Thursday, October 2, 2014

1.7 cm carcinoid in the appendectomy specimen, now what?

I have yet to walk away from a conversation about the management of incidentally found carcinoid tumors of the appendix satisfied.  Today, I was determined to find some kind of an answer.

My basic understanding is that an incidentally found lesion which is < 2 cm and with negative margins is essentially treated with the appendectomy.  Otherwise, a hemicolectomy is needed.

If we were to extrapolate form the adult literature, the simplest recommendation is that of the NCCN version 2.2014 (National Comprehensive Cancer Network). Simply stated, a tumor < or = 2cm completely removed with the specimen is essentially cured with no further operative management needed.  Surveillance is performed "as clinically indicated". The document does acknowledge the fact that the management of tumors between 1 and 2 cm with poor prognostic factors such as mesoappendiceal invasion, lymphovascular invasion, or atypical histologic features, is controversial.

The NANETS (North American Neuro Endocrine Tumor Society) guidelines officially take into account local invasion.  They recommend right hemicolectomy for patients with evidence of tumor invasion to the base of the appendix, if the tumor is >  2 cm, if tumor size cannot be determined, if tumor is incompletely resected, if there is lymphovascular invasion or invasion of the mesoappendix, in patients with intermediate or high grade tumors, and in patients with mixed histology tumors.

A recent paper, Kim et al reported their experience with the management of incidentally found carcinoid tumors. The authors noted that out of their 13 cases, only one tumor was larger than 2 cm (2.1 cm) and that was the only patient, out of three who had a right hemicolectomy, who was found to have regional metastatic disease.

As is the overall case with carcinoid of the appendix, the numbers are just too small to make solid recommendations, especially for tumors in the 1 to 2 cm range. A good conversation with the patient and family about the numbers and management options is central to decision making.

So much for finding an answer today.




Thursday, July 24, 2014

Metal allergies and the Nuss bar

At least it was not a wound infection, but now what?

Patients who have a previously unrecognized allergy to metal and undergo a Nuss repair with a stainless steel bar can present with a picture of wound infection after bar placement.  Although not as detrimental as a wound infection, metal allergies are not to be taken lightly.

Contact dermatitis from the Nuss bar is a type IV delayed hypersensitivity reaction that occurs in response to one of the components of stainless steel, usually Zinc or Chromium.  The reaction can range from mild with localized dermatitis, to a more systemic inflammatory response.  Patients occasionally simply present with chronic fatigue.

Preoperative screening for metal allergies should include inquiry about personal or family history of metal allergies (specifically ask for problems with metal touches the skin, not just "does anyone in the family have metal allergies").  Even in the absence of a history of atopy, some recommend screening all patients with a patch test that identifies such allergies (T.R.U.E test or AllergEAZE).

In a recent study by Shah et al, the authors recommended testing all patients preoperatively, regardless of family or personal history of allergy, as they recognized a higher incidence of metal allergy (6.4%) than previously reported (2.2%).

Once metal allergy is identified, patients can be treated with a course of steroids, and removal of the bar can be avoided in most cases.


Tuesday, April 29, 2014

Neutropenic colitis gems

From memory:
  1. Neutropenic colitis occurs in neutropenic patients
  2. Mimics appendicitis (trap!)
  3. Don't call it typhlitis, as it falsely suggest that it can only occur in the cecum
  4. A concomitant C diff infection worsens prognosis 
  5. Broad spectrum antibiotics including flagyl
  6. Best solution, normalize WBC
Neutropenic colitis was found in 1.4% of children treated for a malignant condition. Although the majority of patients were profoundly neutropenic (Mean ANC = 164), 12% had a normal neutrophil count. The episode of colitis, which presents with vague signs and symptoms, is usually preceded by a precipitous drop in ANC.

Although most cases involve the cecum, the colitis may involve the ascending colon, and even the terminal ileum.

Treatment involves bowel rest, decompression, broad spectrum antibiotics (including anti-fungals), and occasionally G-CSF. Operative management is reserved for patients with bowel perforation, bleeding, or clinical deterioration.

So learned a couple of things today.

Friday, April 4, 2014

Suction device for correction of pectus excavatum

Some information to file under the "good to know" category.

The suction bell  is a device that uses negative pressure (15% below atmospheric) to pull the sternum out and into a more natural position.  The principle involves repetitive intermittent use until the deformity is corrected.

In a paper by F. Haecker, the author describes a wide range of applications times, but recommends twice daily application for 30 minutes at a minimum. After the device is positioned over the deformity, the patient uses a hand pump to apply negative pressure, which instantaneously pulls the sternum up. The duration of use is limited by pain and the development of a transient subcutaneous hematoma in most of the patients.

Long term results are not available, but over a short period of use, patients experience "dramatic" results.  In the aforementioned paper, the author reports a sternal elevation of 1.5 cm in 70% of patients within a 3 month period. Again, patient dedication and level of commitment being a major determinant of outcome.  Additionally, the author suggest that the best results tend to occur in patients with milder forms of symmetric pectus excavatum.

Needless to say, this sounds like a very promising non-operative option, though the jury is still out on what is the optimal application protocol is as well as long term results and durability of the correction




Friday, March 28, 2014

The "correction index" as a measure of severity of pectus excavatum.

Pectus excavatum is a condition where the sternum and adjacent ribs develop in an abnormal way, resulting in a depression in the middle of the chest.  The consequences of the depression are mainly esthetic, but may affect lung and cardiac function (controversial evidence)
Figure 1

The Haller index (Figure 1) has been classically used as a measure of the severity of the pectus deformity, where a HI >3.25 is considered an indication for consideration for surgical correction.

An innate fault of this measurement, as St Peter et al pointed out in their paper, is the fact that this number relies heavily on the cross sectional diameter of the chest (Figure 1; measurement a), which varies between patients.  They noted that when they measured the HI in patients with a pectus deformity, there was a 45% cross-over with normal patients. Essentially, the authors suggest that the HI is not a reliable measure of severity of a pectus deformity.
Figure 2

As an alternative, the authors recommend using a measurement they referred to as the correction index (Figure 2).  Simply put, CI is the ratio of the anticipated rise in the sternal defect after bar placement (Figure 2; measurement a-b), to the maximal anterior to posterior dimension of the inner chest, multiplied by 100.

The question then becomes, what CI should be used as an indication for surgery?  The authors suggested that a 10% or higher CI reflects a pectus deformity severe enough to warrant correction.


Friday, February 21, 2014

How do Senna laxatives work?

My frustration with my inability to find a good reference that explains how Senna based laxatives work (before I prescribed it to one of my patients with HD and encopresis) was relieved by one of our fine Pedi GI folks.  She promptly sent me this paper from the deep archives of an appropriately name journal.

Here's the answer.

Senna, an anthraquinone laxative, is a glycoside that is metabolized in the GI tract into oxy-methyl anthraquinone.  OMA's (just made that up; not the official name) soften the stool by decreasing water absorption from the colon and promote colonic contraction by stimulating the Auerbach plexus of nerves.

There you go.




Thursday, February 13, 2014

In the realm of surgical oncology, biology is King!


A gem from grand rounds today:

Law of the land in surgical oncology

Biology is King
Selection is Queen
Technical maneuvers are the Prince and Princess

Occasionally the prince and princess try to
overthrow the powerful forces of the King and
Queen, sometimes with temporary apparent
victories, but usually to no long term avail.


Blake Cady, MD