Use of magnets in pediatric surgery

Since the 1970s, magnets have been progressively harnessed for use in minimally invasive treatment of pediatric surgical disease. In particular, multiple magnetic devices have been developed for treating esophageal atresia, pectus excavatum and scoliosis. These devices, which can be placed via small incisions or under endoscopic or fluoroscopic guidance, provide the added benefit of sparing patients multiple large, invasive procedures, and allowing for gradual correction of congenital anomalies over days to months, depending on the disease. In the following text, we detail the current landscape of magnetic devices used by pediatric surgeons, illustrate their use through clinical cases, and review the available body of literature with respect their outcomes and complications.

Magnamosis for long gap esophageal atresia: Minimally invasive "fatal attraction"

BACKGROUND

Aim of study is to report our preliminary experience with magnetic anastomosis (magnamosis) treating long-gap esophageal atresia (LGEA), the most challenging condition of esophageal atresia continuum. Magnamosis has been reported in 20 patients worldwide as an innovative and marginally invasive option.

METHODS

Prospective evaluation of all LGEA patients treated with magnamosis was performed (study registration number: 2535/2021). Main outcomes considered were demographic and surgical features, postoperative complications and feeding within 6-month of follow-up.

RESULTS

Between June 2020 and January 2021, 5 LGEA patients (Type A, Gross classification) were treated. Median preoperative gap was 5 vertebral bodies. Magnetic bullets were placed at an average age of 81 days of life, leading to successful magnamosis in all cases: 4 infants had primary magnetic repair (one after thoracoscopic mobilization of the pouches), 1 patient had a delayed magnamosis after Foker's procedure. Esophageal anastomosis was achieved after an average of 8 days. No anastomotic leak was found. All patients developed anastomotic stenosis at 6-month follow-up, requiring a mean of 6 dilations each. Full oral feeding was achieved in 3 patients, while 2 were still on oral-gastrostomy feeding. One patient experienced small esophageal perforation after dilation (3 months after magnamosis), distal to the anastomotic stricture and subsequently developed oral aversion.

CONCLUSIONS

Our preliminary results suggest magnamosis a safe and effective minimally invasive option in patients with LGEA. Absence of postoperative esophageal leaks may represent a major advantage of magnamosis over conventional surgery, although possible high rate of esophageal stenosis should be further evaluated.

LEVELS OF EVIDENCE

IV (Case series with no comparison group).

Magnetic cholecysto-duodenal anastomosis

INTRODUCTION

There is a growing interest in minimally invasive endoscopic gallbladder drainage therapies. Unlike stenting, a technology based on magnetic compression could theoretically produce a durable drainage anastomosis without residual foreign material. This study aimed to evaluate the safety and technical feasibility of a cholecysto-duodenal magnetic compression anastomosis.

MATERIAL AND METHODS

We performed a survival study of two Yorkshire pigs. Duodenal magnets were deployed endoscopically; reciprocal gallbladder magnets were placed laparoscopically, and the magnets were coupled. Pigs underwent serial endoscopy documenting magnet expulsion and evolution of cholecysto-duodenal anastomosis creation. Necropsies and histological evaluation were performed. Primary endpoints were technical success and safety. Secondary endpoints included anastomosis integrity, patency, and histologic characteristics.

RESULTS

Magnets were successfully delivered and coupled. Patent, leak-free anastomoses formed by day 4. Magnets were expelled by day 10. All anastomoses were widely patent at one month (mean diameter 15 mm). Necropsy showed the absence of adhesions affecting the anastomosis. Histology showed complete re-epithelialization without inflammation or foreign body reaction.

CONCLUSIONS

Magnetic cholecysto-duodenal anastomosis for gallbladder drainage appears safe and feasible in the animal model. The anastomoses are patent, leak-free, and without inflammation from the presence of foreign material. Technical modifications for magnet delivery under endoscopic ultrasound (EUS) guidance are currently underway.

Laparoscopic Magnetic Compression Biliojejunostomy: A Preliminary Clinical Study

BACKGROUND

Magnetic compression anastomosis is a feasible and effective method for bilioenteric anastomosis (BEA) in animal model. The objective of the present study was to report our initial clinical experience in laparoscopically magnetic compression bilioenteric anastomosis (LMC-BEA).

METHODS

Patients with obstructive jaundice who were candidates for LMC-BEA were prospectively enrolled from 2013 to 2015. All the procedures were performed laparoscopically. A mother magnet and drainage tube were placed in the proximal bile duct and tightened by a purse suture after dissection of the common bile duct. The drainage tube was introduced into the jejunal lumen at the anastomotic site and guided a daughter magnet to approximate the mother magnet. The two magnets mated at the anastomotic site. All the patients were routinely followed up for magnets discharge till the end of the study.

RESULTS

In total, four patients with malignant obstructive jaundice and one patient with benign biliary stricture were included. The median age was 70 y (range, 49-74 y). The median time for LMC-BEA was 12 min (range, 8-15 min). A complete anastomosis was confirmed after a median time of 21 d (range, 5-25 d) postoperatively by cholangiography via drainage tube. The magnets were expulsed around 41 d after surgery (range, 12-47 d) postoperatively. With a median follow-up of 313 d (range, 223-1042 d), no complications associated with magnetic anastomosis was documented, such as bile leakage or anastomotic stricture.

CONCLUSIONS

Magnetic compression is a promising alternate method for laparoscopic BEA. Among the five patients undergoing LMC-BEA, no one developed anastomotic complications.

Minimally invasive entero-enteral dual-path bypass using self-assembling magnets. Surg Endosc. 2016;30:4533-4538. [PMID: 26895911 DOI: 10.1007/s00464-016-4789-x]

BACKGROUND

A minimally invasive method of entero-enteral bypass may be desirable for treatment of obstruction, obesity, or metabolic syndrome. We have developed a technology based on miniature self-assembling magnets which create large-caliber anastomoses (incisionless anastomosis system or IAS). The aim of this study was to assess (a) procedural characteristics of IAS deployment and (b) long-term integrity and patency of the resulting jejuno-ileal dual-path bypass.

METHODS

Endoscopic jejuno-ileal bypass creation using IAS magnets was performed in 8 Yorkshire pigs survived 3 months.

PROCEDURE

The jejunal magnet was endoscopically deployed. However, the ileal magnet required surgical delivery given restraints of porcine anatomy. A 5-mm enterotomy was created through which the ileal magnet was inserted using a modified laparoscopic delivery tool. Magnets were manually coupled. Pigs underwent serial endoscopies for anastomosis assessment. Three-month necropsies were performed, followed by pressure testing of anastomoses and histological analysis.

RESULTS

Jejuno-ileal bypass creation using self-assembling IAS magnets was successful in all 8 pigs (100 %). Patent, leak-free bypasses formed in all animals by day 10. All IAS magnets were expelled by day 12. Anastomoses were widely patent at 3 months, with mean maximal diameter of 30 mm. At necropsy, adhesions were minimal. Pressure testing confirmed superior integrity of anastomotic tissue. Histology showed full epithelialization across the anastomosis with no evidence of submucosal fibrosis or inflammation.

CONCLUSIONS

Entero-enteral bypass using self-assembling IAS magnets is safe and technically feasible in the porcine model. IAS magnets can be rapidly delivered endoscopically or through a modified laparoscopic device. Expulsion of fused magnets avoids retention of prosthetic material. Anastomoses are widely patent and fully re-epithelialized. Three-month pressure testing reveals anastomotic tissue to be as robust as native tissue, while necropsy and histology suggests minimal/absent tissue inflammation. In human anatomy, a fully endoscopic jejuno-ileal bypass using IAS magnets may be feasible.