Perforated appendicitis: an evidence-based definition

Papers that cause the coveted “ahah!” feeling are very few and far-between. But this one certainly made me go ahah!

In this paper, the authors set out to unify the definition of perforated appendicitis. They pointed out that since the definition of perforation was all over the board, no true conclusions could be made of studies looking at outcome.

The authors defined perforation as the presence of a visible hole in the appendix or the finding of an extruded appendicolith (this definition was used for a prior study they performed). Patients with purulent fluid in the peritoneal cavity who did not have a visible hole as well as patients with a gangrenous appendix were considered non-perforated. Patients in the perforated appendicitis group received a prolonged course of postoperative antibioitcs while those in the non-perforated group received only preoperative antibiotics. The authors then studies the effect of this strict definition on patient outcome, including the rate of intraabdominal abscess formation.

The results were very interesting. Expectedly, the rate of postoperative abscess formation in the perforated group increased from 14% to 18%. This made sense since the denominator in the perforated group was smaller with this strict definition. More importantly, the rate of abscess formation in the non-perforated group decreased, from 1.7% to 0.8%. This was the most important finding in this study. This confirmed that withholding postoperative antibiotics from patients with a gangrenous appendix, or those with “puss” in the abdomen but no true hole, did not result in worse infectious complications.

Defining perforation in clear simple terms, and showing that this definition works, should help prevent unnecessary antibiotic administration, waste of resources, as well as inter-study inconsistencies.

St Peter et al. An evidence-based definition for perforated appendicitis derived from a prospective randomized trial. J Ped Surg (2008) 43:2242-45

Rotational anomalies of the midgut... what's what?

At least once a year, a funny looking UGI study sparks the traditional discussion on rotational anomalies of the GI tract. And the fact that radiologists and surgeons don't necessarily agree on the terms used to describe different types of rotational anomalies doesn't help. Assuming radiologic findings reflect intra-operative findings (and this is assuming with a capital "A"), the following classification is helpful.

Rotational anomalies refers to situations where normal 270 degree counter-clockwise rotation and subsequent fixation of the bowel between the 5th to 10th week of gestation is not completed. Normal rotation results in a wide mesenteric base, which protects the bowel from volvulus (Fig 1. Red line). The most important implication of rotational anomalies is that they result in a spectrum of abnormal mesenteric base lengths, and subsequently variable risks for midgut volvulus. Based on the radiologic literature, the two main types of intestinal rotational anomalies are incomplete rotation and non-rotation.

In the case of incomplete rotation, the most common type, the proximal and distal midgut both rotate between 90 and 180 degrees. This places both the duodeno-jejunal junction (DJJ) and the cecum in close proximity to each other, and thus results in a narrow mesenteric base, prone to volvulus (Fig 2).

The second most common type of rotational anomaly is intestinal non-rotation. In this form, there is minimal rotation (<90 degrees) of both the proximal and distal midgut. This keeps the proximal mesenteric attachment (DJJ) and the distal attachment (cecum) far enough from each other that the risk of volvulus is much lower than that with incomplete rotation.

Although this is a useful classification, it is important to always keep in mind that radiologic findings do not necessarily always reflect true anatomy, and the potential for false positive and negative findings on UGI exist.

Shew S B. Surgical concerns in malrotation and midgut volvulus. Pediatric Radiology (2009); 39:S167-181

My take-home summary of PS233 : To tweet or become extinct?: why surgeons need to understand social networking

The panel discussion started at 230 pm with an enthusiastic crowd and a very welcomed skepticism from a few of the attendants. I say welcomed because such skepticism is critical in keeping a check on how we use social media. Patients are NOT our friends (thank you @jcparamo), but they can be fans of your practice’s FB page, which can be configured to work like a read-only “yellow page” (via @Z1G1).

Dr Philip Glick kicked off the discussion by encouraging the audience to sign up on Twitter and engage the panel through a live Twitter feed (which I’m very pleased to say, many did). Someone even coined the term “loss of Twitter virginity” at the session!
Dr Glick then showed some statistics that reflect the use of social media by members of the American College of Surgeons (ACS). Only one third of ACS members participate in online forums or read online health blogs, which are a major player in patient education. If patients go to health blogs and forums for information, and we are not participating in them, WHO is giving them information?

Zach Glick then proceeded to give the audience an introduction to Twitter, including how to set up the account and “tweak” security setting. Always remember to look for boxes checked by default and uncheck them as necessary! Zach’s section helped audience members sign up on Twitter there and then and experience it’s capacity to spread and exchange information instantaneously by transmitting their tweeted comments and criticisms to a live Twitter feed projected on a screen in the room.

In my section I discussed the use of Twitter in the spread and exchange of information. Twitter’s reputation as a social gimmick has given it a “bad rap”, to the extent that it is difficult to get other surgeons to even listen to the argument for its use. Fortunately, Twitter has become more of a tool used to spread and exchange information than a way to keep up with your friends’ minute to minute activity. When a group of surgeons of similar interest are linked through Twitter, they can exchange pertinent information they find on the web (whether it’s a great YouTube video, or a blog that can help with patient education, or an excellent paper) by sending out a brief tweet with a link (shortened URL) to that source.

Twitter can help surgeons sift through the mass of information on the internet, share what’s relevant, and enrich it with their own thoughts and experiences.

Sussanah Fox (our social media guru!), discussed the different levels of participation in social media, from “lurking” and simply listening-in on what others have to say, to sharing interesting findings with others, to actually creating and contributing to online content. I found this section particularly interesting, given that several of the surgeons in the audience voiced their concern about tweeting and blogging “on a daily basis”. We do not all have to contribute to these resources, but they are there for us to use and experience. We do not have to jump into the deep end right away (via @SusannahFox). I think surgeons should start with simply searching for blogs and forums that discuss medical education (blogs.usask.ca/medical_education), surgical issues (forsurgeons.net), and provide patients with information (preop.com) to get an idea of what’s “out there”. Some may proceed to share and create, others may just keep listening. But I truly believe that we have to, at least, listen.

Rebekah Monson, as Susannah put it, made us all feel appropriately apprehensive about social media. Her contribution was central to bringing home the point that social media, when integrated into our professional, and personal lives for that matter, must be handled with care and reason. She also brought the point home by pointing out that employers hire and fire based on the contents of social media.

Dr Scott Lind wrapped up the session by giving examples of how social media can be incorporated into a practice, sighting how the Georgia Society of the American College of Surgeons has created a mobile app! He also discussed the issue of how surgeons are perceived as arrogant and aloof, based on a patient survey, and how the use of social media can help fight that perception.

The session ended with some very relevant question by the audience, including some very legitimate concerned voiced.

Overall I learned a lot from this panel discussion and particularly from the audience’s reaction and participation. Surgeons seem to be very interested in social media, but have legitimate concerns about ramifications.

ACS congress news report at:
http://www.facs.org/clincon2010/press/thurs.pdf

Bulletin of American College of Surgeons article:
http://www.facs.org/fellows_info/bulletin/2011/peregrin0211.pdf

How often is a surgical process the cause of bilious emesis in a newborn?

Pediatric surgeons are trained to recognize bilious (green) emesis as a "red flag" that necessitates immediate attention to evaluate for surgical causes, specifically malrotation with midgut volvulus.

Godbole et al evaluated the outcome of 63 neonates with bilious emesis over a two-year period and noted that 38% had a surgical cause. Nine had Hirschsprung's disease, 5 had small bowel atresia, 4 had intestinal malrotation, 3 had meconium ileus, and one each had meconium plug, colonic atresia, and milk inspissation.

Importantly, one of the four neonates with malrotation had no abdominal signs or symptoms, as well as a normal abdominal radiograph at time of diagnosis. On the other hand, the majority of neonates with non-surgical causes had a normal exam and abdominal radiographs. .

Non surgical causes for bilious emesis were thought to mostly represent gastro-esophageal reflux and gastric dysmotility, metabolic disturbances, and/or sepsis.

All patients with bilious emesis need a thorough abdominal exam and an abdominal radiograph. Although a relatively small number of these patients (4/63) will have malrotation with potential midgut volvulus, a prompt evaluation with an UGI should always be considered given the potential catastrophic consequences of a missed midgut volvulus.

Godbole P, Stringer MD. Bilious vomiting in the newborn: how often is it pathologic? J Pediatr Surg 2002;37:909-911

Are bowel preps really necessary before abdominal operations in children?

It’s 11pm, and a 12 YO girl is sitting teary-eyed with a tube hanging form her nose. She tried her best to drink that “stuff” but finally gave up and asked for the naso-gastric tube so she can get her bowel prep. Why is she getting her bowel prep? well, apparently, someone in the 1970’s thought it was a good idea!

The current data on the need for bowel preparations before elective colorectal surgery in the adult literature overwhelmingly contradicts the dogma that a bowel preparation is necessary for a safe operation, with a decreased risk of anastomotic leak and wound infection.

Recently, a pilot study by Leys et al, from Vanderbilt University Medical Center, showed findings in the pediatric population consistent with those in the adult literature. The study, which was retrospective in nature, compared the outcomes between 33 patients who did not undergo a bowel prep (No Prep) and 110 who did (Prep).

The study results showed that, despite the Prep group receiving postoperative antibiotics for a longer duration than the No Prep group, as well as greater incidence of delayed wound closure, the two groups did not have any significant difference in anastomotic leaks or wound infection rates.

The rationale behind bowel preps is that they decrease the fecal and bacterial load inside the lumen of the bowel, and thus decrease the risk of infectious complications. Some studies, which have found an increased risk of infectious complications with patients undergoing bowel preps, theorize that the liquid bowel content that results from the bowel prep is more difficult to manage, spills more easily and thus may explain the increased risk of infectious complications.

Despite the retrospective nature of this study by Leys et al, one cannot help but suspect that the results of the research in the adult literature should apply to this younger and generally healthier patient population. Obviously, and before any recommendations can be made about the need to omit bowel preps, a multi-center randomized prospective study with sufficient patients is needed.

Leys C M, Austin M T, Pietsch J B, Lovvorn H N, Pietsch J B. Elective intestinal operations in infants and children without mechanical bowel preparations; A pilot study. J Pediatr Surg 2001;40:978-82

Avoiding placement of implanted central venous catheters in neutropenic patients decreases complication rates

The authors of this study evaluated the outcome of the implementation of a protocol that restricts the placement of implanted central venous catheters to patients with an ANC greater or equal to 500. This was based on previous findings that suggested that placement of implantable central venous devices in neutropenic patients is associated with higher rate of complications.

The authors found a higher rate of complications (infectious and technical) in neutropenic patients. Additionally, the rate of these complications was substantially decreased after implementation of a protocol that excludes neutropenic from device placement.

Gollin G, Gutierrez I. Exclusion of neutropenic children form implanted central venous catheter placement: impact on early catheter removal. J Pediatr Surg 2010;45:1115-1119

Cryptorchidism and testicular cancer

Prevalence of undescended testicles (UDT) is 3-4% at birth. The rate of UDT drops to 1% at 12 months, given that 2/3 of UDT demonstrate descent by age 3 months. The rate of UDT is higher in preterm infants, with no increased risk of malignancy in testes that descend spontaneously in the first 3-12 months. Infants (term or preterm) should be allowed to reach an adjusted gestational age of 12 months before orchidopexy is performed.

Using a meta analysis of current literature, the authors set out to answer 5 questions regarding cryptorchidism:

1. What is the RR of testicular cancer in a cryptorchid or formerly cryptorchid testis?

The historically quoted increased risk for testicular cancer (RR = 48) considered a substantial overestimate. The true RR for testicular cancer was found to be 4-6 in the undescended testes.

2. What is the relative risk for malignancy in the contralateral, normally descended testis?

Historically, it was believed that the contralateral, normal testis has a 5-10% chance of malignancy. Based on current literature, the authors identified no increased risk for malignancy in the contralateral testis.

3. Does relocating the testis affect the type of testicular cancer

Uncorrected cryptorchidism carries a higher risk for seminoma, while a corrected conditions carries a higher risk for non-seminomatous malignancies.

4. Does orchidopexy decrease the risk of malignancy

Relative risk of testicular cancer in the undescended testicle after operative correction depends on patient age at time of orchidopexy. When performed before the age of 10-12 years, the RR of testicular cancer is between 2 and 3. When orchidopexy is performed after age of 12, the RR is 2-6 times that of patients who undergo surgery before age 10-12 (this is comparable to the risk in uncorrected UDT).

5. Is there a risk of malignant degeneration in testicular remnants?

The risk of malignant degeneration from atrophic testes, resulting from perinatal spermatic cord torsion, is minimal.



Reference: Cryptorchidism and testicular cancer: Separating fact from fiction. Wood MW, Elder JS. Journal of Urology (2009);181:452-61