Development of a novel method for operating magnetic particles, Magtration Technology, and its use for automating nucleic acid purification

Magnetic particles are useful for simple and efficient nucleic acid extraction. To achieve fully automated nucleic acid extraction and purification using magnetic particles, a new method for operating magnetic particles, Magtration Technology, was developed. In this method, magnetic separation is performed in a specially designed disposable tip. This enables high recovery of magnetic particles with high reproducibility. The features of this technology are (i) a simple mechanism for process control and (ii) flexible software to enable adaptation to commercially available reagents. Automated instruments based on Magtration Technology were developed and used for nucleic acid extraction. Total DNA, total RNA and plasmids were purified by Magtration Technology at an efficiency comparable to that of manual methods.

Multipurpose robot for automated cycle sequencing

Paramagnetic beads have the superior advantages of easy separation and resuspension by controlling the magnetic filed. Previously, we have developed Magtration technology to automate paramagnetic bead handling and have built several automated instruments that handle 1-12 samples simultaneously. To achieve more high-throughput sample processing, two types of a 96-arrayed Integrated Magtration Unit (IMU) were developed, one installed with electromagnets and the other with thin rod-shaped magnets made of neodymium. A multipurpose robot (SX-96GC) equipped with the IMU was also developed for fully automatic processing of 96 samples in parallel. The cleanup of dye-terminator sequencing products was performed using the robot installed with the permanent magnet version of IMU. The results had quality comparable to those by the same protocol in manual handling or to those by the conventional protocols. The robot processed 96 samples in a microplate within 30 min. The protocol that can purify 384 samples within 1 h by processing two microplates concurrently was successfully designed.

Laparoscopic muscle electrostimulation during laparoscopy-assisted anorectal pull-through for high imperforate anus

PURPOSE

Our technique for laparoscopic muscle electrostimulation during laparoscopy-assisted anorectal pull-through (LAARPT) for high imperforate anus (HIA) in 3 patients is described.

METHODS

The distal rectum and rectourethral fistula is dissected laparoscopically. A muscle stimulator is passed through one of the trocars and used to identify the center of contraction of the levator ani. The same muscle stimulator is used to identify the center of the external sphincter muscle transcutaneously. An intravenous cannulation device (SURFLO Flash IV catheter, TERUMO, CO, Yamanashi, Japan) is inserted through this proposed anus and observed piercing the center of the levator ani. A guide wire is passed through the SURFLO, and a series of dilators are passed along it to create a canal for the colonic pull-through. An anoplasty then was performed.

RESULTS

Our technique was successful in all patients. Laparoscopic electrostimulation produced good levator ani contraction in patients I and II and weak contraction in patient III. Patients I and II have symmetrical anal contraction during rectal examination, but patient III has poor contraction. Stool frequency is decreasing in all.

CONCLUSION

Direct laparoscopic observation of levator ani contraction allows intraoperative assessment of functional contractility and assists in the accurate placement of the colonic pull-through.

Ectopic distal location of the papilla of vater in congenital biliary dilatation: Implications for pathogenesis

BACKGROUND/PURPOSE

This study investigates the relationship between the location of the papilla of Vater and the length of the common channel in patients with congenital biliary dilatation (CBD).

METHODS

Cholangiograms from 121 CBD patients and 13 normal controls were the subjects for this study. A length index defined as the length of the common channel divided by the height of the second lumbar vertebra was used for standardization.

RESULTS

In the controls, the papilla of Vater was located in the middle of the descending or second part of the duodenum in all cases. In 39 (32.2%) of the 121 CBD patients papilla of Vater was located in the descending duodenum (group I), and in 82 (67.8%) it was distal to the descending duodenum (group II). The average length index of the common channel in group II was significantly longer than in group I (1.123 +/- 0.374 v 0.660 +/- 0.246; P <.001). Findings for the common bile duct were similar.

CONCLUSIONS

There is a significantly higher incidence of ectopic distal location of the papilla of Vater in CBD patients than in controls. The more distal the location of the papilla of Vater, the longer the common bile duct and the common channel.

Magnetic resonance cholangiopancreatography in assessing the cause of acute pancreatitis in children

Magnetic resonance cholangiopancreatography (MRCP) is a new noninvasive method of obtaining images of the pancreaticobiliary tract. Recent advances in MR technology and image quality have made it easy to diagnose structural abnormalities of the pancreaticobiliary tract (SAPBT) in children. To examine the usefulness of MRCP in assessing the cause of acute pancreatitis in children, we performed MRCP in 16 patients with acute pancreatitis. The study population was divided into two groups according to the cause of acute pancreatitis as follows: group 1 consisted of seven patients sonographically diagnosed with choledochal cysts; and group 2 consisted of nine patients with no obvious cause of acute pancreatitis. Non-breath-hold MRCP using the half-Fourier, single-shot, fast spin-echo imaging method was performed within 7 days after the onset of pancreatitis. Abnormal union of the pancreaticobiliary junction was detected in six of seven group 1 patients and in one of nine group 2 patients. Pancreatic divisum was detected in one patient of group 1, but could not be confirmed in one patient of group 2. Dilatation of the main pancreatic duct was detected in one patient of group 1 and in three patients of group 2. Our results suggest that MRCP is a useful, noninvasive method of identifying and ruling out SAPBT as a cause of acute pancreatitis in children with early-stage pancreatitis.

A case of biliary atresia with duplication of the common bile duct

The authors report a case of biliary atresia (BA) with duplication of the common bile duct. A 1-month-old girl was referred for investigation of persistent jaundice. BA was suspected and confirmed with intraoperative cholangiography. A portoenterostomy was performed at 50 days of age. During dissection of the fibrous remnant of the common bile duct, a separate fibrous bile duct remnant running in parallel on the left, was identified. Histologically, there was bile duct proliferation at the porta hepatis of the left bile duct remnant. A diagnosis of BA with duplicated common bile duct was made. Postoperative course was uneventful, and at a follow-up assessment at 7 months, she was jaundice free, and her progress has been unremarkable.

Tubed latissimus dorsi musculocutaneous flaps for esophageal replacement in puppies: long-term follow-up

PURPOSE

The aim of this study was to show that a tubed latissimus dorsi musculocutaneous flap (tubed LDMCF) may be useful for treating circumferential esophageal defects.

METHODS

A segment of esophagus 3 vertebrae long was excised through a right thoracotomy in each of 6 puppies, and a tubed LDMCF was interposed between the cut ends of esophagus. The puppies were sacrificed after a mean follow-up period of 6.6 years. The tubed LDMCF was examined histologically. Functional integrity was assessed using barium meal and endoscopy before sacrifice.

RESULTS

All puppies survived and grew normally on a normal diet, although 4 vomited occasionally. There was smooth passage of barium through the tubed LDMCF without stenosis, although endoscopy showed regrowth of hair. Histologically, no metaplasia, dysplasia, or malignancy was observed in any tubed LDMCF.

CONCLUSIONS

The tubed LDMCF is technically safe, obviates the necessity for laparotomy, and long-term follow-up would suggest that it is histologically stable. Thus, it could become an alternative procedure for bridging esophageal defects.

Intraoperative pancreatoscopy for pancreatic duct stone debris distal to the common channel in choledochal cyst

BACKGROUND/PURPOSE

Pancreatic duct stone debris is a recognised problem in patients with choledochal cyst (CC). The authors present the use of intraoperative pancreatoscopy (IP) in diagnosis and treatment of pancreatic duct stone debris distal to the common channel (distal PDSD).

METHODS

Sixty-seven patients with CC treated over the past 12 years were reviewed retrospectively. Distal PDSD was detected in 8 of these 67 cases (11.9%) using cholangiography. IP of the common channel or pancreatic duct at the time of surgery for CC was performed using a pediatric cystoscope in 7 of these 8 cases.

RESULTS

All 8 patients had a long common channel. All presented with acute pancreatitis. In 7 of these 8 patients, IP was efficient in detecting and for removing distal PDSD by irrigation. In the remaining case associated with annular pancreas, distal PDSD was identified in the proximal pancreatic duct and was removed directly after incision of the pancreatic duct. Postoperative pancreatitis occurred in only 1 case. All patients are well after a mean follow-up period of 7.3 years.

CONCLUSION

Distal PDSD should not be ignored. IP allows direct examination of the pancreatic duct system and facilitates complete removal of distal PDSD, which may be the cause of relapsing pancreatitis or pancreatolithiasis after radical surgery for CC.

Laparoscopic surgery in newborn infants

BACKGROUND

Thanks to various technical innovations and advances in instrumentation, laparoscopic surgical intervention is now possible for certain congenital anomalies in children. To test the applicability of laparoscopic surgery in neonates, we reviewed our personal experience of neonatal laparoscopic surgery, focusing on cardiopulmonary function, surgical procedures, problems with devices, and degree of associated surgical stress.

METHODS

We performed 65 laparoscopic procedures in neonates. Their ages ranged from 2 to 30 days old, and their body weights ranged from 1,980 to 4,780 g. All 65 laparoscopic procedures were carried out without mortality or serious morbidity.

RESULTS

As complications, we encountered four cases of hypothermia due to rapid insufflation of carbon dioxide (CO(2)). We also found that relative hypercapnea (increase in end-tidal CO(2) as high as 61 mmHg) developed unless hyperventilation and a relatively high peak insufflation pressure were maintained during pneumoperitoneum. No cardiac depression developed at this insufflation pressure. Fluid and electrolyte balance during our cases of newborn laparoscopic surgery, as well as the doses and volumes of fluid and electrolytes administered, were identical to those required for open surgery. Interleukin-6 (IL-6) was measured serially to estimate the degree of associated surgical stress and was found to be significantly lower in neonates who had received laparoscopic procedures than in those who had received open procedures.

CONCLUSION

Laparoscopic surgery can be carried out safely even in neonates.

Different types of congenital biliary dilatation in dizygotic twins

A pair of dizygotic twins who were both found to have congenital biliary dilatation, but of different types, is reported. This case is of academic interest from an etiologic point of view.

Laparoscopic extramucosal pyloromyotomy versus open pyloromyotomy for infantile hypertrophic pyloric stenosis: which is better?

BACKGROUND/PURPOSE

The aim of this study was to evaluate the advantages or disadvantages of laparoscopic pyloromyotomy compared with open transumbilical fold pyloromyotomy.

METHODS

Thirty consecutive laparoscopic extramucosal pyloromyotomies (LP) performed from 1994 to 1997 were compared with 30 consecutive open pyloromyotomies (OP) performed during the same period with regard to age at operation, body weight, thickness of hypertrophied pyloric muscle, operating time, time of return to full feeding, frequency of postoperative emesis, surgical complications, and degree of surgical stress reflected by interleukin-6 (IL-6). LP was performed according to conventional techniques, and OP was performed using a transumbilical fold approach.

RESULTS

The groups were matched for age at operation, preoperative clinical and physical status, laboratory data, and size of the hypertrophied pylorus assessed by ultrasonography. There was a learning curve with LP; the average operating time required for the first 10 cases was significantly longer than the time required for OP, but later cases took just as long as OP cases. Time taken to full feeding was significantly shorter in the LP group than the OP group (LP, 38 hours v OP, 64 hours). One case was converted from LP to OP because of mucosal perforation. The incidence of postoperative emesis was significantly higher in the OP group than in the LP group (OP, 25% v LP, 3%). The mean length of hospitalization was significantly shorter in LP (P < .01). The intraoperative peak values of IL-6 in LP were significantly lower than those in the OP group (P < .01).

CONCLUSIONS

The advantages of LP are improved cosmesis, decreased surgical stress with earlier postoperative recovery, and shorter hospitalization. Because LP uses reusable devices, and the mean period of hospitalization is shorter, average operating costs could be reduced, representing a net saving in total hospital charges.

Initial experience with non-breath-hold magnetic resonance cholangiopancreatography: a new noninvasive technique for the diagnosis of choledochal cyst in children

BACKGROUND/PURPOSE

Magnetic resonance cholangiopancreatography (MRCP) is an emerging tool for the noninvasive evaluation of the pancreaticobiliary tree.

METHODS

Non-breath-hold MRCP was used in three children to evaluate choledochal cyst; a first for this new modality of diagnostic imaging. In all cases, the intrahepatic and extrahepatic bile ducts, and the pancreatic duct were clearly visualized.

RESULTS

Two cases were found to have a fusiform choledochal cyst, and non-breath-hold MRCP demonstrated pancreaticobiliary malunion and a long common channel. In the remaining case, the size and location of the huge cyst prevented visualization of any pancreaticobiliary malunion. Endoscopic retrograde cholangiopancreatography (ERCP) in this patient failed to provide any additional information. All patients underwent cyst excision with hepaticoenterostomy, and made an uneventful recovery.

CONCLUSIONS

Our initial experience suggests that non-breath-hold MRCP is a reliable method for the diagnosis of choledochal cyst in children and could replace ERCP.

Pancreaticobiliary maljunction associated with nondilatation or minimal dilatation of the common bile duct in children: diagnosis and treatment

It is known that the etiology of congenital biliary dilatation (CBD) is closely associated with pancreaticobiliary maljunction (PBMJ). Treatment of CBD today is primary excision of the cyst followed by hepaticoenterostomy. However, PBMJ without dilatation of the biliary tract has recently been reported and its treatment is still controversial. In adults, simple cholecystectomy without biliary reconstruction is often performed, because it usually presents as an anomaly of the gallbladder. Over 30 years, we have encountered 8 patients with PBMJ without dilatation of the common bile duct in 180 pediatric cases of CBD. The presenting symptoms of these patients were those of pancreatitis i.e. abdominal pain associated with elevation of serum amylase levels. Five cases presented with jaundice or a history of pale colored stools. Endoscopic retrograde cholangiopancreatography was performed to confirm the diagnosis. Five (62.5%) of these 8 patients were found to have dilatation of the common channel, which was seen in 50 (29%) of the 172 other cases with biliary tract dilatation. Three cases (37.5%) had proven protein plugs or debris at the level of the common channel, and this was observed in 28 (16%) of the 172 other cases. It is strongly suggested that the manifestation of clinical symptoms in these patients results from stasis or obstruction at the level of the common channel. In children who present with recurrent pancreatitis, PBMJ must be suspected even if the common bile duct appears to be normal. It is difficult to resolve these anomalies without operative repair. The authors consider that radical treatment of PBMJ is required in these children to prevent serious long-term complications.

Hepaticoenterostomy after excision of choledochal cyst in children: a 30-year experience with 180 cases

In the long-term follow-up of patients with choledochal cyst, postoperative ascending cholangitis and/or stone formation in the intrahepatic bile ducts (IHBD) owing to anastomotic stricture present serious problems. To prevent the formation of anastomotic strictures, some surgeons recently have performed hepaticoenterostomy at the hepatic hilum, with a wide stoma, in all patients with choledochal cyst. The authors of the present study review the surgical procedures performed on a total of 180 children with choledochal cyst and discuss the treatment of choice, with special reference to the types of hepaticoenterostomy. The medical records and radiographs of all patients treated for choledochal cyst between January 1964 and December 1993 at the authors' institutions were reviewed. A total of 180 patients (mean age at time of surgery, 4.3 years) had follow-up for a mean of 11.1 years; 174 of them had cyst excision and hepaticoenterostomy, and six had cystoenterostomy. Of the 174 patients who underwent cyst excision, 171 had a conventional hepaticoenterostomy; two had an intrahepatic cystoenterostomy, and one had a hepaticoenterostomy at the hepatic hilum. IHBD stones with or without cholangitis developed postoperatively in four (2.3%) of the 171 patients who had conventional hepaticoenterostomy. The age at time hepaticoenterostomy of these four patients was 12, 7, 16, and 6 years. Postoperative IHBD stone formation and cholangitis were not found in 121 patients under 5 years of age. The authors recommend conventional hepaticoenterostomy as the treatment of choice for children with choledochal cyst. Hepaticoenterostomy at the hepatic hilum is indicated in only selected cases.

[Surgical strategy for the treatment of congenital biliary dilatation based on the location of intrahepatic bile duct dilatation]

Congenital biliary dilatation used to be regarded as having a good prognosis. However, some recent long-term follow-up studies have shown there to be quite a high incidence of postoperative intrahepatic bile duct (IHBD) stone formation. In most of the cases in whom IHBD stones form, the IHBD were found to be dilated as the time of initial surgery. Therefore, preoperative evaluation of IHBD dilatation using various imaging studies is extremely important. Surgically, in cases involving structure of the common hepatic duct (CHD) with dilatation above the structure, resection of the stricture and a wide hepaticointestinal anastomosis are strongly recommended. In cases where there is a stricture of the CHD or of the first branch of the IHBD, a reconstructive technique should be applied to dilate the stricture. Patients who have a structure and cystic dilatation of the IHBD above the second branch should be carefully followed-up postoperatively. Partial liver resection to remove the cyst may be required at the time of initial operation or at a later stage.

Laparoscopic bipolar strip-tease appendicectomy. A new endosurgical technique

Since its conception, several techniques have been described for laparoscopic appendicectomy. We describe a technique which utilizes a 5-mm bipolar forceps designed to coagulate and cut tissues at the same time; 50 pediatric patients underwent laparoscopic appendicectomy for acute appendicitis using this "stripping and teasing" technique. No bleeding complications occurred. There were only two postoperative abscesses in the series. We believe that the bipolar laparoscopic striptease appendicectomy technique as developed by the senior author is safe, quick, and effective, even for severe appendicitis.

Tubed latissimus dorsi musculocutaneous flaps for thoracic esophageal replacement: an experimental study

Tubed musculocutaneous flap has never been used to replace a circumferential defect of the thoracic esophagus in adults or children. The aim of this study was to examine whether a tubed latissimus dorsi musculocutaneous flap (TLDMF) can be used to repair a long gap defect of the thoracic esophagus. In 14 puppies with an average weight of 4.9 kg, part of the esophagus (two vertebrae in length) was excised through a right thoracotomy. A latissimus dorsi musculocutaneous flap was introduced into the thoracic cavity. The cutaneous layer was rolled into a tube and interposed in the space of the excised esophagus. The muscle layer was wrapped around the anastomosis. Three puppies died of operative complications, such as a minor anastomotic leakage and postoperative bleeding. One died of an unknown cause. Ten puppies were studied postoperatively with a barium meal, endoscopic examination, and autopsy. The management of these puppies over 4 months is described. It proved possible to replace a long gap thoracic esophageal defect with a TLDMF, which was safe, easy to be transferred, and obviated a laparotomy. Thus, this technique might offer an alternative method to bridge a long gap in patients with esophageal atresia or severe stenosis.

Actin and myosin deposition around bile canaliculi: a predictor of clinical outcome in biliary atresia

The role of pathological changes of the intrahepatic bile canaliculi in determining postportoenterostomy bile drainage in biliary atresia (BA) patients remains unestablished. It is known that canalicular contraction contributes an active force for bile flow in normal ductal systems. This motility is controlled by the bile canalicular membrane-associated filaments (BCMF), particularly actin and myosin. Wedge resected specimens of liver from 13 patients with BA were studied using histopathological markers of BCMF in order to clarify the morphological and functional changes of bile canaliculi. Histopathological data were also compared with clinical outcomes after portoenterostomy. Patients who showed sufficient bile flow after the operation showed an almost normal shape and level of BCMF accumulation around bile canaliculi, whereas there was markedly increased BCMF volume in patients who did not exhibit bile flow after surgery. The clinical staining patterns of BCMF in BA patients appears closely related to clinical outcome. These findings suggest that BCMF plays an important role in determining the rate of postoperative bile flow in BA patients.