Management Of Fluid Collections Due To Acute Pancreatitis By Interventional Techniques

MANAGEMENT OF FLUID COLLECTIONS DUE TO ACUTE PANCREATITIS BY INTERVENTIONAL TECHNIQUES

Vimal Someshwar
Interventional Radiologist, Bhatia General Hospital, Mumbai.

Intra-abdominal fluid collection following pancreatitis is associated with high degree of morbidity and mortality especially when infected. Symptoms like pain, discomfort and distension of abdomen, can be quite distressing. Surgery used to be the mainstay of management of these fluid collections. Over the last 2 to 3 decades, percutaneous and endoscopy guided catheter drainage procedures, have helped improve the prognosis of this morbid condition.
Wide availability of cross sectional imaging modalities like ultrasonography and CT scanning have helped early diagnosis, as also, guided percutaneous drainage procedures. Of the two modalities, CT scan is preferred, as it thoroughly and systematically helps evaluate the entire abdominal cavity.

USG or CT guided percutaneous catheter drainage procedures are associated with a mortality rate of 6%. The normal anatomy is also less disrupted and therefore less morbidity is associated with this form of therapy.

Two types of pancreatic fluid collections which can be drained by percutaneous techniques are : (A) Pseudocysts and (B) Abscesses and necrotic collections.

(A) Pseudocysts

Cysts which are either large, causing pain, distension or are at high risk of rupture, require percutaneous drainage. Infection complicating a cyst needs early drainage.

Various procedures considered are:-

(a) Percutaneous needle aspiration
(b) Percutaneous catheter drainage
(c) Percutaneous cysto-gastrostomy
(d) Endoscopic cystogastrostomy
(e) Endosonographic cystogastrostomy

Simple needle aspiration can be performed under USG/CT guidance. 18G/16G needle is directed into the collection, as fluid is aspirated. Recurrence rate of 5% to 7% is expected following this therapy. Secondary infection and bleeding within the cyst are possible complications.

Percutaneous Catheter Drainage is the most preferred method. CT guidance is preferred. Seldingers technique is used to catheterise the fluid cavity. Cure for pseudocyst by this technique is expected to be 67-80%. Communication with the pancreatic duct determines the duration for which the catheter is to be kept in place.

Cystogastrostomy : The principle of this procedure is to allow formation of a mature tract between the cyst and the stomach and hence, facilitate drainage of the fluid through the fibrous tract. To achieve this fibrous tract, a catheter or stent is placed for at least 3 weeks. The procedure was first performed by the percutaneous technique. Endoscopy was found to be a better mordality, since there was no external tube placement.

Endoscopic Ultrasonography/Doppler further reduced the risk of injuring a blood vessel

(B) Abscesses and Necrotic Tissue

Aggressive approach is necessary as these abscesses are associated with a mortality rate of 70-80%. The present approach for the management of pancreatic abscesses, is to delay surgical explorations for 3 to 4 weeks. During this period percutaneous drainage is preferred. Multiple catheters placed simultaneously, draining all possible cavities, is mandatory.

Drainage using large bore catheters (14 Fr. - 24 Fr.) are used. Antibiotic lavage technique, wherein, antibiotic solutions are introduced from one catheter and drained after 3 hours from another catheter, have yielded better results. However, catheter drainage may be incomplete as often, necrotic tissue may occlude the catheter. Surgery should be contemplated once the sepsis is under control.

Percutaneous Interventional Technique : Salient features

i. Shortest possible route to the fluid cavity should be selected, avoiding puncturing bowel or organ.

ii. Gravity drainage should be facilitated, otherwise, suction drainage systems like Redivac, should be attached.

iii. Try to a demonstrate communication of the cavity with hollow viscera, by injecting contrast in the cavity.

iv. Catheters should be properly fixed to avoid accidental displacement. Self-retaining catheters like Pigtail, Cope-loop, Malecot’s type etc., are used. Proper skin fixation and dressing helps prevent displacement.

v. The caliber of the drainage tube should be wide with no reduction.

Percutaneous drainage procedure play an important role in the management of acute pancreatitis.

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