Shinjiro Hirose

Prenatal steroids for microcystic congenital cystic adenomatoid malformations

OBJECTIVE The purpose of this study is to evaluate the effect of prenatal steroid treatment in fetuses with sonographically diagnosed congenital cystic adenomatoid malformations (CCAMs). METHODS This was an institutional review board-approved retrospective review of 372 patients referred to the University of California, San Francisco (UCSF), for fetal CCAM. Inclusion criteria were (1) a predominately microcystic CCAM lesion sonographically diagnosed at our institution, (2) maternal administration of a single course of prenatal corticosteroids (betamethasone), and (3) no fetal surgery. CCAM volume-to-head ratio (CVR), presence of hydrops, mediastinal shift, and diaphragm eversion were assessed before and after administration of betamethasone. The primary end points were survival to birth and neonatal discharge. RESULTS Sixteen patients with predominantly microcystic CCAMs were treated with prenatal steroids. Three were excluded because of lack of follow-up information. All remaining fetuses (13/13) survived to delivery and 11/13 (84.6%) survived to neonatal discharge. At the time of steroid administration, all patients had CVR greater than 1.6, and 9 (69.2%) also had nonimmune hydrops fetalis. After a course of steroids, CVR decreased in 8 (61.5%) of the 13 patients, and hydrops resolved in 7 (77.8%) of the 9 patients with hydrops. The 2 patients whose hydrops did not resolve with steroid treatment did not survive to discharge. CONCLUSION In high-risk fetal patients with predominantly microcystic CCAM lesions, betamethasone is an effective treatment. This series is a pilot study for a prospective randomized trial comparing treatment of CCAM with betamethasone to placebo.

Long-term surgical outcomes in congenital diaphragmatic hernia: observations from a single institution

BACKGROUND/PURPOSE Surgical complications are common in survivors of congenital diaphragmatic hernia (CDH), but little is known about long-term incidence patterns and associated predictors. METHODS A cohort of 99 CDH survivors was prospectively followed at a single-institution multidisciplinary clinic. Data were gathered regarding the adverse surgical outcomes of hernia recurrence, chest and spinal deformity, and operative small bowel obstruction (SBO), and then were retrospectively analyzed in relation to perinatal and perioperative markers of disease severity to determine significant predictors. Statistical methods used included univariate and multivariate regression analysis, hazard modeling, and Kaplan-Meier analysis. RESULTS At a median cohort age of 4.7 (range, 0.2-10.6) years, 46% of patients with patch repairs and 10% of those with primary repairs had a hernia recurrence at a median time of 0.9 (range, 0.1-7.3) years after repair. Chest deformity was detected in 47%. Small bowel obstruction and scoliosis occurred in 13%. Recurrence and chest deformity were significantly more common with patch repair, liver herniation, age at neonatal extubation greater than 16 days, oxygen requirement at discharge, and prematurity. The strongest predictor of SBO was patch repair. Multivariate analysis showed that patch repair was independently predictive of recurrence and early chest deformity (odds ratios of 5.0 and 4.8, confidence intervals of 1-24 and 1-21, P < .05). Use of an absorbable patch was associated with the highest risk of surgical complications. CONCLUSIONS For long-term survivors of CDH, specific perinatal and operative variables, particularly patch repair, are associated with subsequent adverse surgical outcomes.

A Low-Frequency Versatile Wireless Power Transfer Technology for Biomedical Implants

Implantable biomedical sensors and actuators are highly desired in modern medicine. In many cases, the implants electrical power source profoundly determines its overall size and performance. The inductively coupled coil pair operating at the radio-frequency (RF) has been the primary method for wirelessly delivering electrical power to implants for the last three decades. Recent designs significantly improve the power delivery efficiency by optimizing the operating frequency, coil size and coil distance. However, RF radiation hazard and tissue absorption are the concerns in the RF wireless power transfer technology (RF-WPTT) [4], [5]. Also, it requires an accurate impedance matching network that is sensitive to operating environments between the receiving coil and the load for efficient power delivery. In this paper, a novel low-frequency wireless power transfer technology (LF-WPTT) using rotating rare-earth permanent magnets is demonstrated. The LF-WPTT is able to deliver 2.967 W power at ~ 180 Hz to an 117.1 Ω resistor over 1 cm distance with 50% overall efficiency. Because of the low operating frequency, RF radiation hazard and tissue absorption are largely avoided, and the power delivery efficiency from the receiving coil to the load is independent of the operating environment. Also, there is little power loss observed in the LF-WPTT when the receiving coil is enclosed by non-magnetic implant-grade stainless steel.

Perinatal Outcome of Conservative Management versus Fetal Intervention for Twin Reversed Arterial Perfusion Sequence with a Small Acardiac Twin

Objective: To examine the outcomes of patients with twin reversed arterial perfusion (TRAP) sequence in which the acardiac twin was ≤50% the weight of the pump twin. Methods: This was a retrospective study conducted with institutional review board approval. The records of all patients referred to UCSF for suspected diagnosis of TRAP between 1994 and 2009 were reviewed (n = 76). Patients with pregnancies complicated by TRAP with an acardiac twin ≤50% the weight of the pump twin were included (21 patients). Exclusion criteria were loss to follow-up (1 patient) and syndromic abnormalities in the pump twin (2 patients). Results: Of the 18 patients with viable pregnancies that met the criteria for analysis, 7 (39%) underwent radiofrequency ablation (RFA) of the acardiac twin and 11 (61%) underwent conservative management. None of the pump twins in either group had hydrops fetalis. Three of the 11 acardiac twins in the conservative management group did not undergo RFA because they did not have blood flow at presentation to UCSF. Survival to delivery was 100% (7/7) in the RFA group and 91% (10/11) in the conservative management group. When we eliminated from our analysis the 3 pregnancies in the conservative management group without blood flow to the acardiac twin, survival to delivery was 88% (7/8). The single death occurred in 1 of the 3 monochorionic-monoamniotic pregnancies in the conservative management group, all of whom had blood flow to the acardiac twin. There were no statistically significant differences in gestational age at delivery, birth weight or survival between the RFA and conservative management groups, even after stratification by blood flow. Conclusions: Conservative management with close monitoring appears to be a safe option for TRAP pregnancies in which the acardiac twin is ≤50% the weight of the pump twin.

Fetal Surgery for Myelomeningocele

Myelomeningocele is a morbid disease with a significant mortality within the first several decades of life. Fetal surgery is a promising therapy to prevent progressive neurological dysfunction. Unfortunately, fetal repair has not been shown thus far to improve leg or bladder function. Data from VUMC and CHOP suggest that hindbrain herniation and the need for VP shunting may be decreased. These potential improvements must be balanced with maternal safety considerations. The current funded trial in the United States will provide answers about the efficacy of fetal surgery for this disease, and, just as importantly, will provide the best data about the efficacy of the current multidisciplinary methods of treatment for MMC and the outcome of these children.

Prenatal intraabdominal bowel dilation is associated with postnatal gastrointestinal complications in fetuses with gastroschisis

OBJECTIVE The purpose of this study was to determine whether prenatal intraabdominal bowel dilation (IBD) is associated with increased postnatal complications in fetuses with gastroschisis. STUDY DESIGN A retrospective review was performed on all maternal-fetus pairs with prenatally diagnosed gastroschisis that was treated at the University of California San Francisco from 2002-2008. Postnatal outcomes were compared between fetuses with and without IBD. RESULTS Forty-three of 61 maternal-fetal pairs met the criteria for inclusion. Sixteen fetuses (37%) had evidence of IBD. Fetuses with IBD were significantly more likely to have postnatal bowel complications (38% vs 7%; P = .037). The presence of multiple loops of IBD (n = 6) as opposed to a single loop (n = 10) was associated highly with bowel complications and increased time to full enteral feeding and length of hospital stay (100% vs 0% [P = .001]; 44 vs 23 days [P = .034]; 69 vs 27 days [P = .001], respectively). CONCLUSION IBD is associated with increased postnatal complications in infants with prenatally diagnosed gastroschisis; however, this association seems to be limited to those with multiple loops of dilated intraabdominal bowel.

FETAL SURGERY FOR MYELOMENINGOCELE: PANACEA OR PERIL?

Myelomeningocele affects thousands of children worldwide with devastating consequences. In an effort to improve neurologic outcome, fetal surgery has been performed for myelomeningocele for the past 5 years. Sensorimotor function is not appreciably improved, although there may be a reduction in hindbrain herniation and a decreased need for ventriculoperitoneal shunting. The long-term clinical consequences of these findings are not clear. What is clear, however, is that further study in the form of a prospective, randomized trial is mandatory.

Magnamosis II: Magnetic Compression Anastomosis for Minimally Invasive Gastrojejunostomy and Jejunojejunostomy

BACKGROUND Previously we demonstrated the safety and patency of a magnetic compression anastomosis (magnamosis). We present the further development of this technique, with specific focus on optimizing device design for minimally invasive magnamosis. STUDY DESIGN The magnamosis device was designed to incorporate 3 features: 2 convex-concave radially symmetric halves that magnetically self-align, a central channel for immediate patency, and specially engineered radial topography of the mating surfaces to promote gradual remodeling. Each symmetrical half consists of a ring-shaped neodymium-iron-boron magnet encased in polycarbonate casing. Twenty-one young adult pigs underwent either magnetic gastrojejunostomy (n = 13) or jejunojejunostomy (n = 8). Animals were euthanized at 1, 2, 4, and 6 weeks after operation. Anastomoses were studied with contrast radiography, burst pressure, and histology. RESULTS Gastrojejunostomy: In all animals with successful placement of magnets, anastomoses were patent by contrast fluoroscopy, well healed by histologic examination, and showed excellent burst strength. Jejunojejunostomy: All animals had uneventful clinical courses, indicating that the magnamosis with immediate patency functioned properly without device dislodgement. At sacrifice, all magnamoses were patent, well healed by histology, and had burst strengths that equaled or exceeded that of traditional stapled anastomoses. CONCLUSIONS Minimally invasive placement of a custom magnetic device in the stomach and jejunum allows intraluminal self-alignment and subsequent compression anastomosis over 3 to 10 days. The magnamosis is immediately patent and develops strength equal to or greater than that of hand-sewn or stapled anastomoses. Magnamosis is effective in the pig model, and may be a safe, effective, and minimally invasive alternative to current anastomotic strategies in humans.

Magnamosis III: delivery of a magnetic compression anastomosis device using minimally invasive endoscopic techniques

PURPOSE Magnamosis creates a secure sutureless anastomosis through magnetic compression. In this study, we further develop and test delivery devices capable of creating a secure duodeno-colonic anastomosis using available minimally invasive endoscopic techniques. METHODS Eight pigs underwent general anesthesia. Colonoscopy was used to deliver 1 magnetic ring to the hepatic flexure. Simultaneously, upper endoscopy delivered the other magnetic ring into the duodenum using a variety of techniques. The 2 magnetic rings were brought into magnetic proximity under laparoscopic guidance. The pigs were recovered and examined daily followed by sacrificing at 1, 2, 4, and 6 weeks. RESULTS The device designed to deliver and release each magnetic ring evolved from using a guide wire and balloon devices to redesigning the magnetic ring casing with a groove to accommodate an endoscopic snare. Laparoscopic visualization assured safe magnet mating of intestinal segments. The duodeno-colonic anastomoses created with the snare yielded widely patent anastomoses. In vitro testing revealed excellent burst pressure. Histology revealed complete healing as early as 1 week. CONCLUSION We redesigned the magnamosis device to facilitate delivery by endoscopic techniques. The snare technique allows endoscopic positioning and controlled release of the magnetic rings for a secure side-to-side duodeno-colonic anastomosis.

The influence of portoenterostomy on transplantation for biliary atresia

After portoenterostomy (PE) for biliary atresia (BA), many patients suffer progressive deterioration of liver function and ultimately require liver transplantation. We retrospectively reviewed a single centers experience with pediatric liver transplantation for BA from 1988 to 2002. Sixty‐six patients underwent 69 liver transplants for BA. Forty‐two (63%) patients had previously undergone Kasai PE, 11 (17%) biliary appendicoduodenostomy (BAD), and 13 (20%) had no prior biliary drainage (NBD). The BAD procedure offered only short‐term biliary drainage—the mean interval between PE and transplant was more than twice that for Kasai patients than for BAD patients (132 versus 49 weeks). The transplants included 11 cadaveric partial, 27 cadaveric whole, and 31 living related transplants. Three patients required retransplant. Prior PE did not increase the incidence of major perioperative complications or unplanned reexploration. After transplant, the 1‐, 5‐, and 10‐year actuarial graft survival rates were 87%, 86%, and 80%, respectively. The 1‐, 5‐, and 10‐year actuarial patient survival rates were 91%, 89%, and 83%. PE remains an important bridge to transplant. In conclusion, transplantation for BA offers excellent long‐term graft and patient survival. (Liver Transpl 2004;10:1279–1286.)