notes by dr. Claudio Italiano
It is a sophisticated and expensive technique, especially in recent helical and
multilayer versions with contrastographic study in the arterial and venous phase,
and has a high sensitivity and specificity in the diagnosis of neoplastic
obstructive jaundice. In addition to determining the nature and location of the
obstruction, the CT allows to express a judgment of resectability of the
neoplasia; in fact, it provides precise information on the size of the tumor
mass, on the invasion of the vascular structures and on the presence or absence
of hepatic and lymph node metastases.
The disadvantages of the method are mainly represented by the high costs of the
equipment and the need to acquire the continuous evolution of the
instrumentation.
It is a very fine and precise technique that has supplanted the invasiveness of
the CPRE; in particular the cholangioranceanza-magnetic allows to evaluate
pathologies in the biliary and pancreatic way with a good sensitivity and
specificity. With MRI, in addition to the lesion, it is possible to demonstrate
the involvement of peripancreatic and perihilic vessels and visualize the bile
and pancreatic ducts. The method requires long execution times compared to those
of CT, is burdened by high costs to acquire the instrumentation and has very
specific contraindications.
CPRE and, to a much lesser degree, trans-hepatic percutaneous cholangiography (PTC),
found wide indications in the diagnosis of biliary strictures until the end of
the last century. The CPRE used only for diagnostic purposes has been almost
completely abandoned because in 3-7% of cases it can be responsible for
complications: pancreatitis, hemorrhage, perforations and cholangitis. The
evolution and diffusion of diagnostic methods by image have considerably reduced
the use of both CPRE and PTC.
Ecoendoscopy (EUS). Minimally invasive compared to the previous methods, the EUS
has taken a leading role in the diagnosis of obstructive jaundice, as it has
proved to be a valid means to recognize the neoplasms, even small (<2 cm), to
determine the vascular and parietal invasion, to establish the involvement of
the perivisceral lymph nodes and those of the celiac tripod The effectiveness of
the EUS has been implemented by the possibility to realize, with sectorial
devices, needle-aspirated under echoendoscopic guidance (EUS-FNA).
• is invasive compared to other usable ones; in some patients deep sedation is
required if the investigation time is prolonged;
• tends to overpower the lesions;
• its implementation is limited by the presence of duodenal stenosis;
• it is an operator-employee survey; it requires a remarkable experience for the
complex interpretation of the bilio-pancreatic ecoenoscopic anatomy;
• does not recognize hepatic and peritoneal micrometastases;
• the instrumentation has high costs.
Endoscopic palliation of neoplastic jaundice is a therapeutic treatment that
does not influence the survival of patients, but has the sole purpose of
attenuating symptoms and improving the quality of life remaining. The
implementation of palliative endoscopic therapy, precluding any possible
implementation of a treatment with intent of radical cancer, can not disregard
the knowledge of the site of the obstruction of the VBP. The strictures of the
biliary tract are distinguished, from the topographic point of view, in:
1. stenosis of the upper third (or hilar) which may involve the right and left
hepatic ducts or the common hepatic up to 2 cm from the confluence.
2. Stenosis of the middle tract located 2 cm below the confluence of the hepatic
to the upper edge of the first portion of the duodenum.
3. Stenosis of the lower tract involving VBP in the tractodododenal and
intrapancreatic choledochus tract.
Bile drainage is ensured by the perendoscopic placement of plastic (polyethylene, polyurethane or teflon) or metal prostheses. The most widely used plastic prostheses have a caliber of 10 Fr., are positioned under fluoroscopic guidance after a minimum sphincteromy and a release system that facilitates their insertion. The technique, simple and effective in expert hands, can be done in a day-hospital or at most with a shelter of 24-48 hours. The metal prostheses, available of various types, have a caliber that can reach 30 Fr., are positioned with the same technique used for plastic prostheses but with different delivery systems. Both plastic or metal implants are successfully inserted in 90% of patients; the failure is linked to the presence of a duodenal stenosis, which does not allow the vaterian area to be reached with the endoscope, or a tight stenosis of the VBP, which does not allow the stenosis to be overcome with the guide wire. Although endoscopic palliation of neoplastic itteri can be considered a safe and effective method, it is burdened by early and late complications. The early complications, which occur from 3 to 10% of cases, are related to the sphincterotomy or the same positioning of the prosthesis and are represented by: pancreatitis, cholangitis, perforations and hemorrhages. The most frequent complication is the cholangitis that depends both on the bacterial contamination of the VBP during endoscopic maneuvers, and on an inadequate post-procedure biliary drainage. To avoid the occurrence of such a serious complication, antibiotic prophylaxis is always performed or, in the case of persistence of the contrast agent in VBP, percutaneous drainage by PTC. Performing the sphincterotomy, prior to placement of the prosthesis, may result in perforations or bleeding that only rarely require surgical therapy. The perforations are treated with conservative therapy and monitored to highlight the possible formation of a retroperitoneal abscess or an aggravation of the patient's clinical condition that may indicate an operation. The occurrence of a hemorrhage, in the course and after endoscopic treatment, usually resolves spontaneously or with an endoscopic haemostasis (injection with 1/10 adrenaline sclerosis needle or electrocoagulation), only rarely should surgery be used. Late complications, represented by occlusion, migration, and almost exceptionally by the breakage of the prosthesis occur from the eighth day of endoprosthesis positioning.
The occlusion of the prosthesis is determined by the deposition of a
bacterial biofilm that facilitates the deposition of biliary sludge. Various
studies have been carried out to prevent the obstruction of the prostheses,
using antibiotics or choleretic, but the results have been conflicting and it
has not been shown that these treatments prolong the patency. Patients who
undergo this complication have the reappearance of symptoms from obstructive
jaundice or more frequently from suppurative cholangitis which are resolved by
endoscopic replacement of the occluded prosthesis. Frequent replacements require
as many re-deployments with an increase in costs. For this reason, in patients
whose life expectancy is predictably longer than four months, it is recommended
to use metal implants that, although more expensive than plastic ones, become
more difficult to obstruct. If the prosthesis is positioned correctly, it is
unlikely to migrate, either within the biliary tract or towards the duodenum.
Both events are resolved endoscopically with the removal of the dislocated
prosthesis and its replacement. Particular attention should be paid to distal
migrations which, if recognized late, may be responsible for duodenal
perforations.
gastroenterology