracentral cord insertion (P = 0.09). CONCLUSIONS: This is the first study to suggest that in diamniotic-monochorionic twin gestations, the choriovascular architecture correlates with the cord insertion type of the co-twin. In general, velamentous cord insertion is associated with expanded choriovascular distribution in the opposite twin territory. Our observations may reflect novel manifestations of twin interdependence in monochorionic pregnancies.

Blast injuries--and the pivotal role of trauma surgeons.

An explosion is the sudden release of energy and its radial propagation through air, solid structures and living tissue. Treatment of blast injuries is complex and combines the principles of penetrating and blunt trauma, chemical or thermal burns and disaster and mass casualty management. Primary blast injuries are a direct result of the explosion itself. The sudden release of energy is translated into a shock wave that travels at supersonic speed (5000 metres/second). There is a sudden and short-lived rise in pressure, followed by a prolonged negative pressure, or vacuum, responsible for additional injury. The organs most at risk for primary blast injuries are the lungs, the ears and the gastrointestinal tract. The explosion also sets solid objects in motion; these act as projectiles, and can travel over far greater distances (secondary blast injuries), and their management is no different from penetrating or blunt trauma from other causes. The explosion may cause not only "projectiles," but the body itself to be displaced: These tertiary blast injuries include traumatic amputations and crush injuries following land mine explosions. Finally, quaternary blast injuries comprise other forms of associated trauma, such as burns, asphyxia or poisoning from release of noxious substances by the blast. These injuries can be particularly taxing for rescue teams because of their tendency to affect large amounts of patients and the risk they pose to the rescuers themselves. Individual management of the blast injury victim requires a multidisciplinary team; terrorist or wartime bombings also require expertise in disaster management and triage.

Placental characteristics of selective birth weight discordance in diamniotic-monochorionic twin gestations.

Up to 21% of diamniotic-monochorionic twin pregnancies are complicated by severe birth weight discordance in the absence of twin-to-twin transfusion syndrome, a serious condition termed 'selective' birth weight discordance. While its pathogenesis remains incompletely understood, the development of selective intertwin growth discordance, related to fetal growth restriction of one twin, is generally attributed to aberrant placental characteristics. The aim of this study was to characterize the placental markers of selective birth weight discordance, with special emphasis on the choriovascular architecture. A prospective cohort of 319 consecutive diamniotic/monochorionic twin placentas was examined at Women and Infants Hospital between 2001 and 2009. After exclusion of placentas from pregnancies complicated by twin-to-twin transfusion syndrome (TTTS), monoamniotic, multiple and disrupted placentas, 216 placentas (36 birth weight (BW)-discordant and 180 BW-concordant) formed the subject of this study. Following dye injection, the anatomic characteristics and choriovascular anastomotic patterns of BW-discordant and BW-concordant placentas were compared. The BW-discordant placentas showed significantly higher frequencies of velamentous cord insertion (22% versus 8%, P < 0.001) and uneven placental sharing (56% versus 19%, P < 0.0001) compared with BW-concordant placentas. The frequencies of intertwin AA, VV and AV anastomoses, the net number of AV anastomoses, and the net cross-sectional area of AV anastomoses were similar in both groups. There was no correlation between the frequency of velamentous cord insertion and degree of placental sharing or patterns of choriovascular anastomoses in either group. In conclusion, velamentous cord insertion and uneven placental sharing are the two major placental determinants of selective birth weight discordance in diamniotic-monochorionic twins. The role of the intertwin anastomoses, even when unbalanced, is likely negligible. Elucidation of the mechanisms whereby velamentous cord insertion affects fetal growth may lead to more focused and effective therapeutic strategies for twin and singleton pregnancies complicated by dysregulated fetal growth.

Placental markers of twin-to-twin transfusion syndrome in diamniotic-monochorionic twins: A morphometric analysis of deep artery-to-vein anastomoses.

Twin-to-twin transfusion syndrome (TTTS) is a multifactorial disorder that develops in 9-15% of diamniotic-monochorionic twin gestations. While the pathogenesis of TTTS remains poorly understood, unbalanced deep artery-to-vein (AV) anastomoses have traditionally been implicated in the gradual shift of blood from donor to recipient. The aim of this study was to define the placental markers of twin-to-twin transfusion syndrome, with special emphasis on the deep AV anastomoses. A prospective cohort of 284 consecutive diamniotic/monochorionic twin placentas was examined at Women and Infants Hospital between 2001 and 2008. Following exclusion of monoamniotic, multiple, disrupted and laser-treated placentas, 218 twin placentas (21 TTTS and 197 non-TTTS controls) formed the subject of this study. Placentas were injected with color-coded dyes. Anatomic characteristics and choriovascular anastomotic patterns of TTTS placentas were compared with non-TTTS controls. The TTTS placentas showed significantly higher frequencies of velamentous cord insertion, magistral vascular distribution patterns, uneven placental sharing, absence of AA anastomoses and presence of VV anastomoses. Deep AV anastomoses were identified in >or=95% of TTTS and non-TTTS placentas and were overall more abundant than previously reported. The total and net numbers of AV anastomoses were similar in both groups. However, the net cross-sectional area of AV anastomoses, which also takes into account the caliber of the vessels, was significantly smaller in TTTS placentas. There was no correlation between the direction of the AV imbalance and the twin donor/recipient status. In conclusion, TTTS has distinct placental characteristics, warranting their routine inclusion in the diamniotic-monochorionic placental pathology report. Our findings suggest imbalance of AV anastomoses is not required for the development for TTTS, although their presence, whether balanced or unbalanced, may contribute to the creation or perpetuation of the syndrome. Elucidation of the role of the various placental determinants in diamniotic-monochorionic twin gestations may lead to further refinement of therapeutic strategies.

Open and laparoscopic appendectomy are equally safe and acceptable in children.

BACKGROUND: The aim of this study was to evaluate prospectively whether laparoscopic (LA) and open appendectomy (OA) are equally safe and feasible in the treatment of pediatric appendicitis. METHODS: A total of 517 children with acute appendicitis were randomly assigned to undergo LA or OA appendectomy, based on the schedule of the attending surgeon on call. Patient age, sex, postoperative diagnosis, operating time, level of training of surgical resident, length of postoperative hospitalization, and minor and major postoperative complications were recorded. Chi-square analysis and the Student t-test were used for statistical analysis. RESULTS: In all, 376 OA and 141 LA were performed. The two groups were comparable in terms of patient demographics and the incidence of perforated appendicitis. The operative time was also similar (47.3 +/- 19.7 vs 49.9 +/- 12.9 min). The overall incidence of minor or major complications was 11.2% in the OA group and 9.9% in the LA group. CONCLUSION: Pediatric patients with appendicitis can safely be offered laparoscopic appendectomy without incurring a greater risk for complications. Nevertheless, a higher (but not significantly higher) abscess rate was found in patients with perforated appendicitis who underwent laparoscopy.

Experience with a multidisciplinary antenatal diagnosis and management model in fetal medicine.

BACKGROUND: Fetal medicine is a new and evolving specialty. Complex fetal conditions may require the multidisciplinary input of clinicians from many different specialties. METHODS: Referral of fetal patients was made to a multidisciplinary antenatal diagnosis and management (MADAM) board if more than one specialty (in addition to maternal-fetal medicine) needed to be intimately involved in the evaluation or care of the fetus; consultation would probably lead to alterations in fetal or perinatal management; or development or revision of management guidelines was anticipated. The case log of the MADAM conferences was reviewed retrospectively for number and type of fetal anomalies, and outcome of the presentation to the MADAM board. RESULTS: During a 5-year period, 1% of 25654 pregnant women who were evaluated required consultations with individual pediatric and pediatric surgical specialists. Of these, 114 patients were referred to one of 77 MADAM conferences for consensus recommendation. Of these 77 discussions, 32 (42%) led to an alteration in prenatal management, 14 (18%) led to co-ordination of postnatal management and 12 (16%) led to the establishment of a new treatment guideline, or the modification of an existing one. In all, perinatal management was altered in 75% of cases. CONCLUSION: The MADAM model functions as a forum for exchange of up-to-date scientific information, development of evidence-based treatment protocols and continuity of care through the pre-, peri- and postnatal periods.

Laparoscopic gastrostomy in infants and children.

Gastrostomy is a common procedure in children. Percutaneous endoscopic gastrostomy (PEG) is less traumatic than open surgery, but carries a higher risk in small children. We report our experience with laparoscopic gastrostomy, which appears to combine the advantages of the PEG and the safety of an open operation. Operative technique. An umbilical port (5 or 10 mm, depending on the patient's weight) and a left subcostal cannula (site of the future gastrostomy) are used. The stomach is pulled to the abdominal wall with two T-anchors, and the gastrostomy is performed using the Seldinger technique. A 17-Fr peel-away sheath is placed, through which a 5 mm endoscope is introduced to confirm its intragastric position. A 14-Fr balloon gastrostomy tube or button is then introduced. Results. Fifty-one children, aged 0 to 19 years (mean 4.4 +/- 6.4 years), underwent a total of 54 laparoscopic gastrostomies in a 42-month period. Thirty-three patients were younger than 2 years, and 22 weighed less than 5 kg. Thirty-three children had failure-to-thrive, 12 suffered from cerebral palsy and 8 from cystic fibrosis. Operative time was 33.6 +/- 14.3 minutes; in 18 cases, a concomitant Nissen fundoplication was performed (total operative time 76.5 +/- 58.7 minutes). In all cases, gastrostomy feedings were started the following day, and hospital stay in the gastrostomy-only group was 3.3 +/- 0.6 days. There were two (recognized) perforations of the back wall of the stomach, which were repaired laparoscopically, and two tube dislodgments, at 24 hours and at 4 months, requiring reoperation. Conclusions. Laparoscopy allows a quick and simple technique of gastrostomy placement under direct vision in even the smallest newborn and infant. It carries minimal operative risks and allows initiation of feedings within 24 hours.

Preoperative planning with magnetic resonance imaging and computerized volume rendering in twin-to-twin transfusion syndrome.

Our purpose was to illustrate the feasibility of preoperative planning with magnetic resonance imaging, 3-dimensional reconstruction, and volume-rendering techniques in twin-to-twin transfusion syndrome treated by endoscopic laser ablation of communicating vessels. After ultrasonographic determination of the syndrome and the indications for intervention, 2 patients with an anterior placenta underwent magnetic resonance imaging without the need for maternal or fetal sedation. Raw image data were downloaded into a desktop computer and manipulated with 3-dimensional reconstruction, volume rendering, and surgical navigation software. In both patients a virtual rendering of the fetuses, placenta, and uterus could be manipulated to expose all sides, demonstrate the location of the intertwin membrane, and plan the point of entry and curve of the endoscopic instruments. Preoperative planning and virtual surgical navigation in fetal surgery are now possible, as a result of shorter magnetic resonance imaging acquisition times and volume-rendering software. In this manner an entire virtual endoscopic fetal operation can be performed and fine-tuned before the actual procedure is to take place.

Effect of lung fluid composition on type II cellular activity after tracheal occlusion in the fetal lamb.

BACKGROUND/PURPOSE: Fetal tracheal occlusion (TO) causes accelerated lung growth. However, prolonged TO is associated with a decline in the type II cell number. Type II cell function after TO is unclear. Herein, the authors examine type II cell function after TO and the role of tracheal fluid. METHODS: Fetal lambs (term, 145 days) underwent TO at 122 days. Tracheal pressure was recorded daily. In one group of animals (TF; n = 6), lung fluid was aspirated, measured, and reinfused daily. In their respective twins, NS group, lung fluid was replaced milliliter per milliliter with normal saline (NS; n = 6). At death near term, lung weight was obtained, and tissues were processed for stereologic volumetry. Type II cells were quantitated using antisurfactant protein B immunohistochemistry. Surfactant protein B-mRNA expression was studied by Northern analysis. Wilcoxon signed rank test and single factor analysis of variance (ANOVA) were used for statistical analysis (P<.05 was significant). RESULTS: In both experimental groups, intratracheal pressure rose from 1.9+/-1.0 torr to 3.7 to 4.8 torr by day 1, and remained constant thereafter. Lung fluid volume increased from 11.9+/-4.2 on day 0 to 36.8+/-8.0 mL/kg in TF, and to 28.4+/-9.3 mL/kg in NS by day 1 (P<.05). At death, lung weight/body weight ratio was higher in TF (5.45% +/- 0.91%) than in NS (4.40% +/- 0. 67%) or control (3.83%+/-0.58%; P<.05). Type II numerical density was substantially reduced after TO: 57.7+/-12.8 x 10(6)/mL (TF) and 45.0 +/-25.9 x 10(6)/mL (NS), versus 82.3+/-13.6 x 10(6)/mL in controls. Ultrastructurally, remaining type II cells in TF were enlarged and engorged with lamellar bodies; in NS, they were smaller and contained fewer lamellar bodies. Surfactant protein B mRNA expression was significantly decreased in NS, but not in TF, compared with controls. CONCLUSIONS: Type II cell function as well as overall lung growth are stimulated by TO. Lung growth after TO is therefore not unavoidably detrimental to type II cells. After isobaric saline exchange of lung fluid, type II cell function is severely inhibited, confirming the role of tracheal fluid composition in type II stimulating type II cell function.

Fas ligand expression coincides with alveolar cell apoptosis in late-gestation fetal lung development.

Apoptosis plays a central role in the cellular remodeling of the developing lung. We determined the spatiotemporal patterns of the cell death regulators Fas and Fas ligand (FasL) during rabbit lung development and correlated their expression with pulmonary and type II cell apoptosis. Fetal rabbit lungs (25-31 days gestation) were assayed for apoptotic activity by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) and DNA size analysis. Fas and FasL expression were analyzed by RT-PCR, immunoblot, and immunohistochemistry. Type II cell apoptosis increased significantly on gestational day 28; the type II cell apoptotic index increased from 0.54 +/- 0.34% on gestational day 27 to 3.34 +/- 1.24% on day 28, P < 0.01 (ANOVA). This corresponded with the transition from the canalicular to the terminal sac stage of development. The day 28 rise in epithelial apoptosis was synchronous with a robust if transient 20-fold increase in FasL mRNA and a threefold increase in FasL protein levels. In contrast, Fas mRNA levels remained constant, suggestive of constitutive expression. Fas and FasL proteins were immunolocalized to alveolar type II cells and bronchiolar Clara cells. The correlation of this highly specific pattern of FasL expression with alveolar epithelial apoptosis and remodeling implicates the Fas/FasL system as a potentially important regulatory pathway in the control of postcanalicular alveolar cytodifferentiation.

Requirements for fetal surgery: the diaphragmatic hernia model.

Fetal surgery for congenital diaphragmatic hernia and other fetal conditions can only be considered if (1) the morbidity of antenatal intervention is acceptable, (2) the diagnosis of the condition can be made accurately, (3) the condition can be differentiated from other, non-surgical anomalies. In addition, (4) the natural evolution of the disease, if left untreated, should be predictable, and the condition should be lethal or severely debilitating, (5) there should not exist adequate postnatal treatment, and (6) the proposed in utero operation should be technically feasible. Open fetal surgery has proven too invasive to be justified for the treatment of diaphragmatic hernia, and progress in postnatal therapy (including ECMO) has dramatically improved the neonatal outcome in all but a severe subgroup of patients. Recently, advances in endoscopic fetal surgery (which appears to be less stressful for the fetus and the gravid uterus) and a new approach to accelerate fetal lung growth and maturation have renewed the feasibility of in utero intervention for diaphragmatic hernia.

Short-term tracheal occlusion corrects pulmonary vascular anomalies in the fetal lamb with diaphragmatic hernia.

BACKGROUND: Sustained fetal tracheal occlusion (TO) results in accelerated lung growth but causes severe type II cell depletion. Temporary TO fails to cause lung growth in a congenital diaphragmatic hernia (CDH) model but preserves type II cells and corrects pulmonary hypertension. Herein, we study the pulmonary vascular changes caused by temporary TO. METHODS: CDH was created in 12 fetal lambs (65-70 d; term, 145 days). In 6 lambs, the trachea was occluded for 2 weeks (CDH + TO; 108-122 d). Animals were killed at 136 days. The lungs were processed with elastin stains and anti-alpha-smooth muscle actin antibody. Partial or circumferential presence of inner and outer elastic lamina was used to determine muscularization of pulmonary arterioles. The percent of medial wall thickness was plotted against vessel diameter for each group. RESULTS: Lung weight/body weight was smaller in lambs with CDH (1. 35% +/- 0.56%) and CDH + TO (1.70% +/- 0.34%) than in control lambs (3.55% +/- 0.56%; P <.05, single-factor analysis of variance). The smallest muscularized vessel was 113 +/- 50 microm, and the largest nonmuscularized vessel was 138 +/- 49 microm in lambs with CDH, significantly different from control lambs (185 +/- 69 microm and 350 +/- 116 microm, respectively) and lambs with CDH + TO (185 +/- 97 microm and 245 +/- 100 microm, respectively; P <.05). In lambs with CDH, only 25% of vessels of less than 60 microm were nonmuscularized, compared with 81% in control lambs (P <.05) and 74% in lambs with CDH + TO.Conclusions. Temporary tracheal occlusion, from 108 to 122 days, corrects the abnormal muscularization of pulmonary arterioles seen in CDH. These morphometric findings parallel physiologic results at birth and further suggest that short-term occlusion, which preserves surfactant-producing type II pneumocytes without lung growth, may be sufficient to improve neonatal outcome of diaphragmatic hernia.

Late-gestation tracheal occlusion in the fetal lamb causes rapid lung growth with type II cell preservation.

BACKGROUND: Fetal tracheal occlusion (TO) results in varying degrees of lung growth. This study examines whether gestational age influences lung growth response following TO. MATERIALS AND METHODS: Fetal lambs (term = 145 days) underwent TO early (108 days, n = 6) or late (122 days, n = 6) in gestation. Aspirated lung fluid volume (LFV) and intratracheal pressure (ITP) were recorded daily. Two weeks after TO, the fetuses were sacrificed. Lung growth was assessed by lung weight and stereologic volumetry. Type II cellular density was assessed by computer-assisted morphometry using antisurfactant protein B antibody. RESULTS: After early TO, ITP remained below 2 mm Hg for all but one of the first 5 days. In late TO, ITP rose to 4.8 +/- 1.7 mm Hg by Day 1 and remained elevated. LFV remained lower after early than after late TO (P < 0.05) for 8 days. Thereafter, pressure and volume reached similar levels in both TO groups; both were significantly higher than their respective controls (P < 0.05). Parenchymal fraction (1 - air-space fraction) was significantly smaller after late TO (22.8 +/- 1.2%) than after early TO (31.3 +/- 0.5%). Type II density was 38.0 +/- 12.4 x 10(6)/mL after early TO and 84.0 +/- 24.3 x 10(6)/mL in control (P < 0.05); the difference between late TO and control was not significant. CONCLUSIONS: Late tracheal occlusion in fetal lambs caused more rapid lung growth than earlier TO, although ultimate lung size was similar in both groups. Late TO also resulted in greater air-space fraction and better preservation of the type II cell population than early TO. Late-gestation tracheal occlusion may therefore be preferable to prolonged occlusion initiated earlier.

Short-term tracheal occlusion in fetal lambs with diaphragmatic hernia improves lung function, even in the absence of lung growth.

BACKGROUND/PURPOSE: Prolonged tracheal occlusion (TO) accelerates lung growth but impairs surfactant production. Short-term TO results in less lung growth but preserves type II cell function. The authors studied the effects of short-term TO on lung physiology in diaphragmatic hernia. METHODS: Diaphragmatic hernia was created in 9 fetal lambs at 90 to 95 days. Five were left uncorrected (CDH), 4 underwent 2-week TO (108 to 122 days; CDH + TO). Five unoperated lambs served as controls. Near-term (136 days) fetuses were ventilated for 90 to 150 minutes. Pulmonary arterial pressure, postductal blood gases, quasistatic compliance, total lung capacity (TLC), and lung weight to body weight (LW/BW) were measured. RESULTS: There was an overall survival rate of 89% at full term. Short-term occlusion did not induce lung growth (TLC and LW/BW, 6.07 +/- 2.92 mL/kg and 0.022 +/- 0.008 in CDH, 4.86 mL/kg and 0.019 +/- 0.005 in CDH + TO, 10.81 +/- 3.55 mL/kg and 0.036 +/- 0.006 in controls, respectively). However, pulmonary hypertension in CDH (47.4 +/- 12.32/35.8 +/- 12.19 torr) was corrected by short-term occlusion (20.2 +/- 4.0/16.0 +/- 4.8 torr in CDH + TO, P< .05, single-factor analysis of variance [ANOVA]; similar to control). Best pO2 and pCO2 improved after occlusion (CDH, 48.6 +/- 6.7 torr and 107.1 +/- 34.3 torr, respectively; CDH + TO, 101.5 +/- 16.3 torr and 81.9 +/- 2.4 torr; control, 291.4 +/- 4.7 torr and 37.7 +/- 17.3), as did oxygenation index (P < .05, CDH vCDH + TO; CDH, 97.2 +/- 23.0; CDH + TO, 28.7 +/- 3.1; control, 5.6 +/- 0.6). CONCLUSIONS: Short-term TO corrects pulmonary hypertension and improves gas exchange in fetal lambs with diaphragmatic hernia despite failure to produce accelerated lung growth. Inducing lung maturation and correcting the physiological derangement in diaphragmatic hernia may be more important than achieving lung growth alone.

The unpredictable character of congenital cystic lung lesions.

BACKGROUND: The spectrum of congenital cystic disease of the lung ranges from hydrops and neonatal respiratory distress to asymptomatic lesions. Surgical management is dictated by the presence of symptoms, recurrent infection, and the potential risk of malignant transformation. METHODS: Since 1995, all consecutive patients with congenital cystic lung lesions underwent follow-up for symptoms, treatment, and correlation of presumptive with pathological diagnosis. RESULTS: Twelve cystic lung lesions were identified. Seven were diagnosed with mediastinal shift in utero; in 6 of 7, the shift subsequently resolved. Overall, 6 of 7 lesions that were followed up serially decreased in size. Two patients were symptomatic in utero; 1 underwent thoracoamniotic shunting, 1 pleurocentesis for impending hydrops. Postnatally, these 2, and 2 other newborns required urgent surgery. Five of 8 asymptomatic patients had elective resection by 16 months, and 4 await operation. In 6 of the 9 surgical cases (67%), there was a discrepancy between preoperative and pathological diagnosis. There were 4 hybrid congenital cystic adenomatoid malformation (CCAM)/sequestrations. CONCLUSIONS: At least 6 of 7 congenital cystic lung lesions decreased in size regardless of gestational age or presence of mediastinal shift. Antenatal intervention is therefore rarely indicated. Hybrid morphology may necessitate resection of stable, asymptomatic lesions to prevent the theoretical concern for associated malignancies as well as other complications of CCAM.

Primary laparoscopic placement of peritoneal dialysis catheters in children and young adults.

BACKGROUND: Primary placement of peritoneal dialysis catheters in children often requires suturing of the catheter into the pelvis. We describe our experience with a gasless laparoscopy technique in children and young adults. METHODS: During an 18-month period, 12 patients (mean age, 14 years) underwent primary laparoscopic placement of peritoneal dialysis catheters. A single umbilical port was used for abdominal wall elevation, telescope, and catheter. A needleholder was introduced via an accessory port at the future catheter exit site or through the umbilical port. Omentectomy was performed through the umbilical incision. The catheter was tunneled to the lateral abdominal wall. Follow-up data (>/= 15 months) included time to initiation of dialysis, hospitalization, and outcome. End points were cure, transplantation, or death. RESULTS: Diet was started on the day of surgery and dialysis on the following day. Four patients had seven complications, including leakage and entanglement of the catheter in tubal fimbriae. Long-term revision-free catheter survival was 67% at 24 months. CONCLUSIONS: This minimal access technique for primary placement of peritoneal dialysis catheters includes securing of the catheter tip in a dependent location and omentectomy. It allows nearly immediate use of the catheter, leads to a minimal hospital stay, and has acceptable long-term patency.