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Published online before print January 25, 2002, 10.1148/radiol.2223001805
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(Radiology 2002;222:819-823.)
© RSNA, 2002

Experimental Studies

Minimizing Diaphragmatic Injury during Radio-frequency Ablation: Efficacy of Subphrenic Peritoneal Saline Injection in a Porcine Model1

Steven S. Raman, MD, David S. K. Lu, MD, Darko J. Vodopich, MD, James Sayre, PhD and Charles Lassman, MD

1 From the Departments of Radiology (S.S.R., D.S.K.L., D.J.V., J.S.) and Pathology (C.L.), University of California Los Angeles School of Medicine, 10833 Le Conte Ave, Los Angeles, CA 90095-1721. Received November 15, 2000; revision requested December 27; final revision received September 5, 2001; accepted September 24. Supported in part by Radiotherapeutics, Inc., Mountain View, Calif. Address correspondence to S.S.R. (e-mail: sraman@mednet.ucla.edu).


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
PURPOSE: To investigate if a targeted subphrenic peritoneal infusion of normal saline to separate liver from diaphragm before radio-frequency (RF) ablation could minimize or eliminate diaphragmatic injury.

MATERIALS AND METHODS: With a 2-cm-diameter, eight-prong RF needle electrode, 37 hepatic dome RF lesions were created in 10 pigs. Seventeen lesions were created before (nonsaline group) and 20 lesions after (postsaline group) intraperitoneal infusion of approximately 500 mL of normal saline. Ten nonsaline lesions were created deep (centered 1–2 cm from the liver surface) and seven superficially (centered within 1 cm of the capsule). All 20 postsaline lesions were created superficially. Helical enhanced computed tomography was performed 24–48 hours after ablation. The pigs were killed immediately, and the diaphragm was visually inspected and sectioned. Diaphragmatic injury was graded as 0, no injury; 1, injury up to one-third thickness; 2, injury to two-thirds thickness; 3, full-thickness injury. Representative grade 3 injuries and all partial injuries underwent gross and histologic analysis.

RESULTS: All 10 deep nonsaline RF lesions caused grade 0 injury. All seven superficial nonsaline lesions caused grade 3 injury. Of the 20 superficial postsaline lesions, 13 (65%) caused grade 0 injury; four (20%), grade 1; and three (15%), grade 3. The postsaline group caused significantly less diaphragmatic injury (P < .05).

CONCLUSION: Intraperitoneal saline infusion may reduce the frequency and severity of diaphragmatic injury when adjacent liver is treated with RF ablation.

© RSNA, 2002

Index terms: Animals • Diaphragm, injuries, 795.1299 • Liver neoplasms, therapy, 761.1299 • Radiofrequency (RF) ablation, 761.1299


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Radio-frequency (RF) ablation is a promising technique for the treatment of hepatocellular carcinoma and hepatic metastasis. Although RF ablation is minimally invasive compared with traditional surgical resection, lesions have to be carefully chosen for RF ablation because unintended thermal injury may occur in adjacent structures such as the porta hepatis, major bile ducts, diaphragm, gallbladder, stomach, colon, and small bowel.

Investigators in some prior reports (1–8) have described unintended thermal injury with percutaneous, laparoscopic, and open intraoperative techniques. In open intraoperative RF ablation, the liver usually is extensively dissected and carefully manipulated to avoid thermal injury to surrounding structures (1). Metastatic lesions and some primary hepatocellular carcinomas are often located peripherally and adjacent to the diaphragm. Since the liver and diaphragmatic surfaces are closely apposed over a large surface area, the diaphragm may be easily injured during RF ablation of peripheral subcapsular lesions. In the course of prior studies (9) in which the effects of percutaneous RF ablation in the porcine liver were investigated, we also noticed unintended transdiaphragmatic thermal damage resulting from subcapsular lesions created at or near the liver dome. While performing clinical percutaneous RF ablation of peripheral lesions adjacent to the diaphragm, we have sometimes noted that patients experience local and referred (right shoulder, right arm) pain. McGahan and Dodd (7) reported a case of long-term pain attributed to post–RF ablation diaphragmatic injury. In addition to pain, thermal injuries to the diaphragm may leave a scar leading to diaphragmatic weakening and an increased but theoretic risk of rupture during subsequent blunt abdominal trauma. Ablation of a lesion apposed to the central diaphragmatic tendon also may lead to inadvertent damage to the phrenic nerve, possibly compromising diaphragmatic function. Livraghi et al (8) reported a case of post–RF ablation diaphragmatic paresis. Thermal ablation of lesions near the diaphragmatic surface has a theoretic risk of injuring lung, pericardium, and the heart.

We hypothesized that if the liver could be percutaneously separated from the diaphragm when a liver surface mass undergoes percutaneous RF ablation, such injuries may be prevented or minimized. Therefore, the purpose of our study was to investigate if a targeted subphrenic peritoneal infusion of normal saline used to separate the liver from the diaphragm before RF ablation could minimize or eliminate diaphragmatic injury.


   MATERIALS AND METHODS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
RESULTS
 DISCUSSION
 REFERENCES
 
As part of a broader study investigating RF ablation in the in vivo porcine liver, approval was obtained from the animal institutional review board for this component of the overall study. This study was performed between June 1999 and February 2000. Ten Yorkshire pigs weighing an average of 34 kg were used, and all procedures were performed with animals under general anesthesia. Induction was achieved with use of an intramuscular injection of 150 mg of ketamine hydrochloride (Ketaset; Animal Health, Fort Dodge, Iowa) and 150 mg of xylazine (Xylazine-100; Butler, Columbus, Ohio). The animals were intubated, and 5 L/min of 5% endotracheal halothane (Fluothane; Halocarbon Laboratories, River Edge, NJ) was administered.

The pigs were placed in the supine position after adequate anesthesia was achieved; the right upper quadrant and epigastrium were shaved, and the surface was sterilized. Both thighs were shaved, and grounding pads were placed bilaterally. Transverse and longitudinal ultrasonographic (US) evaluation (SSH-140, Toshiba, Toshigi-Ken, Japan; HDI-3000 and HDI-5000, Advanced Technology Laboratories, Bothell, Wash) of the liver was performed (S.S.R., D.S.K.L., D.J.V.), and hepatic parenchyma within 2 cm of the capsule near the liver dome (adjacent to the diaphragm) was chosen for ablation. Every attempt was made to avoid areas adjacent to visualized intrahepatic fissures; we realized from prior work (9) that lesions within or adjacent to fissures become distorted, often losing their spherical or ovoid shape.

A 15-gauge RF probe (LeVeen needle electrode; Radiotherapeutics, Sunnyvale, Calif) was used. This needle electrode is equipped with eight retractable curved distal prongs, which, when fully expanded, assume an umbrella shape 2 cm in maximum diameter perpendicular to the axis of the probe (Fig 1). The probe was advanced into the hepatic parenchyma, and the prongs were deployed in appropriate superficial (0–1 cm) or deep (1–2 cm) locations by at least two of the authors (S.S.R., D.S.K.L., D.J.V.). A 90-W monopolar RF generator (RF 2000; Radiotherapeutics) was used as the energy source. Power output was initially set at 30 W and titrated manually upward to maintain maximal power without rise in impedance for at least 5 minutes. Thereafter, impedance was allowed to increase, with automatic power adjustment, until power output was terminated. The average time for lesion creation was 7.8 minutes (range, 6–11 minutes).



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  		Figure 1. Photograph of 3-cm 10-prong (A) and 2-cm eight-prong (B) LeVeen needles. The 2-cm needle was used in this study.

 
For saline infusion, the plane between the peritoneum and liver capsule was gently localized with a 22-gauge Chiba needle (Cook Group, Bloomington, Ind), which was inserted via a subxiphoid approach by one of the authors (S.S.R., D.S.K.L., D.J.V.). Approximately 5 mL of 1% lidocaine (Xylocaine-MPF; Astra USA, Westborough, Mass) was injected into the perihepatic space, separating the liver from the peritoneum. The 22-gauge needle was withdrawn, and an 18-gauge Chiba needle (Cook Group) was inserted under US guidance into the freshly created pocket of lidocaine. Approximately 500 mL (500–1,000 mL) of sterile normal saline was then introduced into the subphrenic space by means of gravity infusion to achieve at least 1 cm of separation between the liver and the diaphragmatic surface (Fig 2). As the liver progressively moved away from the diaphragmatic surface, the needle could be redirected in multiple planes to help separate other areas of liver from the diaphragm. In general, maximal separation was achieved at the anterior and anterolateral hepatic surfaces. Relatively less separation was achieved posteriorly near the bare area. The volume of saline lasted approximately 10–20 minutes before dissipation. In two of five animals, saline dissipated into the peritoneal cavity within 10 minutes, and additional 100–200-mL aliquots of saline (maximum, 1,000 mL) were infused to maintain at least a 1-cm separation between the liver and the diaphragm.



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  		Figure 2a. (a) Longitudinal oblique US scan shows that normal saline (S) instillation into the subphrenic space results in at least 1-cm separation of the liver (L) posteriorly and caudally from the diaphragm (D). (b) Longitudinal oblique US scan shows the LeVeen needle (straight arrows) with the prongs deployed (curved arrows). (c) Longitudinal oblique US scan shows the LeVeen needle and the characteristic hyperechoic cloud (arrows) present toward the end of the second ablation session.

 


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  		Figure 2b. (a) Longitudinal oblique US scan shows that normal saline (S) instillation into the subphrenic space results in at least 1-cm separation of the liver (L) posteriorly and caudally from the diaphragm (D). (b) Longitudinal oblique US scan shows the LeVeen needle (straight arrows) with the prongs deployed (curved arrows). (c) Longitudinal oblique US scan shows the LeVeen needle and the characteristic hyperechoic cloud (arrows) present toward the end of the second ablation session.

 


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  		Figure 2c. (a) Longitudinal oblique US scan shows that normal saline (S) instillation into the subphrenic space results in at least 1-cm separation of the liver (L) posteriorly and caudally from the diaphragm (D). (b) Longitudinal oblique US scan shows the LeVeen needle (straight arrows) with the prongs deployed (curved arrows). (c) Longitudinal oblique US scan shows the LeVeen needle and the characteristic hyperechoic cloud (arrows) present toward the end of the second ablation session.

 
To evaluate the results of RF lesion creation, segregate lesion proximity with respect to hepatic surface, and evaluate for complications such as intraperitoneal hemorrhage, each animal underwent contrast material–enhanced helical computed tomography (CT) (CTi; GE Medical Systems, Milwaukee, Wis) 24 (five animals) or 48 (five animals) hours after ablation. Animals could not be imaged at exactly the same time after RF ablation because of constraints in the scheduling of CT and availability of animal laboratory personnel. The pigs were sedated for CT imaging by using only the induction anesthesia protocol just discussed. (The animals were not intubated for CT, and respiration was not suspended.) After initial nonenhanced images of the liver were obtained, 40 mL of iohexol (Omnipaque 350; Nycomed, Princeton, NJ) was power injected at 3 mL/sec with use of the following CT parameters: 250 mAs, 120 kV, 3-mm collimation, and a pitch of 2:1. Images were acquired in the portal venous phase (60-second delay).

A total of 37 hepatic RF lesions were created in 10 pigs. Two to six lesions were created according to the following distribution: two lesions in three animals, three lesions in one animal, four lesions in two animals, five lesions in three animals, and six lesions in one animal. The lesions were classified into two groups: those created without saline infusion (nonsaline) and those created after saline infusion (postsaline). With use of the CT scan and pathologic examination, these lesions were further stratified according to their relative proximity to the hepatic surface by three of the authors (S.S.R., D.S.K.L., D.J.V.). The lesions were, therefore, subcategorized as those centered within 1 cm of liver surface (superficial) and those centered 1–2 cm from the liver surface (deep) (Fig 3). On the basis of prior work (9), the lesions were generally expected to be spherical or slightly ovoid and to have an average diameter of approximately 2.0 cm (2.0 cm radial diameter of the fully deployed prongs), with a radius of 1 cm. As observed previously (9), lesions closely apposed to the hepatic surface (superficial lesions) were expected to have more variable contours.



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  		Figure 3a. (a) Transverse contrast-enhanced helical CT scan shows a representative superficial RF lesion (arrow) high at the dome and centered within 1 cm of the hepatic surface. (b) Transverse contrast-enhanced helical CT scan shows a representative deep RF lesion (arrows) centered more than 1 cm from the hepatic surface. The stomach (st) is partially visible.

 


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  		Figure 3b. (a) Transverse contrast-enhanced helical CT scan shows a representative superficial RF lesion (arrow) high at the dome and centered within 1 cm of the hepatic surface. (b) Transverse contrast-enhanced helical CT scan shows a representative deep RF lesion (arrows) centered more than 1 cm from the hepatic surface. The stomach (st) is partially visible.

 
In the nonsaline group, 10 deep and seven superficial lesions were created. In the postsaline group, we intentionally created 20 superficial lesions because we assumed superficial lesions were more likely to create diaphragmatic injury than were deep ones. In the 10 animals, 13 nonsaline lesions (10 deep, three superficial) were created in five animals. Four single superficial nonsaline lesions were created in each of four animals (total, 17 nonsaline lesions). Intraperitoneal saline was subsequently infused in each of these four animals, and 14 superficial postsaline lesions were created. In the 10th animal, six superficial postsaline lesions were created (total, 20 postsaline lesions).

The pigs were killed immediately after CT, and at postmortem examination, the diaphragmatic surface adjacent to the lesions was inspected and photographed by three of the authors (S.S.R., D.S.K.L., D.J.V.). The diaphragm was considered to be injured if a discolored, thickened pale area was seen extending toward the pleural margin from the peritoneal margin. Areas of suspected diaphragmatic injury were sectioned and graded on a scale of 0–3: 0, no diaphragmatic injury; 1, mild injury up to one-third thickness; 2, moderate injury to two-thirds thickness; and 3, severe full-thickness injury. A representative gross specimen of injured diaphragm and five samples of grossly uninjured diaphragm were sectioned for histologic correlation by a single pathologist (C.L.). Histologically, we evaluated for the proportion of cross-sectional injury by assessing for the concentric trilaminar pattern of thermal injury (inner necrotic zone, hemorrhagic red rim, and outer pale rim) described previously (9). Of the grade 3 injuries, six lesion samples (three nonsaline and three postsaline lesions) were analyzed histologically. All partial injuries (grades 1 and 2) were correlated with histologic findings to ensure grading accuracy. The RF lesions in the liver were also sectioned.

The groups were compared with respect to the severity of diaphragmatic injury, and the significance of the difference was determined by using a generalized estimating equation (10). A P value of less than .05 was considered to indicate a statistically significant difference.


   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
DISCUSSION
 REFERENCES
 
All 37 lesions had some visible extension to the hepatic surface. As expected, the superficial lesions in both the nonsaline and postsaline groups produced larger and more irregular surface burns (approximately 1.5–2 cm) than those of the deep lesions (approximately 0–0.5 cm). (Size of the surface lesions was estimated and not measured owing to their expected irregular contour.) In the nonsaline group, seven of seven superficial lesions produced transdiaphragmatic injury (grade 3), whereas the 10 deep lesions produced no diaphragmatic injury (grade 0), resulting in a significantly (P < .001) higher rate of diaphragmatic injury for the superficial group (Table). Three of the seven nonsaline grade 3 lesions were confirmed (Fig 4c).


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  		Distribution and Severity of Diaphragmatic Injuries

 


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  		Figure 4a. (a) Representative grade 1 injury from a superficial postsaline lesion. Gross cross section through the central tendon of the diaphragm shows well-demarcated thermal injury (arrows) that extends to one-third thickness. Pl = uninjured parietal pleural surface, Pe = injured peritoneal surface. (b) Photomicrograph of diaphragmatic section with typical grade 1 injury. Peritoneal injury (arrows) is present. 1 = uninjured diaphragmatic muscle, 2 = hemorrhagic and inflammatory rim, 3 = coagulative necrosis of muscle tissue. (Hematoxylin-eosin stain; original magnification, x100.) (c) Representative grade 3 injury from a superficial nonsaline lesion. Gross cross section through the thick central tendon of the diaphragm shows a well-defined, variably pale ovoid region of thermal injury extending through the diaphragm from the peritoneal surface (Pe) to the pleural surface (Pl). The parietal pleura and peritoneum (not shown) were injured.

 


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  		Figure 4b. (a) Representative grade 1 injury from a superficial postsaline lesion. Gross cross section through the central tendon of the diaphragm shows well-demarcated thermal injury (arrows) that extends to one-third thickness. Pl = uninjured parietal pleural surface, Pe = injured peritoneal surface. (b) Photomicrograph of diaphragmatic section with typical grade 1 injury. Peritoneal injury (arrows) is present. 1 = uninjured diaphragmatic muscle, 2 = hemorrhagic and inflammatory rim, 3 = coagulative necrosis of muscle tissue. (Hematoxylin-eosin stain; original magnification, x100.) (c) Representative grade 3 injury from a superficial nonsaline lesion. Gross cross section through the thick central tendon of the diaphragm shows a well-defined, variably pale ovoid region of thermal injury extending through the diaphragm from the peritoneal surface (Pe) to the pleural surface (Pl). The parietal pleura and peritoneum (not shown) were injured.

 


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  		Figure 4c. (a) Representative grade 1 injury from a superficial postsaline lesion. Gross cross section through the central tendon of the diaphragm shows well-demarcated thermal injury (arrows) that extends to one-third thickness. Pl = uninjured parietal pleural surface, Pe = injured peritoneal surface. (b) Photomicrograph of diaphragmatic section with typical grade 1 injury. Peritoneal injury (arrows) is present. 1 = uninjured diaphragmatic muscle, 2 = hemorrhagic and inflammatory rim, 3 = coagulative necrosis of muscle tissue. (Hematoxylin-eosin stain; original magnification, x100.) (c) Representative grade 3 injury from a superficial nonsaline lesion. Gross cross section through the thick central tendon of the diaphragm shows a well-defined, variably pale ovoid region of thermal injury extending through the diaphragm from the peritoneal surface (Pe) to the pleural surface (Pl). The parietal pleura and peritoneum (not shown) were injured.

 
In 20 superficial postsaline lesions, 13 lesions (65%) caused no diaphragmatic injury (grade 0), four lesions (20%) caused minimal diaphragmatic injury (grade 1), and three lesions (15%) caused full-thickness injury (grade 3) (Fig 4a, 4b) (Table). With use of a generalized estimating equation approach (10), the superficial postsaline lesions caused significantly less (P < .05) diaphragmatic injury than did superficial lesions in the nonsaline group. The three grade 3 postsaline lesions were created early in our experience, and the saline separation between liver and diaphragm may have been marginal.

At gross inspection, a characteristic trilaminar pattern was observed in both hepatic and diaphragmatic thermal lesions. In diaphragmatic lesions, lesions in the outer pale rim were less distinct and irregular. This was confirmed histologically. In the postsaline group, all three grade 3 injuries and four grade 1 injuries were compared histologically to confirm the visual grading scheme.

No major complications occurred. No substantial intraperitoneal fluid or perihepatic hematoma was detected either clinically on the postablation CT scan (24 or 48 hours after the procedure) or subsequently at postmortem inspection during liver harvest.


   DISCUSSION
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
REFERENCES
 
During intraoperative hepatic RF ablation, the liver often is isolated from surrounding structures by a rigorous dissection and placement of laparotomy pads, thus limiting the potential for major collateral injury. However, to our knowledge, a technique to manipulate liver position percutaneously during RF ablation has not been described. In this study, we demonstrated in an in vivo porcine model that this technique is feasible and resulted in a significantly decreased number and magnitude of diaphragmatic injuries.

Traditionally, especially in the era before imaging guidance, ascites was considered a relative contraindication to percutaneous liver biopsy because of an increased risk of sustained intraperitoneal hemorrhage from the hepatic surface (11). The ascitic fluid was thought to wash away thrombogenic material at the puncture site and decrease or eliminate the "tamponade effect" from opposing parietal peritoneum against the liver. Studies in the radiologic literature (12) have challenged this assumption and have shown no significant increase in the rate of hemorrhagic complications. In our study, no major peritoneal hemorrhage was detected, even though fluid surrounded the perforation site in the hepatic capsule. This may be partly due to the inherently coagulative effect of the RF ablation procedure.

There may be other theoretic benefits to intraperitoneal saline infusion for RF ablation of tumors in the hepatic dome. Because of their location, many of these tumors may be difficult to identify or access with US or CT (13,14). Saline infusion displaces the hepatic dome caudally, and this may aid in the visualization of such lesions, especially at US. Also, separation of liver from the diaphragm may enable better depiction of those tumors that invade the adjacent diaphragm, since these lesions would likely adhere to the diaphragm. This subset of patients would be poor candidates for ablation.

Limitations of this study include the applicability of data from a porcine model to humans. The postsaline injury results may actually be an overestimate, since the three postsaline lesions causing transdiaphragmatic injury were on the anterior surface and occurred early in our experience. They likely resulted from inadequate saline separation of liver from the diaphragm. Finally, the best separation was achieved anteriorly in porcine liver. There was less overall separation posteriorly near the bare area.

In summary, we have developed a simple method to manipulate hepatic position during percutaneous hepatic RF ablation to limit diaphragmatic injury in a porcine model. We have shown that percutaneous subphrenic saline infusion may help eliminate, or at least substantially limit, the magnitude of diaphragmatic injury when RF ablation is performed on superficial subcapsular lesions adjacent to the diaphragm. Whether this technique proves useful in patients remains to be tested clinically.

Practical application: In a porcine model, we used a simple percutaneous saline infusion technique to manipulate the liver and separate it from the adjacent diaphragm. Further, we demonstrated a significant decrease in the degree of RF ablation–induced diaphragmatic injury after saline infusion. If validated clinically, this technique may prove helpful to decrease the morbidity associated with thermal ablation injury of the diaphragm.


   ACKNOWLEDGMENTS
 
The authors thank Julia Fendrick, BA, for her assistance in editing the manuscript.


   FOOTNOTES
 
Abbreviation: RF = radio frequency

Author contributions: Guarantor of integrity of entire study, D.S.K.L.; study concepts and design, S.S.R., D.S.K.L.; literature research, S.S.R., D.J.V.; experimental studies, S.S.R., D.J.V.; data acquisition, S.S.R., D.J.V., C.L.; data analysis/interpretation, S.S.R., D.S.K.L., C.L.; statistical analysis, J.S.; manuscript preparation and definition of intellectual content, S.S.R.; manuscript editing, revision/review, and final version approval, S.S.R., D.S.K.L.


   REFERENCES
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. Jiao LR, Hansen PD, Havlik R, et al. Clinical short-term results of radiofrequency ablation in primary and secondary liver tumors. Am J Surg 1999; 177:303-306.
  2. Siperstein A, Garland A, Engle K, et al. Local recurrence after laparoscopic radiofrequency thermal ablation of hepatic tumors. Ann Surg Oncol 2000; 7:106-113.
  3. Pearson AS, Izzo F, Fleming RY, et al. Intraoperative radiofrequency ablation or cryoablation for hepatic malignancies. Am J Surg 1999; 178:592-599.
  4. Dodd GD, Soulen MC, Kane RA, et al. Minimally invasive treatment of malignant hepatic tumors: at the threshold of a major breakthrough. RadioGraphics 2000; 20:9-27.
  5. Lees WR, Gilliams AR. Complications of radiofrequency and laser ablation of liver metastases: incidence and management (abstr). Radiology 1999; 213(P):509.
  6. Solbiati L, Goldberg SN, Ierace T, Livraghi T, Meloni F, Gazelle GS. Outcome and 4-year survival of patients undergoing cool-tip RF ablation for colorectal metastases (abstr). Radiology 2000; 217(P):607.
  7. McGahan JP, Dodd GD. Radiofrequency ablation of the liver: current status. AJR Am J Roentgenol 2000; 176:3-15.
  8. Livraghi T, Slobiati L, Melone F, Ierace T, Goldberg SN. Complications after cool-tip RF ablation of liver cancer: initial report of the Italian multicenter cooled-tip RF study group (abstr). Radiology 2000; 217(P):27.
  9. Raman SS, Lu DSK, Vodopich D, et al. Creation of radiofrequency lesions in a porcine model: correlation with sonography, CT, and histopathology. AJR Am J Roentgenol 2000; 175:1253-1258.
  10. Zeger SL, Liang KY, Albert PS. Models for longitudinal data: a generalized estimating equation approach. Biometrics 1988; 44:1049-1060.
  11. Perrault J, McGill DB, Ott BJ, Taylor WF. Liver biopsy: complications in 1000 inpatients and outpatients. Gastroenterology 1978; 74:103-106.
  12. Murphy FB, Barefield KP, Steinberg HV, et al. CT or sonography guided biopsy of the liver in the presence of ascites: frequency of complications. AJR Am J Roentgenol 1988; 151:485-486.
  13. Lu DS, Lee H, Farahani K, Sinha S, Lufkin R. Biopsy of hepatic dome lesions: semi-real-time coronal MR guidance technique. AJR Am J Roentgenol 1997; 168:737-739.
  14. Lu DS, Silverman SG, Raman SS. MR-guided therapy: applications in the abdomen. Magn Reson Imaging Clin N Am 1999; 7:337-348.



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RADIOLOGY RADIOGRAPHICS RSNA JOURNALS ONLINE