Computed tomographic guidance of percutaneous needle aspiration and drainage of abdominal abscess

Journal of Computed Tomography 6:127-133, 1982

COMPUTED TOMOGRAPHIC GUIDANCE OF PERCUTANEOUS NEEDLE ASPIRATION AND DRAINAGE OF ABDOMINAL ABSCESS ROLF P. GOBIEN, JEREMY W. BARBARA S. GOBIEN, JOSEPH

R. YOUNG, NANCY S. CURRY, F. VALICENTI, AND H. DAVID

Percutaneous thin needle aspiration biopsy [TNAB) of solid abdominal masses is an established technique. Combining the techniques of TNAB with those of percutaneous biliary and renal drainage can result in successful nonoperative management of abdominal abscesses. Twenty consecutive patients were referred for this procedure. TNAB alone was performed in 4 patients. TNAB followed by percutaneous drainage was accomplished in 16 patients. Of the 4 patients who had TNAB alone, it was curative in 2, and 2 were elected to have surgical drainage. Of the 16 patients who underwent percutaneous drainage, it was curative in 14. One patient was discovered at surgery to have a necrotic malignant tumor. A second patient required surgery. KEY WORDS: Abscess-abdominal, Abscess Drainage, Abdomen, Abscess, Biopsy Guidance

INTRODUCTION Abdominal abscesses left untreated result in a very high mortality rate [l-3]. The refinement of ultrasound techniques and the advent of 67gallium citrate scanning and computed tomography (CT) have sig-

From the Departmentsof Radiology (R.P.G.,J.W.R.Y., N.S.C.), Pathologv (J.F.V.), and Surgery (H.D.R.), Medical University of South Ciroiina, CharlestonAddressreorint reauests to Rolf P. Gobien, M. D., Department of Radiology,Medical University of South Carolina, 17; Ashley Avenue, Charleston, SC 29425. Received 1982; accepted March 10, 1982. 0 1982 by Elsevier Science Publishing Co., Inc. 52 Vanderbilt Ave.. New York, NY 10017 0149-936X/82/020127-07$2.75

REINES

nificantly increased the radiologist’s ability to detect them. The recent literature contains many articles dealing with the diagnostic sensitivity and specificity of these modalities [4-g].Although some authors report the accuracy of these methods individually or in combination to approach 100% considerable false positive and false negative results have been reported and must be taken into consideration when dealing with the individual patient. The high mortality rate caused by undrained abscesses must be weighed against the risks of surgery in patients who are already debilitated. Early reports in the literature have shown the feasibility of percutaneous thin needle aspiration biopsy (TNAB) for diagnosis of abdominal masses [lo-131. Although initially performed to rule out neoplasm, TNAB has more recently been employed to verify abscess [14, 151. Several investigators [1622] have issued reports showing extension of this procedure to achieve nonoperative percutaneous catheter drainage in selected cases. Several methods of obtaining access and drainage of abscesses have been reported, but many questions of technique are as yet unanswered. The objective of this paper is to report our experience with this method to date and to attempt to point out those areas which need further study.

PATIENT

POPULATION

In the past year, 20 patients have been referred for percutaneous aspiration and possible drainage of suspected intraabdominal abscess. All patients had TNAB of their lesion, which verified the presence of purulent material. Sixteen had subsequent percutaneous drainage. Clinical data and imaging studies are presented

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in Table 1. The patients ranged in age from 28 to 68 years. Twelve had prior abdominal surgery. All had clinical and imaging data suggestive of abscess. Six lesions were intrahepatic, four infrarenal, two associated with the pancreas, three adjacent but not within the liver, two in the left upper quadrant, and

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two in the lower abdomen. The CT scans were performed on a GE 8800 CT/T scanner. The patients were supine for the initial diagnostic scans. The abdomen was scanned from diaphragm to symphysis at l- or 2-cm intervals with a lo-mm slice thickness. Scan time was either 2.4 or 4.8 sec. Oral water sol-

TABLE 1. Clinical and Imaging Data Patient number 1

64/F

Prior

History

Age/Sex Multiple,

trauma,

Pyrexia

surgery”

1152 postsuture

CT Scan

of liver

2 X 4 cm mass intrahepatic

laceration 2

48/F

Abdominal

mass,

3

41/F

Upper abdominal Pyrexia

4

68/F

5

Pyrexia

None

6 x 6 cm mass intrahepatic

pain,

li12 postcholecystectomy

3 X 4 cm mass infrahepatic

Abdominal pain, Deep venous thrombosis

None

3 x 4 cm mass of pancreas.

head

38/F

Endometriosis, Hematuria. Right flank pain

6/12 post-TAH

3 x 4 cm mass infrarenal

right

6

65/M

Alcoholism, pain

None

7 x 9 cm mass

LUQ

7

28/M

Multiple

8

53/M

Paraplegia, calculus,

9

35/F

CA ovary,

Post-op

10

64/M

Abdominal

mass,

Pyrexia

None

5 X 7 cm mass intrahepatic

11

63/M

Abdominal

mass,

Pyrexia

None

12 X 12 cm mass

12

53/M

Peripheral Infected

13

42/M

Abdominal

pain,

14

39/M

Abdominal

adhesion

15

34/F

Pancreatitis, Pyrexia

16

5oiM

Gun shot wound

Splenectomy, Closure stomach laceration

17

42/M

Renal failure, pyrexia

Open

18

65/F

Multiple

19

67/M

Obstructive Infected

20

67/F

CA ovary, Small obstruction

Pyrexia,

trauma,

LUQ

Pyrexia

Right renal Sepsis pyrexia

1:52 post splenectomy drainage hematoma

and

None

j!52

5 x 8 cm LUQ mass

9 X 10 cm mass right infrarenal post-TAH

and BSO

8 x 8 cm mass pelvis

right

intrahepatic vascular dx. stump, Pyrexia Pyrexia

Pseudocyst,

Post-op

Bilateral

BKA

jaundice. pseudocyst bowel

5 X 7 cm mass intrahepatic

Laparotomy with of liver abscess

drainage

3 X 5 cm mass intrahepatic

Lysis of adhesions, Gastrojejunostomy

6 X 8 cm mass infrahepatic

l/12

5 X 10 cm mass anterior to liver

postcholecystectomy

renal

5112 post

trauma

of

biopsy

4 X 4 cm mass infrarenal

splenectomy

Percutaneous drainage

as fractions of year; e.g. VU = I month, 3%~ = 3 weeks. TAH, total abdominal hysterectomy; LUQ. left upper quadrant;

BSO. salpingo-oophorectomy;

left

6 X 18 cm mass right infrarenal

biliary

Ileocolostomy, Anastonmotic

8 X 10 cm left subphrenic

10 X 10 cm mass tail of pancreas 2 x 3 cm mass

leak

aTime units expressed Abbreviations:

2

BKA, below

knee amputation

RLQ

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uble contrast was given to opacify the bowel. Intravenous contrast enhancement was employed during the initial diagnostic scan but not during the TNAB or drainage procedure. METHODS AND MATERIALS Technical aspects of the procedures have been previously described in detail by others [22, 231 and our method is very similar. Briefly it is as follows. TNAB of the lesion is accomplished after choosing an image showing the lesion and an optimal approach to it. The entry point and needle path are determined by selecting the shortest distance from the skin, avoiding large vascular structures and structures not involved by the infection, avoiding the costophrenic sulci, and attempting to remain retroperitoneal. It is not always possible to adhere to all the above guidelines owing to lesion location. The entry angle of the aspiration needle (22 gauge Chiba, Cook, Inc.) is measured from a scan image obtained just prior to TNAB. The desired depth of penetration is similarly measured and marked on the needle with sterile tape. The entry point is marked on the patient’s skin (different CT scanners have various methods of internal and external slice localization), and the area is prepared and draped in surgical fashion. Following local anesthesia, an 18 gauge standard needle is inserted through the skin and the subcutaneous tissue at the entry angle. Repeat scan with this marker needle in place verifies the entry point and choosen approach angle (Figure 1A). The marker needle is then removed. A stab incision with a pointed scalpel blade is made and the aspiration needle inserted through this incision at the predetermined angle to the depth previously marked by tape. Aspiration of purulent material or repeat scan (Figure 1B) verifies the location of the needle tip within the lesion. At this point technique varies depending on whether TNAB alone or subsequent percutaneous drainage is to be carried out. TNAB alone involves the aspiration of as much purulent material from the lesion as can be obtained. This material is submitted for cytologic examination, as well as culture and bacteriologic examination. The procedure is completed by repeat CT scan of the lesion to assess any decrease in size or other change. If the purulent material is too viscous to aspirate through the X&gauge needle or if the abscess cavity is immediately adjacent to the abdominal wall, a larger caliber 18-gauge Teflon sheathed needle is initially employed (Becton-Dickinson, Rutherford, NJ). When the patient is considered a candidate for

FIGURE 1. (A) Scan through liver abscess in patient 2. Note marker needle at entry site. (B) Repeat scan verifying aspiration needle in center of abscess cavity. Note that the peritoneal cavity has been traversed and that no safe approach would allow gravity or dependent drainage.

percutaneous drainage, only that amount of material required for cytologic and bacteriologic examination is removed. Aspiration of a larger amount would decrease lesion size and render the next step more difficult. The percutaneous drainage procedure itself is carried out by one of two methods dictated by the location of the abscess. If its location is immediately adjacent to the muscular layers of the body wall, a large drainage tube is employed. We use an Ochsner Trochar System (J.Skla.r Mfg., Long Island City, NY) ranging in size from 14F to 28F (French) through which we can place a soft rubber catheter ranging in size from 10F through 22F. The stab incision is extended to accept the trochar, and

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blunt dissection through the subcutaneous tissue is made. The desired depth is marked on the trochar with tape. A gentle circular motion is employed to insert the trochar to this depth. The rubber drainage tube is then inserted through the trochar. After aspiration of all purulent material the patient is rescanned to assess the size of the lesion (Figure 2A, B). If access to the lesion entails traversing the peritoneal cavity or organs such as the liver and kidney, a modified angiographic technique is used. The lesion is retapped with the teflon sheathed needle. Position of the sheath is verified by aspiration of purulent material or injection of a small amount of dilute contrast and by repeat CT scan. Under fluoroscopic control an angiographic guidewire is placed into the lesion and the sheath exchanged for a multisidehole soft angiographic catheter. We employ an 0.035~in wire followed by a 8.3F Pigtail configuraFIGURE 2. (A)

Scan through left upper quadrant abscess in patient 7. Computer measures 4.29 cm from proposed entry site to center of cavity. (B) Repeat scan following insertion of 18F drainage tube and aspiration of cavity contents. Note that location of ribs prevents more optimal lateral approach. The proxmity of bowel loops is only fully appreciated following drainage of the cavity.

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tion catheter. Following the placement of drainage tubes by the above methods, the abscess cavities are intermittently irrigated and left to drain freely. RESULTS

The results of this investigation are summarized in Table 2. Twenty patients form the basis of this study. A final diagnosis was achieved in all cases during their hospitalization and confirmed by surgery or adequate clinical and imaging follow-up. Four patients had TNAB alone (patients l-4). Of these, two were elected to undergo surgical drainage and two received only antibiotic therapy. In the latter two, TNAB combined with antibiotics proved to be curative. Sixteen patients had TNAB followed by percutaneous drainage, 5 by direct (patients 5-9) and 11 by the angiographic methods (patients 10-20). Four patients in this group subsequently had surgery. A resolved abscess was found in two of them, one of whom died of pulmonary embolus 2 weeks after surgery. The third patient underwent surgery which revealed adenocarcinoma with a necrotic center. A fourth patient had an anastomotic leak requiring surgical intervention. Twelve patients had percutaneous drainage without subsequent surgery. The drainage tube remained in place an average of 3.4 weeks. The decision as to when to remove the drains was based on the clinical appearance of the patient, the appearance of clear drainage from the tube, and radiographic evidence of a shrinking cavity. DISCUSSION

TNAB and percutaneous drainage of abdominal abscess is an extension of methods previously employed for the identification of unknown solid masses. CT is thought to be the optimum modality for localization and guidance in biopsy techniques of abdominal masses [21, 22, 241. The method represents an amalgamation of the techniques and lessons learned from angiography, percutaneous cholangiography, biliary and ureteric stent placement, and various other interventional techniques. Knowledge and experience with these methods must be combined with an understanding of surgical principles if success is to be achieved. The first objective was to establish the diagnosis. CT-guided TNAB does this with minimal patient risk. The CT image allows simultaneous visualization of the lesion and needle tip. It facilitates choosing the line of approach in order that vital structures such as liver, spleen, kidney, and large vessels may often

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TABLE 2. Methods Patient number

131

and Results TNAB

Needle

Percutaneous Approach

Method

drainage Drain size

Long-term follow-up”

1

22G

Anterior

2/12 resolved on antibiotic therapy

2

22G

Anterior

Surgical drainage, Antibiotics, 6/52 resolved

3

22G

Anterior

Surgical drainage, Antibiotics, 2/12 resolved

4

22G

Anterior

4/12 resolved

on antiobiotic

therapy 5

22G

Posterior

Direct

16F

2/12 tube removed, Resolved

6

18G

Posterior

Direct

16F

6152 tube removed,

Resolved

7

18G

Anterior

Direct

18F

6152 rube removed,

Resolved

8

18G

Lateral

Direct

18G

l/52 surgery, Resolved abscess

9

22G

Anterior

Direct

16F

2/52 surgery, Resolved abscess, 4152 death, pulmonary embolus

10

22G

Anterior

Angiographic

8.3F

2152 CT unchanged, adenocarcinoma

11

18G

Anterior

Angiographic

8.3F

2/52 tube fell out, Resolved

12

18G

Posterior

Angiographic

8.3F

3152 tube removed, Resolved

13

18G

Lateral

Angiographic

8.3F

4152 tube removed, Resolved

14

18G

Anterior

Angiographic

8.3F

5/52 resolved

Surgery:

on drainage

15

18G

Anterior

Angiographic

8.3F

2/52 tube removed, Resolved

16

22G

Lateral

Angiographic

8.3F

4152 tube removed, Resolved

17

22G

Lateral

Angiographic

8.3F

4152 tube removed, Resolved

18

18G

Lateral

Angiographic

8.3F

2152 tube removed,

19

22G

Lateral

Angiographic

8.3F

3152 died, upper GI hemorrhage, CA pancreas at autopsy

20

18G

Lateral

Angiographic

8.3F

1152 continued pyrexia. Surgery. Abscess drainage

Resolved

‘Time units expressed as fractions of year. e.g., ?k = 1 month, VU = 3 we&s

be avoided. It may make the avoidance of the peritoneal cavity possible thereby minimizing the risk of peritonitis. The 22-gauge aspiration needle employed has been shown through clinical application and animal research to be relatively atraumatic. A significant number of abscess cavities were found to contain material too viscous to aspirate through the 22-gauge needle. We have now modified the technique and use a 1.2-mm needle initially. This avoids having to retap lesions. Once the diagnosis is established the patient is assessed for possible percutaneous drainage. This decision is made jointly between radiologist and surgeon, each of whom must understand the capa-

bilities and limitations of the other. The location, size, and configuration of the abscess determine the optimal method of percutaneous drainage. The method that allowed for the placement of the largest drain while putting the patient at least risk was employed. Lesions high in the abdomen carry the risk of pneumothorax and empyema [17]; while those bordering the peritoneal cavity carry the risk of peritonitis. The correct approach to a lesion and accurate needle tip placement can minimize the possibility of these complications. If the liver, kidney, or other organs must be traversed in obtaining drainage, there is the risk of bleeding or the spread of infections to these organs. This was reduced by se-

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letting an angiographic rather than the direct approach. Ideally the most dependent portion of an abscess should be tapped and the catheter placed to allow dependant drainage. This was not always possible because of the location of the cavity (Figure 1) to intervening structures, such as bone or even adjacent bowel loops (Figure 2). The rare necrotic tumor occurring in this clinical situation may not initially be diagnosed [17,18, 221. Patient 10 is an example of this situation. The illdefined margins of the lesion seen at initial CT scan aroused suspicion of neoplasm (Figure 3).Careful cytopathologic scrutiny of samples taken at TNAB from the periphery as well as the center of this lesion [25] failed to reveal any evidence of malignancy. Failure of resolution of symptoms on drainage and of residual mass effect on repeat CT scan prompted surgical intervention, at which time a diagnosis of adenocarcinoma was made. The alternative of repeat TNAB was not elected by the patient’s attending physicians. The present study and the limited number of other studies show that nonoperative percutaneous diagnosis and drainage of abdominal abscesses can often be achieved. Although no significant complications directly attributable to the procedure were encountered in this study, considering the general clinical status of these patients, some may be expected. The possible risks of this procedure must be weighed against the demonstrated gain and balanced with the known risks and complications of surgery. We agree with Welch [26]that surgeons must be involved in each of these procedures. Not all abFIGURE 3. Initial scan of suspected liver abscess in patient 10.Permeative pattern and ill-defined margins aroused suspicion of malignancy.

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scesses will be successfully drained by this method. The decision to intervene surgically requires close observation coupled with a knowledge of the expected time course of resolution following percutaneous drainage. Patient 20 remained symptomatic despite establishment of drainage. Failure of adequate drainage in the presence of abscess communicating with bowel or other hollow organs has also been the experience of others [22] and timely surgical drainage was instituted. Several questions concerning methods of drainage remain to be answered. What is the optimal size drainage tube? Surgical experience has shown that larger tubes drain more adequately and sump-type tubes are even more effective. This has resulted in a gradual shift from smaller angiographic catheters to larger ones and even sump tubes [22]. Neither our data nor any that we are aware of demonstrate that this is the case. Drainage of intraabdominal abscesses with 7F and 8F catheters seems to contradict surgical principles, but it works. Changing to larger and considerably more expensive tubes may or may not be indicated. Several problems arise concerning catheter care. Should the catheter be irrigated? Most authors in the recent literature [16, 18, 21, 221 agree that the catheters should be intermittantly injected to keep them open. There is no agreement, however, on how often and how much irrigant to use. Others feel that any irrigation or even sinography is unnecessary and may induce sepsis or bacteremia [27]. Vigorous irrigation has been advocated as a method of lowering the viscosity and inducing better drainage by some; others consider extremely viscous contents a relative contraindication to the procedure, or advocate larger drainage tubes, or even surgery at the earliest possible time [18, 231. We presently empty the cavity initially as best we can, gently irrigate with saline until the return is clear, then irrigate four times a day with 5-lo-ml aliquots just to keep the tube from clogging. Another unanswered question concerns the optimal duration of drainage. When should the catheter be pulled out? There is uniform agreement that one should wait for complete resolution of the patient’s symptoms and signs of infection. Although some would wait for complete resolution of the cavity [16, 21, 271,others state that only scant clear drainage and evidence of a shrinking cavity [22] is required. This is not a moot point since considerable hospitalization and other costs are at stake. Two authors [18,221 have reported recurrence rates of 25% and 10.9% respectively. Whether there is a relationship between the appearance of the cavity or the catheter

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placement time and the recurrence rate has yet to be determined. This issue is made further complex by our experience (patient 11)and that of others [16] where early accidental dislodgement of the catheter did not interfere with the success of the treatment. Also in patients 1 and 4, and in other reports in the literature [15,19, 28,291,larger series of intrahepatic abscesses were treated with closed aspiration and antibiotics alone without catheter placement. Perhaps intrahepatic abscesses should be treated entirely differently. Initial success in severely ill nonsurgical candidates has changed skepticism in referring physicians to welcome acceptance. The result has been the application of percutaneous drainage to a wider range of patients. More data should be reported before dogmatic statements regarding optimal methodology can be made. Important questions concerning what size and nature of drainage tube as well as the optimal care for this tube have yet to be answered. The true benefit of the percutaneous method, correctly and carefully applied by radiologists and surgeons in close contact with one another, is that it is not harmful. The worst that could happen is surgical drainage which would have been necessary without this application. Considering the relative safety of modern surgical technique, there is very little need to be overly aggressive with the percutaneous method in most circumstances.

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2. Filly RA: Detection of abdominal abscesses: a combined approach employing ultrasonography, computed tomography and Gallium-67 scanning. J Can Assoc Radio1 30:202-210, 1979 3. Halbner MD, Daffner RI-I, Morgan CL, Trought WS, Thompson WM, Rice RP, Korobkin M: Intra-abdominal abscess: current concepts in radiologic evaluation, AJR 133:9-13, 1979 4. Aronberg DJ, Stanley RJ, Levitt RG, Sage1 SS: Evaluation of abdominal abscess with computed tomography. J Comput Assist Tomogr 2:384-387, 1978 5. Biello DR, Levitt RG, Melson GL: The roles of Gallium-67 scintigraphy, ultrasonography and computed tomography in the detection of abdominal abscess. Semin Nucl Med 9:5865, 1979 6. Callen PW: Computed tomographic evaluation of abdominal and pelvic abscesses. Radiology 131:171-175, 1979 7. Koehler PR, Moss AA: Diagnosis of intra-abdominal and pelvic abscesses by computerized tomography. JAMA 244:4852, 1980 8. Rubinson HA, Isikoff MG, Hill MD: Diagnostic imaging of hepatic abscesses: A retrospective analysis. AJR 135:735-740, 1980

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Wolverson MK, Jagannadharau B, Sundaram M, Joyce PF, Riaz MA, Shields JB: CT as a primary diagnostic method in evaluating intra-abdominal abscess. AJR 133:1089-1095, 1979

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Tao LC, Pearson FG, Delarue NC, Langer B, Sanders DE: Percutaneous fine-needle aspiration biopsy I. Its value in clinical practice. Cancer 45:1480-1485, 1980

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by computed tomography. Radiology 118:603-607, 1976 12. Haaga JR, Reich NE, Havrilla TR, Alfidi RJ: Interventional CT scanning. Radio1 Clin North Am 15:449-456, 1977 13. Ferruci JT, Wittenberg J: CT biopsy of abdominal tumors: Aids for lesion localization. Radiology 129:739-744, 1978 14. Conrad MR, Sanders RC, Mascardo D: Perinephric abscess aspiration using ultrasound guidance. AJR 128:459-464, 1977 15. McFadzean AJS, Chang KPS, and Wong CC: Solitary genie abscess of the liver treated by closed aspiration antibiotics. Br J Surg 41:141-142, 1953

proand

16. Gerzof SG, Robbins AH, Birkett DH, Johnson WC, Pugatch RD, Vincent ME: Percutaneous catheter drainage of abdominal abscesses guided by ultrasound and computed tomography. AJR 133:1-8, 1979 drain17. Gronvall J, Gronvall S, Hegedus V: Ultrasound-guided age of fluid-containing masses using angiographic catheterization techniques. AJR 129:997-1002, 1977 18. Haaga JR, Weinstein AJ: CT-guided percutaneous aspiration and drainage of abscesses. AJR 135:1187-1194, 1980 19. Novy SB, Wallace S, Goldman AM, Ben-Menachem Y: Pyogenie liver abscess: angiographic diagnosis and treatment by closed aspiration. AJR 121:388-395, 1974 20. Stephenson TF, Guzzetta LR, Taguliano OA: CT-guided Seldinger drainage of a hepatic abscess. AJR 131:323-324,1978 21. Martin EC, Karlson KB, Fankuchen EL, Cooperman rella WJ: Percutaneous drainage of postoperative dominal abscesses. AJR 138:13-15, 1982

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22. van Sonnenberg E, Ferruci JT, Mueller PR, Wittenberg J, Simeone JF: Percutaneous drainage of abscesses and fluid collections: Technique, results and applications. Radiology 142:110, 1982. 23. Gerzof SG, Robbins AH, Birkett: Computed tomography in the diagnosis and management of abdominal abscess. Gastrointest Radio1 3:287-294, 1978 24. Staab EV, Jacques PF, Partian CL: Percutaneous biopsy in the management of solid intra-abdominal masses of unknown etiology. Radio1 Clin North Am 17:435-459, 1979 25. Gobien RP, Skucas J, Paris BS: CT assisted fluoroscopically guided aspiration biopsy of central hilar and mediastinal masses. Radiology 141:443-447, 1981 26. Welch CE: Catheter drainage of abdominal abscesses. N Engl J Med 305:694-695, 1981 27. Johnson WC, Gerzof SG, Robbins AH, Nabseth DC: Comparative evaluation of operative drainage versus percutaneous catheter drainage guided by computed tomography or ultrasound. Ann Surg 194:510-520,198l 28. Berger LA, Osborne DR: Treatment of liver abscess by percutaneous needle aspiration. Lancet i:132-134, 1982 29. Herbert DA, Fogel DA, Rothman J, Wilson S, Simmons F, Ruskin J: Pyogenic liver abscess: successful non-surgical therapy. Lancet i:134-136, 1982

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