Toward a Unifying System for Reporting Pancreatic Fistula

Pancreatic fistula has been recently defined by the International Study Group of Pancreatic Fistula (ISGPF; Bassi et al, 2005a). This system has served as a foundation for defining and reporting pancreatic fistula among numerous studies and is an example of the efforts to unify complication reporting. The study group comprised an international panel of pancreatic surgeons working in high-volume centers, and it aimed to develop a simplified and universal definition of pancreatic fistula with a grading system based on clinical impact. Fistula was defined as “drain output of any measurable volume of fluid on or after postoperative day 3 with amylase content greater than three times that of normal serum amylase.” Three grades were applied according to clinical impact, from grade A (none) to grade C (significant; Table 25.5). As demonstrated in Table 25.6, many institutions have implemented this system for reporting the rates and outcomes of pancreatic fistula.

Independent prospective validation of the ISGPF definition and grading system has been reported. Pratt and others (2006) prospectively analyzed postoperative complications in 176 consecutive patients after pancreaticoduodenectomy. There were 53 patients with confirmed fistulae (30% incidence), categorized in the various grades: 26 patients (15%) were grade A, 21 (12%) were grade B, and 6 (3%) were grade C. No deaths were related to fistula in this study. Patients with grade A fistulas had shorter hospital stays and fewer secondary complications than patients with grade B and C fistulas, although the overall rate of secondary complications between grade B and C fistulas was not significantly different (76% vs. 100%, respectively, P = .2). Patients with grade C fistulas had a higher frequency of intensive care unit (ICU) transfer and blood transfusions and longer hospital stays compared with those who had grade B fistulas, and five of the six patients with a grade C fistula were discharged to a rehabilitation facility, significantly more than patients with grade A and B fistulae.

In an economic assessment, the authors reported a correlation between increased health care costs and increase in fistula grade. This study validated the ISGPF classification scheme by demonstrating no clinical consequence of grade A fistulas, whereas grade B and C fistulas led to more complications, longer hospital stays, and higher health care costs.

Pancreatic Leak, Fistula, and Abscess

Vin and colleagues (2008) reported a series of 908 pancreatic resections and the rate and management of pancreatic fistula, leak, and abscess. As demonstrated in Figure 25.2, a significant overlap was found among these three separately defined complications in the 158 patients in which they occurred. This further highlights the difficulty in defining discrete complications, the crossover between different definitions, and the clinical relevance of complication grading. In this study, a pancreatic fistula, defined as clinical signs or symptoms with amylase-rich drainage greater than 50 mL/day beyond postoperative day 10, was identified in 92 patients; however, in 63 of these (69%), the fluid that was drained was culture positive. These patients could therefore have been defined as having either or both a pancreatic fistula and postoperative abscess. Regardless of the definition, patients who develop a pancreatic fistula, leak, or abscess will often evidence similar findings and be treated in a similar fashion. Importantly, the type of complication (fistula, leak, or abscess) was not associated with presentation (fever, leukocytosis) or overall morbidity (duration of drainage, length of stay, ICU admission); however, these factors were similar in patients who had a similar grade of complication.

FIGURE 25.2 Categories of 158 postpancreatectomy complications following 908 pancreatic resections at Memorial Sloan-Kettering Cancer Center from 2000 to 2005.

(Modified from Vin Y, et al, 2008: Management and outcomes of postpancreatectomy fistula, leak, and abscess: results of 908 patients resected at a single institution between 2000 and 2005. J Am Coll Surg 207[4]:490-498.)

Vin and colleagues (2008) reported a 90-day mortality rate of 5% in patients who developed fistula, leak, or abscess. These complications were more common in men and in patients undergoing treatment for bile duct, ampullary, and duodenal tumors (63 [31%] of 206) compared with pancreatic tumors (95 [14%] of 702; P < .001). Type of resection (PD vs. distal pancreatectomy), tumor histopathologic subtype, and PBD were not associated with occurrence of fistula, leak, or abscess. Surgical drains were placed in 88 patients with these complications. The surgical drain alone, without additional interventional radiologic management, was successful for treatment in 16 (18%) of 88 patients, and 133 patients were managed with percutaneous drainage alone.

Duration of drainage was defined as the time from initial drain placement when performed percutaneously, the date of operation for drains placed intraoperatively, or the date of reoperation for collections requiring operative drainage to the time of drain removal. Mean duration of drainage was 38 days (range, 3 to 228 days). Factors associated with drainage for more than 30 days on multivariate analysis included distal pancreatectomy (odds ratio [OR], 4.3; P = .01) and drain output greater than 200 mL during the first 48 hours (OR, 2.9; P = .02). In this study, PD patients more often had initial fever, culture-positive collections, and drainage more than 30 days compared with distal pancreatectomy patients. Those in the latter group, by contrast, were more often readmitted, had initial drainage on readmission, and were more likely to have prolonged drainage.

Delayed Gastric Emptying

Delayed gastric emptying (DGE) after PD is common (see Table 25.2) and is typically reported in 9% to 16% of patients. A review of randomized controlled trials for treatment of DGE has been recently published (Traverso & Hashimoro, 2008), examining the literature for level I evidence, and four trials were identified that focused on the prevention of DGE. The largest study from Yeo and others (1993) randomized patients to erythromycin or control and found no reduction in the incidence of DGE. In a separate study, erythromycin did significantly reduce postoperative DGE, but the study was very small, and DGE occurred in 57% of patients in the control arm (Ohwada et al, 2001). Tani and colleagues (2006) randomized patients to retrocolic or antecolic gastrojejunostomy and found a significantly lower rate of DGE with the antecolic approach.

Although DGE and pylorus preservation have been a concern, to date no study has found a difference in the incidence of DGE following conventional compared with pylorus-preserving procedures (Diener et al, 2007). As discussed earlier in this chapter, and as highlighted in Table 25.7, the reported incidence of DGE was lower in two studies analyzing anastomotic technique. Bassi and colleagues (2005b) found a statistically significant reduction in DGE in patients who had PG compared to PJ. In the study by Yeo and others (2002), comparing radical with standard PD, an increase in DGE was seen in the radical group. It is important to note, however, that neither study had DGE as the primary end point.

Among these studies, significant variability was observed in the range of reported incidence of DGE. As with pancreatic fistula, part of the variability in incidence across studies was from the variation in definition. The ISGPF recently devised a formal grading system for DGE based on duration of nasogastric tube placement and the timing of patients’ tolerance of solid food (Wente et al, 2007).

The authors’ current management strategy for patients with significant DGE—that is, the inability to tolerate solid food or prolonged nasogastric tube requirement—is to perform cross-sectional imaging to exclude secondary causes, such as fistula, leak, or abscess. As initial treatment, intravenous metoclopramide is given with or without the addition of oral erythromycin. The possibility of an underlying structural abnormality should be investigated with upper gastrointestinal (GI) series or esophagojejunoscopy, which has the potential to evaluate and treat an anastomotic abnormality. In the setting of prolonged DGE, endoscopic placement of a feeding jejunostomy may be required, but reoperation is reserved for patients who fail to progress after prolonged parenteral nutrition and medical therapy.

Hemorrhage

Postoperative hemorrhage is a potentially lethal complication after pancreatectomy, and it can occur in the immediate postoperative period (<7 days) or in a delayed fashion (>14 days). Management is often guided first by the patient’s hemodynamic stability. Any unstable patient should be transfused and taken for reexploration. Patients who can be easily stabilized may be candidates for endoscopic or interventional radiologic management. Intraluminal bleeding is most commonly from the gastrojejunal anastomosis and can often be managed with endoscopic therapy. Extraluminal bleeding from arterial pseudoaneurysm (Fig. 25.3) or vascular erosion from a pancreatic fistula typically occur later, following operation, and these can be approached via angiographic embolization in stable patients. A high index of suspicion is critical, as mortality from late postoperative hemorrhage is significant (Brodsky & Turnbull, 1991).

FIGURE 25.3 After Whipple procedure for pancreatic adenocarcinoma, a 63-year-old female patient had clinical evidence of bleeding 3 weeks after surgery. A, Abdominal computed tomography during the arterial phase revealed a large hematoma (arrowheads) centered in the subhepatic space with central highly enhancing components within this hematoma consistent with the lumen of a pseudoaneurysm at the origin of the gastroduodenal artery (arrows). B, Conventional angiography confirmed a pseudoaneurysm of the gastroduodenal artery (arrow), which was isolated by occluding the proper hepatic (outflow) and common hepatic artery (inflow) with multiple stainless steel coils. C, The angiogram after occlusion showed coils in the hepatic arteries (arrows) with lack of enhancement of the hepatic arteries and the pseudoaneurysm of the gastroduodenal artery. D, After placement of a covered stent (between arrows) into the hepatic artery in a 46-year-old male who had gastroduodenal artery stump bleeding after Whipple procedure. Covered stent placement is an alternate treatment to coils that allows preservation of hepatic artery flow.

Yekebas and others (2007) analyzed the treatment and outcome of 87 patients who had postoperative hemorrhage in a series of 1669 pancreatic resections in 1524 patients (overall hemorrhage rate, 6%). Hemorrhage was classified as mild in 36 patients (41%) and severe in 51 patients (59%); 29 patients (33%) had a sentinel bleed. The bleeding site was extraluminal in 51 (59%) and intraluminal in 36 (41%); 17 patients had what appeared to be extraluminal hemorrhage, but further evaluation confirmed bleeding from the transected pancreas or resection cavity; and 34 patients (39%) had pancreatic fistula that preceded hemorrhage.

Treatment included endoscopy, angiography with coil embolization, and reoperation. Endoscopic treatment was successful in three (20%) of 15 patients with intraluminal hemorrhage. Any patient with true extraluminal hemorrhage required reoperation, and 17 patients had bleeding from the pancreatic anastomosis and had a secondary anastomotic leak. Among 25 patients treated with coil embolization by angiography, coiling was successful in 20 (80%). Reoperation was performed in 60 patients; in 33, surgery was the first-line treatment of hemorrhage, and the remaining 27 were for failure of nonoperative measures. This included patients with pancreatic fistula (13 patients) and/or vascular abnormalities such as pseudoaneurysm and erosions (12 patients). Fourteen patients died from hemorrhage, for a mortality rate of 16%. All of the mortalities were in the group with delayed hemorrhage, which occurred after postoperative day 5.

This and other studies have demonstrated that significant morbidity and mortality are associated with postoperative hemorrhage, especially when delayed beyond postoperative day 5 (Choi et al, 2004). These patients often require reoperation or interventional radiology procedures to halt life-threatening hemorrhage. Furthermore, patients who experience a postoperative hemorrhage often have underlying complications that require treatment, such as pancreatic fistula. If angiographic embolization successfully treats hemorrhage, cross-sectional imaging should be performed to assess for the presence of leak, fistula, or abscess that would require drainage.

Image-Guided Abdominal Drainage

One of the major advances in the management of postoperative fluid collections and abscesses over the past 2 decades has been the introduction of image-guided percutaneous drainage procedures, which have changed the management of patients previously requiring an urgent reexploration. Small fluid collections at the resection site are common in the immediate postprocedural period and usually resolve spontaneously. These collections generally do not require an interventional procedure, but they can be aspirated with a needle if there is clinical suspicion for infection (Gervais et al, 2001). Abscess drainage can be performed with US but is done more often with CT guidance (see Fig. 25.4). The technical success rate has been reported to be 96% to 100% (Betsch et al, 2002; Lagan et al, 2008; Zink et al, 2009). The complication rate of interventional drainage of fluid collections is low, however, bleeding and bowel perforation have been reported (Lambiase et al, 1992; Betsch et al, 2002; Lagan et al, 2008; Zink et al, 2009).

There are two widely used techniques of imaging-guided abscess drainage: the trocar technique and the Seldinger technique. The trocar technique is performed by direct puncture of the abscess using a trocar needle, which is covered by the catheter, and by removal of the trocar needle after the catheter is in position. The Seldinger technique is performed by puncture of the abscess using a coaxial needle, through which a guidewire is inserted into the fluid collection. The needle is then removed, leaving the guidewire in situ. The needle tract is serially dilated by exchange of dilators and guidewires. Finally, a drainage catheter is inserted into the abscess over the guidewire. The advantage of the Seldinger technique is that it is less traumatic to the surrounding tissue because of the initial use of small needles and the subsequent dilation with dilators, until the size of the catheter is reached. The advantage of the trocar technique is that this procedure is easier and faster to perform. Independent of the technique, a wide range of drainage catheters is available, ranging from 6 to 14 Fr in diameter (Gerzof et al, 1978; Goletti et al, 1993; vanSonnenberg et al, 1984). Although no difference has been seen comparing 7 and 14 Fr drainage (Roethlin et al, 1998), the diameter of the catheter may be chosen on the basis of viscosity of the content.

After catheter placement, the abscess is emptied, and specimens are sent for bacteriologic examination and culture and for evaluation of amylase levels. Postprocedural drain care includes local protection of the skin incision and flushing of the drain with gentle saline solution two to three times a day to prevent drain clogging. Documentation of the daily output volume is mandatory to evaluate drain function.

Percutaneous drainage of abdominal fluid collections has been reported to be as effective as operative drainage. No significant differences have been reported in mortality or morbidity, and the duration of hospital stay has been similar when patients were matched for age, sex, diagnosis, and abscess etiology and location (Hemming et al, 1991; Olak et al, 1986).

The earliest experiences with CT-guided percutaneous drainage of abdominal abscesses were reported in the late 1970s (Gerzof et al, 1978). Since then, the efficacy of the procedure has been confirmed in several studies, in which success rates of drainage of abdominal fluid collection or abscesses were 62% to 96% (Zink et al, 2009; Betsch et al, 2002; Lagan et al, 2008; Lambiase et al, 1992; Gerzof et al, 1978; vanSonnenberg et al, 1984; Cantasdemir et al, 2003; Cinat et al, 2002; Freeny et al, 1988). Multiple drainage procedures may be necessary in the same patient to achieve clinical success (Zink et al, 2009; Cinat et al, 2002).

A similar high rate of successful imaging-guided drainage can be achieved in patients with accompanying pancreatic fistula. The reported success rates in patients with accompanying fistulas have been 67% to 89% (Zink et al, 2009; Aassar et al, 1999; Kerlan et al, 1985; Singh et al, 2006). One important prognostic factor associated with decreased success of percutaneous drainage is the presence of yeast in the abscess fluid (Cinat et al, 2002).

Although studies have shown that fluid collections with pancreatic fistulae have similar drainage success compared with fluid collections without an active pancreatic leak, fluid collections with pancreatic fistulae require longer drainage. Zink and others (2009) reported the median duration of drainage in patients with abscess was 29 days compared with 11 days in patients with a sterile fluid collection. Patients with a pancreatic leak had median drain duration of 30 days (Zink et al, 2009).

Percutaneous Biliary Drainage

Biliary obstruction or leak is another example of a complication that can occur after pancreatic surgery that can be managed using nonoperative techniques. Endoscopic management is possible but frequently difficult because of the alteration in the anatomy as a result of surgery. Malignant strictures can be palliated with a biliary drainage catheter, and metallic stents may be useful, but they frequently occlude in less than a year (Dahlstrand et al, 2009). Therefore, the decision to pursue metallic stenting often hinges upon a patient’s life expectancy. Benign strictures can be relieved with balloon dilation but may also recur and require repeated dilations (Kocher et al, 2007). Bile leaks at the hepaticojejunostomy usually require both drainage of the bile fluid collection and PBD to divert bile and allow for the leak to heal (Gervais et al, 2001; Dorico et al, 2008).

Angiography and Embolization (See Chapter 19)

Postoperative bleeding pseudoaneurysms usually occur relatively late after surgery and are associated with a high mortality rate (Rumstadt et al, 1998). In a report by Otah and colleagues (2002), the average presentation was 19 days after surgery, and the majority of patients were already discharged home. All patients in this report first had a sentinel bleed with minimal blood seen in drains or in the GI tract. Sentinel bleeds were defined as the appearance or paradoxical increase in the amount of blood from the abdominal drains or GI tract combined with a decrease in hemoglobin of 2 g/dL at least 3 days after surgery (Tien et al, 2008). This has led some to take a very aggressive approach to the presence of even minimal bleeding beyond 3 days after resection. CT angiography can sometimes identify the vessel of interest, however, this potential benefit must be weighed with the additional contrast dose needed to perform CT. Given that the likely bleeding source will be identified on angiography, the CT may not be beneficial, especially in patients with borderline renal function. Many believe angiography with possible embolization should be pursued in the presence of a sentinel bleed, with reoperation reserved only for the presence of active, massive bleeding or failed embolization (Otah et al, 2002; Blanc et al, 2007). The success rate is approximately 85% (Tsai et al, 2007).

Pseudoaneurysms after pancreatic surgery occur in the gastroduodenal artery most commonly, followed by the hepatic artery, superior mesenteric artery, and splenic artery (Tien et al, 2008). Selective coil embolization across the pseudoaneurysm is successful in approximately 85% of patients (Tsai et al, 2007). More recently, however, some have reported the use of covered stents, instead of coils, to exclude the pseudoaneurysm while preserving flow to distal structures supplied by the injured vessel (Narumi et al, 2007; Suzuki et al, 2009; Wallace et al, 2007). A demonstration of these images and techniques is shown in Figure 25.3.

Drain Management

After catheterization of the abscess, a specimen is obtained for microbiology and chemistry studies (amylase, bilirubin). The collection is drained before gentle contrast injection to limit possible bacteremia that might occur in a distended collection during injection. Contrast injection can identify fistulae and may show additional pockets of drainable fluid. Once drainage is complete, imaging should be obtained to document a collapsed cavity. The catheter should be marked at the skin site as an indicator of possible migration during the patient’s follow-up management. Saline flushes should be used two to three times daily to maintain a patent tube.

After patients have defervesced and otherwise improved clinically, they may be eligible for discharge with their catheters for home management. Whether the patient is in the hospital or at home, the catheter output should be carefully monitored. If the daily net output remains high (>50 mL) for several days, an ongoing fistula or leak may be present. If the daily net output diminishes to fewer than 10 mL, consideration should be given for a tube study to evaluate for a functional tube, particularly if any systemic signs of recurrent infection are evident. A saline flush should be easily injected into the tube with the complete volume returned upon aspiration. If the tube is functional and has not been dislodged, and the patient is not having pain or fever, then it may be removed. On the other hand, if the saline flush cannot be completely aspirated, the tube has been moved from its skin marking, or the patient’s clinical condition has changed, then the tube should be imaged.

Imaging method depends on physician preference: some prefer a fluoroscopic tube injection; others prefer a CT scan, and others still prefer both studies. The fluoroscopic contrast injection will show the remaining cavity size and the presence of fistula. The CT can also show the cavity size but not necessarily a fistula. If the CT shows a collection remaining around the catheter, a malfunctioning tube must be suspected, as functional tubes should have no collection around the tube. If imaging demonstrates nondraining locules, some prefer to try an intracavitary tissue-type plasminogen activator (TPA). One report showed an 89% success rate using TPA to drain abscess refractory to simple catheter drainage (Beland et al, 2008). The risk of bleeding should be carefully considered prior to the use of TPA in a postpancreatectomy patient, and this should be utilized only in carefully selected patients.

Postpancreatic drains may be present for several weeks. The study by Vin and colleagues (2008) demonstrated a mean duration of 38 days (range, 3 to 228 days). Pancreatic drains ideally require an active participation by the patient or patient’s caregivers.

Supportive Management of Pancreatic Fistula

Patients with infected fluid collections are typically treated with broad-spectrum antibiotic therapy until clinical signs and symptoms of infection resolve. To date, no strong clinical evidence is available to show that somatostatin analogs enhance fistula closure (Stojadinovic et al, 2003). A recent prospective trial randomized patients with pancreatic or enterocutaneous fistulae to intramuscular injection of 30 mg of a sustained-release somatostatin analog, lanreotide, or placebo (Gayral et al, 2009). The investigators found a significant reduction in fistula output within 72 hours of injection (primary end point), however, no difference was found in fistula closure rates (secondary end point).

To date, no evidence of any benefit has been shown for supplemental parenteral or enteral nutrition in patients with pancreatic leak who can tolerate oral intake. It is our general practice to allow patients ad libitum feeding as tolerated. More aggressive supportive care, such as total parenteral nutrition, is reserved for patients with secondary complications precluding oral intake or extremely high output that is responsive to initial bowel rest. Patients are managed in the hospital until they have return of oral intake and bowel function and can reliably manage their drain with or without nursing assistance.

Reoperation

Improvements in interventional and endoscopic techniques have reduced the need for reoperation in many patients after pancreatic resection. Reoperation is still necessary, however, in 3% to 5% of patients following pancreatic or liver resection, and it should be considered in patients with clinical deterioration from hemorrhage, abscess, leak/fistula, or intestinal ischemia. Reoperation rates, as seen in Table 25.2, range from 4% to 15% and vary according to type of pancreatic resection. Standop and others (2009) reported their series of 31 patients (11% of 285 consecutive PDs) who required reoperation. The most common indications for reoperation were hemorrhage (29%) and intraabdominal abscess (23%). Among patients who required reoperation, 45% required a second operative procedure. The mortality rate among patients requiring reoperation was 13% compared with 2% for the cohort of patients that did not require reoperation. Significant mortality in patients requiring reoperation is as high as 60% in some series, indicating the critically ill nature of these patients (Hoshal et al, 2004).

Imaging

US, helical CT, and MRI/MRCP are the noninvasive diagnostic procedures widely applied to the liver and biliary system. Ordinary postoperative fluid collections, bilomas, hematomas, and abscesses can be detected with these modalities. Acute and subacute hemorrhage usually shows a typical high density in CT and can therefore be reliably diagnosed with this modality. In addition, active bleeding can be demonstrated by contrast media extravasation on contrast-enhanced CT. In particular, the typical appearance of biloma on imaging is that of an encapsulated mass with space-occupying and space-conforming characteristics contiguous with the liver resection plane or biliary structure (Vujic & Brock, 1982). Repeated imaging may be necessary to clearly differentiate between uninfected postoperative fluid collections and abscesses because of overlapping. In addition, an ordinary postoperative fluid collection may progress to become an abscess. FNA may be necessary to rule out infection when a patient’s condition is suspicious for infection and imaging shows an equivocal fluid collection.

Hepatic Abscess Drainage

Percutaneous drainage of a hepatic abscess is a minimally invasive, image-guided procedure that carries lower morbidity and is less expensive compared with surgical treatment (Ferraioli et al, 2008). Preparation for the procedure includes evaluation for coagulopathy, choosing the imaging modality for guidance during the procedure (US or CT), and choosing the appropriate route of access. Single abscesses may be drained with US guidance, whereas multiple abscesses may require CT guidance and placement of multiple catheters (vanSonnenberg et al, 2001).

The technical success rate of US- and CT-guided hepatic catheter drainage has been reported to be 94% to 96% (Liu et al, 2009). Abscesses located near the dome of the diaphragm may be technically more difficult to drain without transgressing the pleura, but clinical success rates for percutaneous drainage of intrahepatic abscesses of 70% to 100% have been reported (Akinci et al, 2005; Attar et al, 1986; Dondelinger et al, 1990; Gerzof et al, 1985; Giorgio et al, 2006; Rajak et al, 1998; Mezhir et al, 2010). We reported that yeast in culture and the presence of an obstructed biliary tree were independent predictors of failure of percutaneous drainage of pyogenic hepatic abscess (Mezhir et al, 2010). When biliary obstruction is present, relief of the obstructed biliary tree is mandatory for successful abscess treatment (Fig. 25.6). Size and the presence of loculations did not preclude successful percutaneous drainage in this study.

FIGURE 25.6 A 46-year-old male patient with HIV and hepatitis B infection after partial left hepatectomy as a result of hepatocellular carcinoma. A, Postoperative follow-up computed tomography revealed a fluid collection at the liver resection site (asterisk); it was treated with percutaneous catheter placement. B, Contrast injection into the cavity under fluoroscopy revealed the small cavity (asterisk) communicating with the common hepatic bile duct (arrow). Contrast media is noted in the duodenum (arrowhead). Endoscopic retrograde cholangiopancreatography was performed, and a plastic stent was placed into the common bile duct to decrease the output of the fistula.

Although single, small abscesses are generally adequately treated by percutaneous drainage, debate continues on the optimal treatment of large, multiloculated abscesses. Nonetheless, similar clinical success rates of 82% to 92% have been reported for single and multiple abscesses and for single multiloculated and multiple multiloculated abscesses (Liu et al, 2009; Ogawa et al, 1999). Other authors have reported higher success rates for unilocular abscesses and have proposed a treatment algorithm, with small abscesses being treated with antibiotics alone; large, unilocular abscess with percutaneous drainage plus antibiotics; and large, multiloculated abscessed treated with surgical therapy (Hope et al, 2008). It has been reported that repeated catheter drainage improves the success rate (Hope et al, 2008). The clinical success rate for treatment of unilocular abscesses was 83% if a single drainage was performed and 100% if repeated drainages were performed. The success rate for treatment of multilocular abscesses was 33% for single drainage and 50% if repeated drainages were performed (Hope et al, 2008). Some suggest use of intracavitary TPA to aid with multiloculated collections refractory to simple percutaneous drainage (Beland et al, 2008).

Several studies have shown the superiority of percutaneous catheter drainage over needle aspiration. For abscesses, needle aspiration was successful in 60% to 92% of patients, whereas percutaneous catheter drainage was successful in 97% to 100% of patients (Giorgio et al, 2006; Rajak et al, 1998; Singh et al, 2009; Zerem & Hadzic, 2007). Among the successfully treated patients, the average times for clinical improvement, hospital stay, and total resolution of the abscess were similar in the two treatment groups (Giorgio et al, 2006; Rajak et al, 1998; Singh et al, 2009; Zerem & Hadzic, 2007). In one study no significant difference in the success rate between aspiration and drainage was reported, but multiple aspirations were required in the aspiration group to achieve success (Yu et al, 2004).