Wednesday, July 27, 2011

How often are common bile duct stones found in children suspected of having them?

This read stemmed from a literature search looking for articles addressing missed CBD stones in children not suspected of having them (no hx of jaundice, pancreatitis, normal CBD on U/S etc..). Instead I ran into this interesting article, out of Sick Kids in Toronto, looking at kids with findings consistent with CBD stones who were either managed by pre-operative ERCP, or had undergone an intra-operative cholangiogram, followed by ERCP when the IOC was positive.

202 patients with gallbladder stones, 48 of whom (23.7%) had suspected CBD stones. Preoperative ERCP, which was performed on a third of patients with suspected CBD stones, was positive in 21.4% of cases. Most of the rest of patients with suspected CBD stones underwent an IOC, which was positive in 6.5% of cases. Based on their results, the authors recommended an IOC as the initial investigative study since it involves less risk to the patient than does an ERCP, which was negative in around 80% of cases.

An IOC seems to be an excellent way to avoid unnecessary ERCP's, as long as a skilled gastroenterologist with a high ERCP success rate is available (to avoid a situation where a CBD stones are identified intraop, and an attempt at ERCP fails post op!). What is interesting about this study is the discrepancy between the finding of stones in the preoperative ERCP group and the IOC group. This could be because the ERCP may be more sensitive than the IOC, but potentially there might have been a selection bias, where patients who were more likely to have CBD stones (elevated bilirubin (8 vs 2), markedly dilated CBD (14 vs. 7) etc...) might have been selected to undergo and ERCP vs IOC.

Reference
Mah et al. Management of suspected CBD stones in children: role of selective IOC and ERCP. Journal of pediatric surgery (2004)39 :808-812

Thursday, July 21, 2011

How can laparoscopy help evaluate patients with suspected rotational anomalies?

Again, the subject of rotational anomalies and equivocal UGI findings came up. The next day, this paper by Hsiao et al out of Sick Kids in Tornoto was in JPS. Here the authors discuss the utility of diagnostic laparoscopy as a tool to help corroborate UGI findings, or as a tie breaker for equivocal UGI studies.

The article was based on two premises. The first is what defines malrotation vs. non-rotation. Malrotation, here, was defines as the DJJ and the cecum near the midline, and the base of the mesentery less than 50% of the diameter of the abdomen. Non-rotation was defined as DJJ to the right of midline, ceceum in the lower left or central abdomen, small bowel on the left side, colon on the right, and base of mesentery is longer than 50% of the diameter of the abdomen. The other premise is that the small bowel is not at risk of midgut volvulus when the base of the mesentery is longer than 50% of the diameter of the abdomen (as in normal and non-rotation), and a Ladd's procedure is not necessary.

Very few people would argue that an infant with bilious emesis who is found to have an abnormal UGI needs exploration. The issue becomes more controversial when abnormal UGI studies are found in children with no symptoms or chronic and/or non-specific symptoms. This is the group of patients this paper addressed.

The UGI results studies included findings consistent with malrotation, malrotation with volvulus, non-rotation, or equivocal findings. Of the patients with UGI findings consistent with malrotation, ~60% had malrotation confirmed by laparoscopy (with or without volvulus), and the rest had either non-rotation (30%) or were normal (10%) (both conditions the authors believe do not need surgical correction). When UGI's showed non-rotation, laparoscopic evaluation was consistent with the diagnosis in all patients. Finally, of the patients with an equivocal UGI, a third had malrotation with/without volvulus, and the rest were found to be either non-rotated (48%) or normal (21%) on laparoscopic evaluation.

So if we accept that a mesenteric base longer than 50% of the diameter of the abdomen constitutes a stable mesenteric base not prone to volvulus (a finding confirmed by laparoscopy), laparoscopy can be an important tool that can help us manage this perplexing population of patients with no/vague symptoms and inconclusive UGI studies.


Reference:
Hsiaoo M, Langer JC. Value of laparoscopy in children with a suspected rotation abnormality on imaging. Journal of Pediatric Surgery (2011) 46, 1347-1352

Tuesday, July 5, 2011

Tumor spillage and Wilm's tumor: types and implications

Tumor spillage during resection of a Wilm's tumor has substantial implications on prognosis and therapy. Spillage immediately upstages a patient to Stage III, and depending on the type of spillage, commits the patient to either flank (local spillage) or total abdominal radiation (diffuse spillage).

Intraoperative recognition and documentation of spillage, whether pre-exiting or secondary to manipulation, thus has substantial implications on adjuvant therapy. With that in mind, it is important understand the different types of spillage or peritoneal soilage by tumor.

Based on the COG's AREN03B2 Renal Biology Protocol handbook (2010), the peritoneum is concidered soiled (tumor spill) when:

1. There is intraoperative tumor spillage
2. The tumor is biopsied
3. The tumor has ruptured

Spillage occurs whenever the tumor capsule is violated. If adherent organs (eg. diaphragm) are resected without violation of the capsule, this is not considered spillage. Whenever one cuts across tumor, including tumor present within vessels, or the tumor is removed in more than one piece, spillage is assumed to have occurred.

Tumor biopsy, whether done through a percutaneous anterior or retroperitoneal approach, or using an open approach, is considered local spillage unless indicated otherwise by the surgeon.

Tumor rupture can be spontaneous or post-traumatic with subsequent tumor cell dissemination in the peritoneal cavity. Tumor rupture is usually considered diffuse soilage, though in some cases it may be clearly isolated to the retroperitoneal space and considered local spillage. The presence of a hematoma implies tumor cell spread and diffuse soilage.

Because of the various types of soilage, and their different implications (either flank or total abdominal radiation), the surgeon should completely and clearly document how the soilage occurred and whether it was thought to be diffuse or local. If tumor thrombus is encountered, the surgeon must clearly describe whether it was removed en bloc, in more than one piece, and if residual thrombus was thought to be left behind.