Onset of brain injury in infants with prenatally diagnosed congenital heart disease

BACKGROUND

The exact onset of brain injury in infants with congenital heart disease (CHD) is unknown. Our aim was, therefore, to assess the association between prenatal Doppler flow patterns, postnatal cerebral oxygenation and short-term neurological outcome.

METHODS

Prenatally, we measured pulsatility indices of the middle cerebral (MCA-PI) and umbilical artery (UA-PI) and calculated cerebroplacental ratio (CPR). After birth, cerebral oxygen saturation (rcSO2) and fractional tissue oxygen extraction (FTOE) were assessed during the first 3 days after birth, and during and for 24 hours after every surgical procedure within the first 3 months after birth. Neurological outcome was determined preoperatively and at 3 months of age by assessing general movements and calculating the Motor Optimality Score (MOS).

RESULTS

Thirty-six infants were included. MOS at 3 months was associated with MCA-PI (rho 0.41, P = 0.04), UA-PI (rho -0.39, P = 0.047, and CPR (rho 0.50, P = 0.01). Infants with abnormal MOS had lower MCA-PI (P = 0.02) and CPR (P = 0.01) and higher UA-PI at the last measurement (P = 0.03) before birth. In infants with abnormal MOS, rcSO2 tended to be lower during the first 3 days after birth, and FTOE was significantly higher on the second day after birth (P = 0.04). Intraoperative and postoperative rcSO2 and FTOE were not associated with short-term neurological outcome.

CONCLUSION

In infants with prenatally diagnosed CHD, the prenatal period may play an important role in developmental outcome. Additional research is needed to clarify the relationship between preoperative, intra-operative and postoperative cerebral oxygenation and developmental outcome in infants with prenatally diagnosed CHD.

Anatomical description of the umbilical arteries and impact of their ligation on pelvic and perineal vascular supply after cystectomy in women

OBJECTIVE

In radical cystectomy, the surgeon generally ligates the umbilical artery at its origin. This artery may give rise to several arteries that supply the sexual organs. Our aim was to evaluate pelvic and perineal devascularisation in women after total cystectomy.

PATIENTS AND METHODS

We carried out a prospective anatomical and radiological study. We performed bilateral pelvic dissections of fresh adult female cadavers to identify the dividing branches of the umbilical artery. In parallel, we examined and compared the pre- and postoperative imaging investigations [magnetic resonance imaging (MRI) angiography] in patients undergoing cystectomy for benign disease to quantify the loss of pelvic vascularisation on the postoperative images by identifying the occluded arteries.

RESULTS

The anatomical study together with the radiological study visualised 35 umbilical arteries (n = 70) with their branching patterns and collateral arteries. The uterine artery originated from the umbilical artery in more than 75% of cases (n = 54) of the internal pudendal artery in 34% (n = 24) and the vaginal artery in 43% (n = 30). The postoperative MRI angiograms showed pelvic devascularisation in four patients. Devascularisation was dependent on the level of surgical ligation. In the four patients with loss of pelvic vascular supply, the umbilical artery had been ligated at its origin.

CONCLUSION

The umbilical artery gives rise to various branches that supply the pelvis and perineum. If the surgeon ligates the umbilical artery at its origin during total cystectomy, there is a significant risk of pelvic and perineal devascularisation.

Using lateral radiographs to determine umbilical venous catheter tip position in neonates

We aimed to assess the difference in measurement of the distance of the UVC tip from the diaphragm between (Anteroposterior) AP and lateral radiographs and to determine the reliability of the measurement of UVC tip distance from the diaphragm between the two views. A retrospective review of paired AP and lateral radiographs taken to assess UVC tip position was carried out in 25 infants was conducted and reliability analysis was carried out. There was a significant difference in the mean (SD) distance of the UVC catheter above the diaphragm between the AP and lateral radiographs: 8.7 (7.8) mm versus 11.6 (7.3) mm (p = 0.003) respectively. Measurements using lateral radiographs were more reliable (Intraclass correlation coefficient: 0.99 vs. 0.93). Inter-observer reliability analysis yielded similar results. Lateral radiographs are more reliable in measurement of UVC tip position and should be performed in conjunction with AP films to aid in determining UVC position.

[Interstitial laser coagulation in Twin Reversed Arterial Perfusion sequence]

Twin Reversed Arterial Perfusion (TRAP) sequence complicates about 1% of all monochorionic twin pregnancies and about 1 to 35000 of all pregnancies. It involves an acardiac twin whose structural defects are incompatible with life, and an otherwise normal "pump" co-twin. As the blood flow in the acardiac twin is reversed, it keeps on growing owing to the oxygenated blood from the co-twin. Here we report a case of monochorionic, diamniotic twin pregnancy after ICS/-ET complicated with TRAP sequence, diagnosed at 11 weeks of pregnancy The unusual finding in this case was the residual heart in the so called acardiac twin. Gradually the normal twin developed signs of hemodynamic compromise. Reversed a-wave in ductus venosus was observed. The acardiac twin showed subcutaneous oedema. On 24 November 2011 a successful interstitial ultrasound-guided laser coagulation was performed at 16 weeks of gestation. 17G needle and 0.6 mm laser fibre were used. The needle was introduced into the pelvic region of the acardiac twin through the abdominal wall. A series of laser bursts lasting 5-10 seconds were fired, until cessation of blood flow in the pelvic vessels and umbilical cord of the acardiac twin was confirmed using colour Doppler. The course of the intervention was uneventful. Routine steroid therapy was administered at 27 weeks of gestation. At 32 weeks the patient was hospitalized and oral antibiotics were administered due to premature rupture of the membranes and suspicion of intrauterine growth retardation of the pump twin. The patient delivered spontaneously at completed 33 weeks of pregnancy (weight 1805g, Apgar 10). After the delivery a stage 2 intraventricular hemorrhage and jaundice were observed in the neonate. Phototherapy was administered and the mother and the child were eventually discharged from the hospital, both in good general condition. Since then, two more successful interstitial laser coagulations in TRAP sequence were performed in our institution. The essence of the treatment of TRAP sequence is cessation of the blood flow from the pump to the acardiac twin. Fetoscopic cord ligature or coagulation, and laser or radiofreqency ablations of the acardiac twin vessels, are the possible methods of intervention. The interstitial laser coagulation of the acardiac twin is less invasive than fetoscopic umbilical cord coagulation, as the outer diameter of the 17G needle is much smaller. A meticulous comparison of these methods would require a randomised study but at 16 weeks of MCDA twin pregnancy interstitial laser coagulation seems to be the method of choice. The outcome of the procedure and possible treatment options in case of TRAP together with the review of literature, are presented in the article.

Validation of Quintero stage III sub-classification for twin-twin transfusion syndrome based on visibility of donor bladder: characteristic differences in pathophysiology and prognosis

OBJECTIVE

To validate the Quintero stage III subclassification for twin-twin transfusion syndrome (TTTS) based on visibility of the bladder of the donor twin.

METHODS

Between July 2002 and August 2006, there were 131 pregnant Japanese women affected by severe TTTS before 26 weeks' gestation, treated with fetoscopic laser surgery at five centers in Japan, whose pregnancies continued beyond 22 weeks. Outcome data were available in all cases and surviving infants were followed up for at least 6 years. This study focused on the Stage III TTTS patients. These were subclassified into Stage III atypical (abnormal Doppler flow with visible donor bladder) and Stage III classical (abnormal Doppler flow with non-visible donor bladder) groups. Perioperative data and postnatal outcomes were compared between the groups.

RESULTS

Seven Stage I, 22 Stage II, 82 Stage III and 20 Stage IV pregnancies continued beyond 22 weeks. There was a significantly higher incidence of absent or reversed end-diastolic velocity in the umbilical artery (UA-AREDV) of the donor in Stage III atypical than in Stage III classical patients (83.8% vs. 53.3%, P = 0.004). Stage III atypical cases also had a significantly higher incidence of arterioarterial (AA) anastomoses (72.9% vs. 17.8%, P < 0.001) and intrauterine fetal demise (IUFD) of the donor (43.2% vs. 13.3%, P = 0.002). However, there were no differences in overall survival or in abnormal brain scans of surviving infants. Donors with both UA-AREDV and AA anastomoses had a significantly higher incidence of IUFD compared with the others (53.3%, P < 0.001).

CONCLUSIONS

Quintero stage III atypical was characterized by a high incidence of AA anastomoses and UA-AREDV of the donor, resulting in IUFD. Subclassification of Stage III based on visibility of the bladder of the donor twin was adequate for and compatible with differentiating prognosis and pathophysiology.

Surgical retrieval of a transected umbilical artery catheter

UMBILICAL ARTERY catheters (UACs) are commonly used in neonates and particularly in premature babies. They are crucial in enabling accurate blood pressure monitoring, blood gas analysis, and blood sampling. There is a relatively low rate of major complications with these catheters; however, complications may result from fracture or transection of the catheter.1,2Complications of retained UACs include hemorrhage and thromboembolic events. Long-term sequelae have also been described, including limb abnormalities as a result of ischemia and recurrent umbilical infection following unrecognized retained UACs.2,3We report a case of accidental transection of a UAC and subsequent migration of the catheter into the arterial circulation. This resulted in the premature baby requiring a laparotomy to retrieve the catheter. We describe the events leading to the transection, present its operative management, and offer suggestions for preventing this complication.

The role of laser surgery in dissecting the etiology of absent or reverse end-diastolic velocity in the umbilical artery of the donor twin in twin-twin transfusion syndrome

OBJECTIVE

This study was undertaken to gain insight on the cause of absent or reverse end-diastolic velocity (AREDV) in the umbilical artery (UA) of the donor twin by analysis of individual placental mass and vascular anastomoses in patients with twin-twin transfusion syndrome (TTTS) treated with laser.

STUDY DESIGN

TTTS patients who successfully underwent selective laser photocoagulation of communicating vessels (SLPCV), 16 and 26 weeks' gestation, with both twins born alive and complete Doppler and placental data were considered eligible for the study. Doppler examination of the UA was performed before and 24 hours after SLPCV. Abnormal UA Doppler findings were defined as persistent AREDV. Pre- and post-SLPCV UA Doppler results yielded the following 4 groups: (1) normal-normal; (2) normal-abnormal; (3) abnormal-normal; and (4) abnormal-abnormal. The types of vascular anastomoses were categorized during surgery. Individual placental territory (IPT) was defined as individual placental weight divided by total placental weight x 100.

RESULTS

There were 132 cases in group 1 and no patients in group 2. AREDV resolved in 78% (28/36) of patients (group 3) and remained unchanged in 22% (8/36) (group 4). The mean IPT-donor in group 4 was significantly smaller than in group 1 (P = .015). Patients with preoperative AREDV (groups 3 and 4) were more likely to have artery-to-artery anastomoses (P = .002). However, AREDV resolved in 57% (16/28) patients without artery-to-artery anastomoses.

CONCLUSION

Preoperative AREDV may result from a small IPT, placental vascular anastomoses, or both. AREDV resulting from a small IPT may have a similar cause to that of singletons, and may be inferred by lack of postoperative resolution. Resolution of AREDV after SLPCV implies the presence of an adequate IPT and removal of donor hypotension.

Elevated plasma tissue factor levels in neonates with umbilical arterial catheter-associated thrombosis

Catheterization of the umbilical artery has been a useful aid in the management of sick neonates for the past few decades. However, it is associated with various complications. Reported studies strongly suggest a significant role of intravascular catheterization in the development of aortic thrombi. Increase in thrombosis of large vessels is believed to be related to mechanical injury in the catheterized vessels, which provide direct exposure of blood to tissue factor (TF), the primary cellular initiator of the extrinsic coagulation pathway. This study was conducted to determine the levels of plasma TF, tissue factor pathway inhibitor (TFPI) and D-dimer (DD) in infants with umbilical arterial catheter (UAC)-associated thrombosis. Quantification of TF was carried out using an in-house sandwich ELISA, whereas TFPI and DD levels were measured with commercial immunoassay kits. Infants with UAC inserted were found to have significantly higher levels of plasma TF (p < 0.001) than baseline levels. However, there were no significantly elevated levels of TFPI or DD. Infants with UAC-associated thrombosis demonstrated a greater increase of TF level (median: 414.5 pg/mL; range: -76.0, 6667.0) than infants without UAC-associated thrombosis (105.0 pg/mL; -976.0, 9480.0; p = 0.009) following UAC insertion. Our findings indicate that quantification and monitoring of TF levels could predict thrombus formation in infants with indwelling UAC. Following umbilical arterial catheterisation, infants with an approximately 3-fold rise in plasma TF levels were most at risk of developing abdominal aorta thrombosis as confirmed by real-time abdominal ultrasonography.

Use of fresh human placenta for microsurgical training

Microsurgery requires considerable practice before any attempt is made at clinical application. Live animals represent the ideal training medium; however, unlimited access to the animal laboratory is not always possible. In such situations, segments of fresh human placenta provide ideal specimens for microsurgical practice. They are readily available and abundant in a variety of vessels, and require a minimum of dissection.

Operative fetoscopy via telesurgery

We describe a case in which telesurgical consultation from Tampa, Florida, USA was used to accomplish operative fetoscopy in Santiago, Chile for the treatment of a twin pregnancy involving an acardiac twin. The procedure was successful and a healthy infant was delivered at 37.5 weeks. Operative fetoscopy, a surgical approach to correct birth defects in utero via combined ultrasound and endoscopy, is only available in a handful of centers worldwide. Telesurgery makes use of telecommunication to allow a surgeon at a primary operating site to consult with another experienced surgeon for complex surgical cases. This case illustrates the potential for ultrasound and telesurgery to expand the horizons of operative fetoscopy.

Impact of laser coagulation in severe twin-twin transfusion syndrome on fetal Doppler indices and venous blood flow volume

OBJECTIVE

To evaluate the impact of fetoscopic laser coagulation of placental anastomoses in severe twin-twin transfusion syndrome on fetal Doppler indices and umbilical vein blood flow volume as calculated with Doppler and two-dimensional ultrasound.

METHODS

Thirty-two cases of second-trimester severe twin-twin transfusion undergoing laser therapy were examined with serial ultrasound before and 1, 3 and 5 days after therapy. Pulsatility indices in the umbilical artery and ductus venosus were measured. Blood volume flow at the level of the intra-abdominal umbilical vein was calculated by means of Doppler and two-dimensional ultrasound. The development of hydropic signs in donors was recorded. Perinatal outcome in terms of neonatal survival was recorded for all cases.

RESULTS

In recipients, ductus venosus pulsatility index decreased progressively after therapy and, by day 5, median pulsatility index was significantly lower than that before therapy (0.97 vs. 0.82, P < 0.0001). Umbilical vein blood flow volume in recipient twins showed no significant variations before and after laser. In donors, umbilical artery pulsatility index decreased significantly by the first day following therapy (2.1 vs. 1.6, P < 0.0001). Previously absent or reverse umbilical end-diastolic flow reappeared after therapy in 46% (7/15) of donors. Ductus venosus pulsatility index in donors increased significantly by day 1 after therapy (0.99 vs. 1.35, P < 0.0001) but, over days 3 and 5, it returned towards preoperative values. Umbilical vein flow volume measurements (mL/min/kg) in the donor increased by approximately 50% the day after treatment (151 vs. 232, P < 0.0001) and remained elevated. Umbilical vein flow volume before laser therapy was significantly lower in donors compared to recipients (151 vs. 260, P < 0.0001), but the difference was non-significant after treatment (240 vs. 267). One or more hydropic signs developed in eight (25%) donors during the 5 days' observation after therapy.

CONCLUSIONS

Laser therapy induced important changes in fetal hemodynamic parameters, resulting in a reversion of the disturbances associated with severe twin-twin transfusion syndrome. The recipient twin showed a progressive improvement of previous signs of right cardiac overload. The donor experienced a substantial increase in umbilical vein blood volume flow accompanied by a transitory state of relative right overload, which may explain the development of transient hydropic signs in a proportion of donors.

Use of an endoscopic suturing device for laparoscopic resection of the apex of the bladder and umbilical structures in normal neonatal calves

OBJECTIVE

To develop a laparoscopic technique using an endoscopic suturing device for the resection of the apex of the bladder and the umbilical structures in large-animal neonates. Study Design-Experimental study. Animals or Sample Population-Seven healthy male Holstein calves.

METHODS

A laparoscopic technique for resection of the apex of the bladder was developed on 2 calf cadavers, then evaluated on 5 anesthetized calves. The calves were positioned in dorsal recumbency, and 4 ventral abdominal portals were used. The umbilical vessels were double-ligated using an endoscopic suturing device and subsequently transected. The apex of the bladder was transected between a row of laparoscopic clips applied near the apex and atraumatic laparoscopic forceps applied distally; then, the edges were apposed using an endoscopic suturing device. The dissected umbilical remnants were removed from the abdomen through a small incision centered at the umbilicus. One month later, the calves were euthanatized and a second-look laparoscopy performed; then, bladders were collected for gross and histologic examination.

RESULTS

No major complications occurred during or after surgery. The endoscopic suturing device permitted both effective ligation of the umbilical vessels and closure of the bladder. During second-look laparoscopy, healing of the peritoneal surface of the bladder and umbilical vessels was assessed to be excellent in 4 calves. A focal adhesion of omentum to the bladder suture line was observed in 1 calf. Focal adhesions of the omentum to the umbilical incision site occurred in 2 calves. The bladder mucosa was completely healed at the surgical sites.

CONCLUSION AND CLINICAL RELEVANCE

Resection of the apex of the bladder and umbilical vessels in calves can be accomplished laparoscopically using an endoscopic suturing device.

Anticipating twin-twin transfusion syndrome in monochorionic twin pregnancy. Is there a role for nuchal translucency and ductus venosus blood flow evaluation at 11-14 weeks?

Twin-twin transfusion syndrome is a major complication of monochorionic twin pregnancies. In foetuses from monochorionic twinning the presence of increased nuchal translucency thickness (NT) has been associated with an increased risk of developing this syndrome. One of the presumed mechanisms of increased NT is early cardiac failure, indirectly indicated by abnormal blood flow in the ductus venosus. We present eleven cases of monochorionic twin pregnancies in which nuchal translucency thickness and ductus venosus blood flow evaluation was performed at 11-14 weeks. In the two cases presenting with nuchal translucency discrepancy between the two foetuses along with anomalous ductus venosus blood flow in the foetus with increased nuchal translucency, twin-twin transfusion syndrome (TTTS) eventually developed. In none of the twins displaying no inter-twin difference in NT measurements and in those with discrepant NT but normal flow in both ductus venosus, was the progression to TTTS observed. In the two cases which developed TTTS, foetoscopic laser coagulation of the vascular anastomosis was successfully carried out at 18 weeks and normalisation of the venous return was registered. These findings suggest that the association of increased NT and abnormal flow in the ductus venosus in monochorionic twins may be an early manifestation of haemodynamic imbalance between the donor and the recipient eventually manifested as twin-twin transfusion syndrome. Further studies, however, are necessary to establish the potential role of the combination of NT and ductus venosus blood flow assessment as a screening method for TTTS.

Laparoscopically assisted resection of umbilical structures in foals

A technique for laparoscopically assisted resection of umbilical structures in foals was developed. Eleven foals ranging from 8 to 42 days old underwent this procedure. Results of bacteriologic culture of umbilical structures were positive in 7 foals. Mean duration of anesthesia was 99 minutes, of which the initial 20 to 25 minutes were typically devoted to positioning and preparation of the foal for surgery. Major complications did not develop in any foal. Minor complications, such as slippage of the endoscopic ligating clip or laceration of the bladder during dissection, were dealt with successfully during the procedure. Potential benefits of use of laparoscopy (i.e., decreased postoperative morbidity, smaller incisions, and increased intraoperative access to structures) must be carefully weighed against the risks of increased duration of anesthesia. However, anesthetic-related complications were not observed in any foal.

Treatment of acardiac twinning

BACKGROUND

The twin reversed-arterial-perfusion sequence is a complication of monochorionic twin pregnancies characterized by the hemodynamic dependence of a "recipient" twin from a "pump" twin. The recipient twin exhibits lethal abnormalities including acardia and acephaly. The pump twin has a mortality rate of 50% as a result of high-output heart failure.

CASE

The blood supply to an acardiac-acephalus twin was interrupted at 24 weeks' gestation using endoscopic laser coagulation. The co-twin was delivered at 35 weeks and had an uneventful neonatal course following correction of a persistent patent ductus arteriosus. Review of the literature reveals 22 cases of acardiac twinning treated with invasive procedures, seven of them using endoscopic laser coagulation. Pump twin mortality with fetal surgery was 13.6% in comparison with 50% mortality with expectant management (P < .001).

CONCLUSION

Fetal surgery is the best available treatment for acardiac twinning. Endoscopic laser coagulation at or before 24 weeks and endoscopic or sonographic guided umbilical cord ligation after this gestational age seem to be the best treatments for this condition.

-Interruption of umbilical blood flow in an acardiac twin by endoscopic laser coagulation-

We report on the successful intrauterine surgical treatment of a twin pregnancy with an acardiac fetus. At 18 weeks of gestation the patient presented with polyhydramnios and a hydropic acardius acephalus and the donor twin showed signs of congestive heart failure. Colour Doppler ultrasound allowed localisation of the communicating vessels running on the placental surface towards the umbilicus of the acardiac twin. At 20 weeks we performed endoscopic laser coagulation of the umbilical vessels of the acardiac twin. A sheath (9.8 Charriere) with a 1.9 mm diameter rigid fetoscope (field of vision 60 degrees) was introduced percutaneously under local anesthesia into the amniotic cavity of the "pump" twin. Under sonographic control the fetoscope was directed towards the communicating vessels on the placental surface. A Nd-YAG laser (0.4 mm diameter fiber) was used to coagulate two vessels, artery and vein, until interruption of the reversed arterial perfusion was accomplished. Tricuspid regurgitation of the normal twin disappeared throughout the following two weeks and no further complications occurred throughout pregnancy. At 39 weeks a healthy girl was delivered vaginally. No at the age of 3 months she is developing normally. Minimal invasive endoscopic laser coagulation of the umbilical vessels of the acardiac twin appears to be the optimal currently available treatment for the normal twin, for which otherwise a high mortality ( > 50%) and morbidity must be expected.

Debridement of periumbilical necrotizing fasciitis: importance of excision of the umbilical vessels and urachal remnant

The operation of a neonate with periumbilical necrotizing fasciitis consisted of (1) excision of infected skin, fat, and fascia (including the umbilicus); (2) a limited laparotomy, with ligation and excision of the umbilical vessels and urachal remnant; and (3) placement of a temporary silastic patch over the central abdominal defect. Pathological sections confirmed the spread of infection along the vessels and urachal remnant. Excision of the vessels and urachal remnant may be crucial to survival from periumbilical necrotizing fasciitis.

Blunted response of maternal ovine placental lactogen levels to arginine stimulation after single umbilical artery ligation in pregnant sheep

Ovine placental lactogen levels in the maternal circulation are significantly reduced after single umbilical artery ligation in pregnant sheep. We report the ovine placental lactogen response to high-dose amino acid stimulation in four ewes with fetuses that underwent single umbilical artery ligation and six control ewes with fetuses that underwent sham operation. After maternal infusion with 50 gm of arginine in 350 ml of distilled water, mean ovine placental lactogen levels in ewes with fetuses that underwent single umbilical artery ligation increased by 170%, while mean levels in control ewes increased by 294%. Maternal infusions with hypertonic saline solution of osmolality and volume equal to those of the arginine solutions failed to increase maternal ovine placental lactogen levels. Fetal well-being, both during and after the maternal arginine infusions, was confirmed by unchanged fetal arterial blood gases and catecholamines. The ovine placental lactogen levels in the fetal circulation were not altered by maternal arginine infusion. These data suggest that the correlation between maternal ovine placental lactogen levels and functioning placental mass may be enhanced by arginine stimulation. The possible use of this provocation of placental lactogen levels as a test of placental function in clinical practice is discussed.

Surgical management of umbilical masses with associated umbilical cord remnant infections in calves

Intra-abdominal umbilical cord remnant infections were diagnosed in 21 calves during a 5-year period. The urachal remnant alone was involved in 15 calves, umbilical artery remnant alone in 1 calf, and the umbilical vein remnant alone in 4 calves. Both urachus and umbilical vein were involved in 1 calf. All cases were managed surgically by ventral celiotomy. Infected urachal remnants not extending to the bladder, infected umbilical artery remnant, and infected umbilical vein remnants not extending to the liver were dissected free of surrounding adhered structures, ligated proximal to the infected segment, transected, and removed. Infected urachal remnants extending to the bladder were similarly isolated and removed after resection of the attached bladder apex. Infected umbilical vein remnants extending to the liver were marsupialized. Of 19 calves available for follow-up from 1 to 32 months after surgery, 15 recovered without any postoperative complications, 3 had short-term complications, and 1 calf developed an incisional hernia.

A new perfusion circuit for the newborn with lung immaturity: extracorporeal CO2 removal via an umbilical arteriovenous shunt during apneic O2 diffusion

In spite of improved prophylaxis and therapy, the respiratory distress syndrome is still a major cause of morbidity and mortality in premature babies. Owing to the fact that a number of patients are unresponsive to other methods of neonatal care, an increasing number of perinatal centers have started to treat this group of patients with extracorporeal membrane oxygenation successfully. To make the extracorporeal gas exchange more practicable for the neonate directly after birth, a modification of this method using an umbilical arteriovenous shunt for CO2 removal in apneic premature lambs as an animal model was evaluated. A miniaturized low-resistance extracorporeal circuit that is totally incorporated in a regular intensive care baby incubator was developed. The benefit of using extracorporeal CO2 removal in very low birth weight newborns could be a conditioning of the premature lung during a short period of bypass, after which ventilation at nontraumatic pressures and nontoxic O2 concentrations would become possible.

Vesico-umbilical fistula: a complication of umbilical artery cutdown

A vesico-umbilical fistula occurred following cut down for catheterization of the umbilical artery in a premature infant; a previously unreported complication. Knowledge of the variations in anatomical structure of the urachus and umbilical arteries at birth will help to prevent this complication.

Vascular distal ureteral obstruction

The diagnosis, treatment and results of 6 patients with 7 obstructed distal ureters secondary to vascular compression are presented. Three ureters were treated by transection of the offending vessels and the remaining 4 required additional ureteroneocystostomy.

Translocation of the umbilical artery to the lower abdomen: an adjunct to the postoperative monitoring of arterial blood gases in major abdominal wall defects

A technique is presented for preserving the umbilical arteries for postoperative monitoring of arterial blood gases after repair of giant omphaloceles and gastroschisis. Translocation of the arteries to the lower abdominal wall removes them from the operative field and allows cannulation and long-term blood sampling. Complications have been minimal and the improved application of modern pulmonary support mechanisms has materially contributed to better patient management. The technique is a simple one and may prove applicable to other major newborn medical and surgical diseases involving respiratory insufficiency.