Wednesday, May 13, 2015

Do we really need screening UGI's before G tube placement?

The logic behind performing screening UGI studies before g tube placement has always escaped me.  I understand the rationale behind screening for malro before a Nissen +/- g tube, since reflux could be due to some level of partial obstruction from malro; but why UGI's for g tubes without reflux?  It certainly is not a useful test to screen for reflux.  We definitely do not need to know where the stomach is before place a g tube, so why the radiation exposure?

A study by Abbas et al noted that the incidence of unexpected malro identified by screening UGI's performed for patients undergoing a routine gastrostomy tube placement is 1.7% (5/229).

Even if one accepts that avoiding a potential catastrophic event in 2 patients is worth the risk of radiation (300 cGy/UGI study) to the other 98, this logic should be applicable to all preop patients (since the need for a g tube does not necessarily select out a population at higher risk of malrotation).
So why do we not screen all preop patients with UGI's?(not suggesting that we should, for the trolls out there!).

Some more data to help support what we do (or don't do). 

Thursday, October 30, 2014

Hepatico-Jejunostomy or Hepatico-duodenostomy after resection of a choledochal cyst?

Cholangitis!!!... is that not the main concern when food is passing right next to the hepatic ducts after a hepatico-duodenostomy (HD), with no interposed common bile  duct or sphincter of Oddi?  That was what I thought until I was told otherwise, and confirmed with the limited available evidence.

When a Kocherized (salute to the verb-nouns) duodenum can reach the hepatic ducts for reestablishing continuity after choledochal cyst resection, the laparoscopic operation becomes simpler, more physiologic, and avoids potential complications related to the roux-en-y reconstructions.  Additionally, it allows for future endoscopic access to the anastomosis in case an anastomotic stricture or intrahepatic stones develop. No much controversy there.

But what about cholangitis, how can it be OK for food to pass right by the hepatic ducts and not cause an infection.

In a paper by Santore et al out of CHOP, the authors retrospectively reviewed charts of 59 patients who underwent open resection by the same surgeon with reconstruction using either HD (66%) or HJ (34%). After a mean of 2.3 years follow up for HD and 3.5 years follow up for HJ, only one patient in the HJ developed cholangitis.  Additionally, there was no significant difference in the rate of postoperative leaks or strictures.

Another argument against reconstruction with a HD relates to the risk of bile gastritis.  A meta-analysis of several papers with a total of 679 patients (60% of whom underwent reconstruction with a HD) suggested that patients who are reconstructed using a HD are at increased risk of bile gastritis (5.9% for HD vs. 0% for HJ).  It is clear how reconstruction with a HJ completely diverts bile away from the stomach and thus prevents any bile gastritis.  It is unclear to me, however, how placing the anastomosis in the duodenum, and downstream of a perfectly healthy pylorus, is any different from the normal physiologic drainage of bile, and why that would cause gastritis.

I'm on team HD.

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.