Encephalitis associated with ovarian tumors

It is one thing to learn something new every day, but another to come across something you have never heard of.

Enter anti-NMDAR encephalitis secondary to ovarian teratomas.

Anti-NMDAR encephalitis syndrome is a constellation of psychiatric symptoms, memory changes, altered level of consciousness, and/or central hypoventilation due to the interaction of antibodies to NMDAR (receptor in brain tissue) with the hippocampus.

This condition can present at any age group, and can be associated with teratomas (in 50% of females above 12 years of age with anti NMDAR encephalitis); mainly the ovarian type.  It is the second most common type of autoimmune encephalitis, and is believed to be the result of interaction of auto antibodies to NMDAR (generated in response to ectopic neuronal tissue in the teratoma) with the hippocampus.  The diagnosis is confirmed with anti-NMDAR antibodies in the blood or CSF.

The treatment for this condition consists of immune therapy (steroids/plasmapharesis/IV immunoglobulin), tumor resection, and possible need for immune suppression.

80% of patient have substantial improvement of symptoms within 24 months of initiation of therapy.  During this time, the risk of relapse is 12%.

News to me.

Reference:

Tiltulaer et al.  Treatment and prognostic factors for long-term outcome in patients with anti-NMDA receptor encephalitis Lancet Neurol (2013) 12:2-157

How effective is bracing in the management of pectus carinatum?

A recent conversation on bracing for pectus carinatum prompted a review of what’s new in the literature.

The principle of bracing relies on the application of constant (23 hours a day) external pressure to a carinatum deformity using a specially made padded brace.  The brace pressure is adjusted to the maximum tolerated by the patient and then left in place until the deformity resolves (corrective phase).  At that point, the patient goes into the maintenance phase, where he/she wears the brace for 8 hours a day until the end of the growth spurt.

In the current issue of JPS, Lee et al. looked at the outcome of bracing for pectus carinatum in terms of average time for the corrective and maintenance phases, compliance, and final outcome.  They noted that, overall, the corrective phase lasted 7±7.3 months. The corrective phase was shorter (4.2±0.9 months) in kids who had not reached Tanner stage IV of maturity when compared to those who had (8.0±7.1 months); a statistically significant difference.

Interestingly, 45% of their patients were considered treatment failures, mainly because of loss to follow up (29%) or non-compliance (15%).

The authors commented on the issue of compliance, suggesting that the fact that results can be noted in as little as a month after brace application encourages patients to accept increasing pressures and improves compliance. However, more work is needed in researching causes of poor compliance and ways to improve it.

Reference:

Lee RT et al. Bracing is an effective therapy for pectus excavatum: interim results. JPS (2013) 48(1):184-90

What is the chance that asymptomatic GB stones in kids will cause problems in the future?

As I prepared to see a kiddo in the office for asymptomatic gall stones, I decided to do a quick review of the literature to see what's new.

Not surprisingly, couldn't find any good studies that looked at the outcome of this patient population.  The best paper I found was by Bogue et al, who retrospectively reviewed charts of 382 patients with GB stones and identified a group of patients who were incidentally found to have cholelithiasis (asymptomatic).  Of the 382 patients, 50% were asymptomatic.  Their mean age was 8 YO, and they had their u/s for unrelated causes, manly other abdominal pathology.

The authors reported that follow up for these asymptomatic kids was "an annual clinical and ultrasound assessment for 1 to 2 years" unless they had other pathology that necessitated longer follow up.  With this strategy, their mean follow up for this patient group was 3+/- 1.7 years.  During this follow up period, only 4.6% of the patients developed complications related to their stones (pancreatitis, choledocholithiasis, cholecystitis). Interestingly, they noted that 19% of GB stones eventually resolved, as demonstrated by follow up ultrasounds (when they were done).

So what does this mean?  Not much when it comes to counseling parents.  At best I can suggest to them that there is very little chance the stones will cause problems in the near future, but that we can not predict their behavior (or even their persistent existence) over the long run.

Reference:
Bogue C O et al.  Risk factors, complications, and outcomes of gallstones in children: a single-center review. Journal of Pediatric Gastroenterology and Nutrition (2010) 50:p303

What is the fate of abnormal looking bowel seen on prenatal ultrasound?

While reviewing the literature on prenatal imaging and their prognostic implications, I came across this relevant article by Ruiz et al from Morgan Stanley Children's Hospital.

The authors looked to study the relationship between abnormal prenatal ultrasound findings in the bowel and the presence of an actual bowel abnormality at birth.  They divided patients into two groups, those with hyperechogenic bowel and those with dilated bowel.

Of the fetuses with a finding of hyperechogenic bowel, the authors noted a 20% rate of prenatal demise.  Otherwise, only 10% of those patients were born with abnormal bowel (usually from meconium disease).  During follow up prenatal ultrasound studies, 65% of the findings resolved in that group of patients.

The group with the dilated bowel on u/s had a higher chance of having a true bowel abnormality when born.  Although the rate of prenatal demise in that group was lower (10%), fetuses with dilated loops of bowel on prenatal u/s had a 53% chance of being born with abnormal bowel (usually from intestinal atresia).  On follow up prenatal ultrasound studies, only 20% of the findings resolved in that group of patients.

This data sheds some light on the significance of bowel abnormalities found on prenatal ultrasounds, and thus helps better counsel parents on what to expect.

Reference:

Ruiz JR et al.  Neonatal outcomes associated with intestinal abnormalities diagnosed by fetal ultrasound.  Journal of Pediatric Surgery (2009) 44,71

What is the most common type of vascular rings in children?

The basic back bones of the development of the vascular system are the dorsal aortae and ventral roots, and 6 aortic arches that join the two, on the right and left.

Regression of some of the arches in central to the normal development of the vascular system.
Only the 3rd, 4th, and part of the 6th arches should persist to contribute to the carotid arteries, right subclavian/aortic arch, and the pulmonary arteries, respectively (figure).

The most common vascular ring (1% of population) results from a right subclavian artery that takes off from the arch of the aorta on the left, due to abnormal regression of the right 4th arch. The subclavian artery passes behind the esophagus.  This type of incomplete vascular ring rarely causes symptoms in children, and surgical therapy, if needed, consists of division of the vessel through a left thoracotomy.

Reference:
Pediatric Surgery.  Coran A. 7th edition

Staging ovarian masses intra op... what are we responsible for as pediatric surgeons?

Managing ovarian masses in children can be quite challenging. This is more of a decision making challenge than a technical one.

The fact that we usually have little information preop that is useful in helping to risk stratify a lesion and answer the question 'is this malignant or not' makes many of the decisions we make difficult: Laparoscopic or open resection? shall we try to save any remnant ovarian tissue or do a complete oopherectomy?...

Occasionally some intraoperative findings guide that decision, but more frequently we are faced with an ovarian mass, normal preop AFP/BHCG (whatever the diagnostic implications of those are), and no evidence of local or distant spread.

Regardless of different approaches to that scenario, one thing we are responsible to do as surgeons is clearly document intraoperative findings (including pertinent negatives) so that the information is available if the mass does turn out to be malignant.

Per COG recommendations, intraoperative documentation of the following should be made (including pertinent negatives)

1. Collection of ascites or washings on entering the peritoneum

2. Examination of peritoneal surface with biopsy of any nodules

3. Examination and palpation of retroperitoneal LN's and biopsy of firm or enlarged ones

4. Inspection and palpation of the omentum with excision of any abnormal or adherent areas

5. Inspection and palpation of the contralateral ovary and biopsy any abnormal areas

6. Complete resection of the tumor and ovary with sparing of the fallopian tubes if not involved.

Clearly, if a totally laparoscopic approach is used, palpation of the peritoneal lining and omental lesions is not possible, which makes it impossible to perform the complete staging mentioned. In some situations, however, the contralateral ovary and retroperitoneal lymph nodes may still be palpated if a small Pfannenstiel incision is used to extract the ovarian mass.

Reference:
Oltmann S et al. Pediatric ovarian malignancies: how efficacious are current staging practices? JPS(2010)45,1096-1102

Do we need to administer antibiotics before enema reduction of intussusception?

When reading the chapter on intussusception in Grosfeld's Pediatric Surgery, I noticed that the authors recommended that antibiotics be administered to patients before attempts at air enema reduction. No good explanation was given for this practice, which we do not follow where I train. Patients go for their enema reduction, and if that fails, get preoperative antibiotics at the time of surgery, just like everyone else.

 

An article the May issue of JPS attempted to answer the question of the benefit of pre-contrast enema reduction antibiotics. The authors performed a retrospective, cohort study comparing outcome of patients form two different institutions; one that routinely gives pre-reduction antibiotics and one that does not.

 

The main end-points of this study were the incidence of post-reduction fever (as a marker of bacteremia) as well as adverse reactions to antibiotic administration. The authors noted no significant difference in either, suggesting (despite the usual shortcomings of a retrospective study) that antibiotics are not necessary.

 

Although it would take a prospective randomized study to better answer this question, it does not seem to make sense to give antibiotics before enema reduction.

 

Reference: Al-Tokhais et al. Antibiotics administration before enema reduction of intussusception: is it necessary? JPS (2012);47:928