Saturday, April 29, 2017

Phocomelia

Phocomelia is defined as 'seal limb'- a birth anomaly (i.e., congenital malformation) in which the hands are essentially attached to the chest.  There may be a short bone connecting the hands to the chest, either a forearm bone or arm bone, but not both.  Phocomelia is incredibly rare and really became a recognized abnormality in relation the the thalidomide epidemic in the late 1950s and early 1960s.  Thalidomide was approved for use (actually without even a prescription in Germany) as it had proven safe in animal experiments.  It was used for morning sickness and nausea in pregnant women, especially in the first trimester (which happens to be when the limbs develop and form). There was an explosion of cases of phocomelia in both Europe and Australia  and Canada (rare in the USA as the drug was never approved for use).  Thankfully, the source of the increased incidence of phocomelia was identified and the drug was removed from use (it has recently been used for nausea in chemotherapy for those without a chance of being pregnant).  There have been notable books and articles on this terrible epidemic.  50 years after the epidemic, the drug manufacturer, Grunenthal, finally apologized.

Dark Remedy: outstanding book exploring the thalidomide- phocomelia epidemic.
Specifically defined, phocomelia means a segmental deficiency of the extremity, typically an absence of the either the arm or forearm segment.  But, it is important to remember that the segments that are present, including the hand, are never normal.  In 2005, we shared the St. Louis and Dallas experience around patients diagnosed with phocomelia.  We examined the extensive patient experience at three busy hospitals: Texas Scottish Rite, St. Louis Shriners Hospital, and St. Louis Childrens Hospital to assess all patients with a diagnosis of phocomelia.  We learned that most of the kids so diagnosed really had either a severe form of radial longitudinal deficiency More information on RLD or ulnar longitudinal deficiency More information on ULD and NOT phocomelia.  We established and defined the Type 5 radial and ulnar deficiency in the manuscript describing our findings:  Manuscript Link  There were some kids in our large group that could not be labeled as radial or ulnar longitudinal deficiency- those were kids more likely to have the segmental deficiency of phocomelia.

So while most kids that appear to have phocomelia really have either a radial or ulnar longitudinal deficiency, some will truly have a segmental defect as phocomelia.  Typically this is likely a spontaneous mutation or birth defect but there are some inherited patterns such as Roberts Syndrome, among others listed at OMIM- OMIM syndrome list.

I am grateful that the family of this child agreed to allow us to post pictures and x-rays to demonstrate the appearance of phocomelia.

Patient with phocomelia.  Note the limited hand development.

Patient with phocomelia.  Note the limited hand development.

X-ray of phocomelia patient.  There are several fingers and a short bone attaching to the chest.

Patients with phocomelia have functional challenges primarily because the limbs are short.  Getting the hands to the mouth and using the toilet are tough due to the length of the arms.  This patient has normal lower extremities and some kids will chose to use their feet for functional activities including writing and eating.  We absolutely support this type of functional activity and sometimes have to encourage schools to be supportive of this as well.  In addition, there are therapy tools and tricks which can help with all sorts of daily activities to make life easier.  Finally, surgery is only very rarely indicated and is typically focused on either stabilizing digits or lengthening the bones that are present.

Charles A. Goldfarb, MD
My Publication List
congenitalhand@wudosis.wustl.edu

Sunday, April 2, 2017

Anesthesia- Do we know the risk in a child?

Recently, there has been much discussion regarding anesthesia in the child.  The concern is appropriately about safety- do we know when it is 'safe' to allow anesthesia for children.  There have been a large number of studies on this topic and recently the FDA voiced concerns.  I will try to summarize the issues and our understanding (at least the understanding of an informed surgeon).

1) Anesthesia has more risk in children compared to adults.  There are many reasons for this including simple concepts such as the small size of the windpipe in the very young child.  Cardiac events and even death are risks in any anesthesia and these are higher in young children- however, remember that anesthesia is very, very safe but the risks are somewhat higher in young children compared to adults.

2) One of the concerns is the risk of learning delays or 'cognitive' difficulties for children that have surgery at a young age.  This is very difficult to study for some obvious reasons including only young children with serious issues have major or repeated surgeries at a young age.  There really is very limited know risk to simple, short surgeries such as ear tubes or short orthopedic surgeries.  A very good study was published from Sweden on this topic.

This study showed very minimal differences in academic performance based on exposure to anesthesia and it showed things like maternal education and season of birth (i.e., winter vs summer) had an even bigger effect.  Other studies, such as the 'PANDA' and the 'GAS' study did not find evidence for an association with single brief exposures to anesthesia.

3) The anesthesia provider matters.  I have blogged previously that I believe experience matters in the care of your child.  An experienced surgeon is, I strongly believe, better able to give your child the care he/ she needs for the best possible outcome.  The literature also strongly supports that the anesthesia team matters to the safety of your child.  A busy children's hospital is a safer place for surgery than the anesthesia provided by those who only occasionally take care of kids.  One study showed a risk of 7 complications/ 1000 surgeries for an anesthesia team that performed less than 100 surgeries a year compared to 1.3 complications/ 1000 surgeries for teams that performed more than 200 surgeries/ year.

The FDA recently provided some thoughts.  The link to the entire statement is provided HERE.   The first two paragraphs are key:

The U.S. Food and Drug Administration (FDA) is warning that repeated or lengthy use of general anesthetic and sedation drugs during surgeries or procedures in children younger than 3 years or in pregnant women during their third trimester may affect the development of children’s brains.

Consistent with animal studies, recent human studies suggest that a single, relatively short exposure to general anesthetic and sedation drugs in infants or toddlers is unlikely to have negative effects on behavior or learning. However, further research is needed to fully characterize how early life anesthetic exposure affects children’s brain development.

Additionally there are two websites that have received publicity.
1. Smarttots.org Link  This site discusses some of the ongoing research
2. Safetots.org Link  This site discusses some of the general concepts I have shared and the importance of an experienced pediatric anesthesiologist.

The bottom line is that we should carefully consider anesthesia in anyone, especially a young child.  Lengthy and repeated surgeries may carry some risk and anesthesia by non pediatric providers does have some risk.  Every decision for surgery is a serious one.  However, after reviewing the literature, I feel that surgeries for problems that are affecting a child's hand or arm (typically shorter surgeries and unlikely to require second surgeries in a short interval) have very low risk in the appropriate hands.

Charles A. Goldfarb, MD
My Publication List
congenitalhand@wudosis.wustl.edu