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EUS-Guided Drainage of Pelvic Abscess
EUS-Guided Drainage of Pelvic Abscess Shyam Varadarajulu, MD Pelvic abscesses are most commonly encountered in the setting of postoperative complications. Traditionally, these were drained by surgery or under radiological guidance. Although limited, there is growing evidence that under the guidance of endoscopic ultrasound pelvic abscesses can be drained with successful outcomes. This review describes the technical details and outcomes associated with this procedure. Tech Gastrointest Endosc 9:51-54 © 2007 Elsevier Inc. All rights reserved. KEYWORDS endoscopic ultrasound, pelvic abscess, drainage
D
evelopment of pelvic abscess is a well-recognized postoperative complication in patients undergoing low anterior resection for rectal cancer or following obstetrical surgery.1 Rupture of pelvic abscess is a life-threatening emergency, and every attempt should be made to avoid this complication. Traditionally, these abscesses are drained via the percutaneous, transrectal, or transvaginal route under ultrasound or computed tomogram (CT)-guidance with successful outcomes.1-4 The transvaginal route is ideally suited to drain pelvic abscesses because of the proximity of the vaginal fornices to the pelvic fluid collections. However, the transvaginal route has the disadvantage of being only semisterile. Hence, due to the risk of introducing infection into a previously sterile region, the transvaginal approach is generally used only for biopsy of solid lesions or for draining cystic lesions that can be completely aspirated. In a recent study, the feasibility of ultrasound-guided transrectal aspiration of pelvic abscesses was assessed in 15 women in whom intravenous antibiotic therapy had failed and whose abscesses were not suitable for colpotomy drainage or transabdominal or transvaginal ultrasound-guided aspiration.4 Purulent material was aspirated from the abscesses in 14 of the 15 women. These 14 women were successfully treated with real-time ultrasound-guided transrectal drainage, and only 4 required placement of an indwelling catheter. This report generated interest that led to the evolution of EUS-guided drainage of pelvic abscesses. This review details the technical aspects and outcomes of endoscopic ultrasound (EUS) in the management of patients with pelvic abscesses.
Division of Gastroenterology-Hepatology, University of Alabama at Birmingham School of Medicine, Birmingham, AL. Address reprint requests to Shyam Varadarajulu, MD, Division of Gastroenterology-Hepatology, University of Alabama at Birmingham Medical Center, 410 LHRB, 1530 3rd Ave S, Birmingham, AL 35294. E-mail: [email protected]
1096-2883/07/$-see front matter © 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.tgie.2006.11.016
Instruments and Materials A clear understanding of the anatomy of the pelvis and the location of the abscess is important before proceeding with pelvic drainage. In all patients, a dedicated pelvic MRI or CT imaging should be initially performed to ascertain their underlying nature and confirm that these abscesses cannot be drained by well-proven alternate techniques. The most common reason to undergo EUS-guided drainage is due to the lack of an adequate window to drain the lesion percutaneously or if the patient is a high-risk candidate for surgical drainage. Patients should be administered prophylactic antibiotics (amoxicillin plus clavulinic acid, 2 g) before the intervention and continued on oral antibiotics for 4 to 5 days. A preparation in the form of an enema and/or polyethylene glycol is mandatory to minimize the chances of contamination and for adequate visualization. Also, the procedure is best performed in a unit with fluoroscopy set up to enable
Figure 1 CT of the pelvis revealing an 8- ⫻ 7-cm abscess cavity.
51
S. Varadarajulu
52
● ● ●
Figure 2 Curvilinear EUS examination revealing a pelvic abscess measuring 8 ⫻ 7 cm and located extrinsic to the rectum.
visualization of wire exchanges and stent or drain placement within the abscess. Patients should be instructed to void urine before the procedure, as a distended bladder may impair visualization of a small pelvic abscess during EUS.
●
Echo-Endoscopes Linear array echo-endoscopes offering a working channel of at least 3 mm should be used; this includes the FG38UX (Pentax), the EG38UT (Pentax) and the GF-UCT140 (Olympus). The EG38UT and the GF-UCT140, which are used with working channels of 3.8 and 3.7 mm, respectively, both allow placement of a 10-French stent. On the other hand, the FG38X has a working channel of 3.2 mm, which only permits placement of an 8.5-French stent. These instruments are coupled with an ultrasound processor such as the Aloka (Tokyo, Japan) or the EUB6000 from Hitachi (Tokyo, Japan).
●
●
Devices A 19-gauge EUS-FNA needle (Echotip, Wilson-Cook; Vizeon, CONMED) is required to pass a 0.035-inch guide wire (X-wire, Conmed Industries) into the abscess cavity. A needle-knife (Zimmon needle knife, Wilson-Cook) catheter is required to puncture the wall of the abscess to facilitate stent or drain placement. Alternatively, in patients who are at high risk for bleeding, a standard 4.5/5-French ERCP cannula and a 10-French ERCP inner guiding catheter (WilsonCook) can be passed over the guide wire, in succession, to gradually “burrow” the wall of the abscess cavity to achieve the same effect. Biliary balloon dilator (6/8 mm) or a throughthe-scope balloon (Eliminator, Multi-stage balloon dilator, CONMED; Eclipse Dilation Balloon, Wilson-Cook) is needed to further dilate the tract between the abscess cavity and rectum. A single pigtail plastic stent (8.5- or 10-French) or drain (Flexima, Boston Scientific) is required to facilitate drainage of the abscess cavity.
●
using Doppler, under EUS-guidance, a large 19-gauge needle is used to puncture the abscess cavity to gain access to the fluid collection (Fig. 3). Normal saline is used to flush the abscess cavity using a 10-mL syringe and re-aspirated to clean out the cavity of as much pus as possible. A sample of the aspirate should be sent for gram staining and culture. A 0.035-inch guide wire is then passed via the 19-gauge needle and coiled into the abscess cavity. The puncture site of the abscess cavity is then further enlarged by introducing a needle-knife catheter through the working channel of the echoendoscope and puncturing the abscess under EUS-guidance. Alternatively, in patients who are at high risk for bleeding, a 4.5/5French ERCP cannula is passed over the guide wire to dilate the wall of the abscess cavity. This is then further dilated by passing a 10-French ERCP inner guiding catheter over the guide wire. The tract is further dilated using a 6/8-mm over the wire balloon and/or by using through-the-scope balloons (6-14 mm) (Fig. 4A and B, and Fig. 5). The presence of a large opening will facilitate better drainage of the abscess and provide easy access for future interventions. This is most suitable for patients undergoing drain placement. However, dilation beyond 6 mm is not required if the intention is to only place a stent. An 8.5- or 10-French single pigtail stent is then deployed over the guide wire into the abscess to establish complete drainage. Although straight stents may be placed, there is a theoretical risk for migration into the abscess cavity. In patients with large pelvic abscesses and those in whom a quick resolution is desired, a 10-French single pigtail drain can be placed alone or in combination with a stent (Fig. 6). The drain is flushed with 50 mL of normal saline, every 8 hours, until the abscess is completely evacuated. After verifying resolution of the abscess on follow-up CT (Fig. 7), the drain and/or stent can be removed.
Procedural Technique EUS-guided drainage of pelvic abscess is comprised of the following steps: ● ●
By performing a rectal EUS examination, the pelvic abscess is first located (Figs. 1 and 2). After ensuring the absence of intervening vasculature
Figure 3 Passage of a 19-gauge needle into the pelvic abscess under EUS-guidance to facilitate drainage.
EUS-guided drainage of pelvic abscess
53
Figure 4 (A, B) Dilation of the tract by using an 8-mm biliary balloon dilator and then to 14 mm using a through-thescope balloon dilator.
Outcomes In a study of 12 patients with deep pelvic abscesses in whom EUS-guided trans-rectal stent (8.5/10-French) placement was attempted, Giovanninni and coworkers reported a technical success rate of 75% with resolution of abscess in 8 of 12 patients.5 In 3 patients, stenting was not possible due to the distance between the abscess and the rectal wall (⬎20 mm). The mean duration of stenting was 4.3 months. With the exception of 2 patients (largest abscess measured 85 ⫻ 83 mm), others had a pelvic abscess that was smaller than 60
Figure 5 Drainage of pus into the rectum postdilation.
mm. The outcome was unsuccessful in the patient with largest abscess, and he eventually required surgical drainage. No complications were encountered in this study (Table 1). As part of an ongoing prospective study, we have performed EUS-guided drainage of pelvic abscesses in four patients that were not amenable for drainage by the percutaneous route. The mean size of the abscess in these four patients was 68 ⫻ 72 mm. All patients had successful placement of a 10-French drainage catheter into the abscess cavity under EUS-guidance. The abscesses resolved spontaneously within
Figure 6 Fluoroscopic view revealing the presence of a pigtail drain into the pelvic abscess cavity.
S. Varadarajulu
54
Which Is the Best Technique to Drain Abscesses: Stent versus Drainage Catheter Placement? Experience with EUS-guided drainage of pelvic abscesses is limited. There are no studies comparing both techniques. However, due to its small caliber, trans-rectal stents can potentially clog easily, particularly by fecal matter, and when left long-term can cause peri-rectal pain or migrate spontaneously. Placing a drainage catheter enables continued access to the abscess cavity for flushing and drainage of the infected fluid collection. Also, the chance of infecting a sterile abscess is more remote with trans-rectal drain placement than with stenting. Moreover, the drain can be removed in a shorter period of time as continued therapy will potentially resolve the abscess faster. Figure 7 Repeat CT of the pelvis at day 6, showing marked reduction in size of the abscess cavity.
a mean duration of 6 days, and there was no recurrence at 3 months follow up. Although one patient died of worsening heart failure, no procedure-related complications were encountered.
Which Is the Best Technique to Dilate the Wall of the Abscess Cavity: NeedleKnife versus “Burrowing” with Catheters? In the absence of comparative data, this question is difficult to address. Perforation has been reported as a complication during EUS-guided drainage of pancreatic pseudocysts using the needle-knife technique. It can be sometimes challenging to control the direction of the cut when using needle-knife catheters, leading to inadvertent perforation. Although this could be minimized by using an over-the-wire needle knife, the needle when deployed often points in a tangential angle due to its thin caliber leading to an undesirable incision. We routinely dilate the wall of the pancreatic pseudocyst, after gaining access with a 19-gauge needle and passing a 0.035inch guide wire, using a 4.5/5-French ERCP catheter and then using a 10-French ERCP inner guiding catheter. This facilitates easy passage of 6/8-mm biliary balloon dilators and through-the-scope balloons for further dilation of the pseudocyst wall. We have experienced no complications with this technique while managing patients with pancreatic pseudocysts and have had excellent outcomes with pelvic abscesses as well. The decision to undertake either technique should be based on expertise of the endoscopist and availability of resources.
Technical Limitations Drainage of pelvic abscess cannot be undertaken when the wall of the abscess cavity is ⬎20 mm from the EUS transducer. Also, the presence of multiple cavities in an abscess precludes successful drainage. It is important to carry out a helical CT scan before embarking on this procedure because poorly defined or multilocular fluid collections are not suitable for this nonsurgical method of drainage. EUS-guided pelvic abscess drainage must be performed only in patients with a unilocular cavity.
Conclusion EUS-guided drainage can be an effective treatment modality for management of patients with abscesses or fluid collections in the pelvis that are not amenable to conventional therapy. Comparative studies with larger numbers of patients will help identify cases that benefit the most from this technique.
References 1. Hovsepian DM: Transrectal and transvaginal abscess drainage. J Vasc Interv Radiol 4:501-515, 1997 2. Brusciano L, Maffettone V, Napolitano V, et al: Management of colorectal emergencies: percutaneous abscess drainage. Ann Ital Chir 75:593-597, 2004 3. O’Neill MJ, Rafferty EA, Lee SI, et al: Transvaginal interventional procedures: aspiration, biopsy, and catheter drainage. Radiographics 3:657672, 2001 4. Nelson AL, Sinow RM, Oliak D: Transrectal ultrasonographically guided drainage of gynecologic pelvic abscesses. Am J Obstet Gynecol 6:13821388, 2000 5. Giovanninni M, Bories E, Moutardier V, et al: Drainage of deep pelvic abscesses using therapeutic echo endoscopy. Endoscopy 35:511-514, 2003 6. Varadarajulu S, Drelichman ER. EUS-guided drainage of pelvic abscess. Gastrointest Endosc (In press)
Table 1 EUS-Guided Drainage of Pelvic Abscess Author
No. of Patients
Mean Size (mm)
Drainage mode
Technical Success (%)
Giovannini Varadarajulu6
12 4
48.9 ⴛ 43.4 68 ⴛ 72
Stenting Drainage catheter
75 100
5
D
evelopment of pelvic abscess is a well-recognized postoperative complication in patients undergoing low anterior resection for rectal cancer or following obstetrical surgery.1 Rupture of pelvic abscess is a life-threatening emergency, and every attempt should be made to avoid this complication. Traditionally, these abscesses are drained via the percutaneous, transrectal, or transvaginal route under ultrasound or computed tomogram (CT)-guidance with successful outcomes.1-4 The transvaginal route is ideally suited to drain pelvic abscesses because of the proximity of the vaginal fornices to the pelvic fluid collections. However, the transvaginal route has the disadvantage of being only semisterile. Hence, due to the risk of introducing infection into a previously sterile region, the transvaginal approach is generally used only for biopsy of solid lesions or for draining cystic lesions that can be completely aspirated. In a recent study, the feasibility of ultrasound-guided transrectal aspiration of pelvic abscesses was assessed in 15 women in whom intravenous antibiotic therapy had failed and whose abscesses were not suitable for colpotomy drainage or transabdominal or transvaginal ultrasound-guided aspiration.4 Purulent material was aspirated from the abscesses in 14 of the 15 women. These 14 women were successfully treated with real-time ultrasound-guided transrectal drainage, and only 4 required placement of an indwelling catheter. This report generated interest that led to the evolution of EUS-guided drainage of pelvic abscesses. This review details the technical aspects and outcomes of endoscopic ultrasound (EUS) in the management of patients with pelvic abscesses.
Division of Gastroenterology-Hepatology, University of Alabama at Birmingham School of Medicine, Birmingham, AL. Address reprint requests to Shyam Varadarajulu, MD, Division of Gastroenterology-Hepatology, University of Alabama at Birmingham Medical Center, 410 LHRB, 1530 3rd Ave S, Birmingham, AL 35294. E-mail: [email protected]
1096-2883/07/$-see front matter © 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.tgie.2006.11.016
Instruments and Materials A clear understanding of the anatomy of the pelvis and the location of the abscess is important before proceeding with pelvic drainage. In all patients, a dedicated pelvic MRI or CT imaging should be initially performed to ascertain their underlying nature and confirm that these abscesses cannot be drained by well-proven alternate techniques. The most common reason to undergo EUS-guided drainage is due to the lack of an adequate window to drain the lesion percutaneously or if the patient is a high-risk candidate for surgical drainage. Patients should be administered prophylactic antibiotics (amoxicillin plus clavulinic acid, 2 g) before the intervention and continued on oral antibiotics for 4 to 5 days. A preparation in the form of an enema and/or polyethylene glycol is mandatory to minimize the chances of contamination and for adequate visualization. Also, the procedure is best performed in a unit with fluoroscopy set up to enable
Figure 1 CT of the pelvis revealing an 8- ⫻ 7-cm abscess cavity.
51
S. Varadarajulu
52
● ● ●
Figure 2 Curvilinear EUS examination revealing a pelvic abscess measuring 8 ⫻ 7 cm and located extrinsic to the rectum.
visualization of wire exchanges and stent or drain placement within the abscess. Patients should be instructed to void urine before the procedure, as a distended bladder may impair visualization of a small pelvic abscess during EUS.
●
Echo-Endoscopes Linear array echo-endoscopes offering a working channel of at least 3 mm should be used; this includes the FG38UX (Pentax), the EG38UT (Pentax) and the GF-UCT140 (Olympus). The EG38UT and the GF-UCT140, which are used with working channels of 3.8 and 3.7 mm, respectively, both allow placement of a 10-French stent. On the other hand, the FG38X has a working channel of 3.2 mm, which only permits placement of an 8.5-French stent. These instruments are coupled with an ultrasound processor such as the Aloka (Tokyo, Japan) or the EUB6000 from Hitachi (Tokyo, Japan).
●
●
Devices A 19-gauge EUS-FNA needle (Echotip, Wilson-Cook; Vizeon, CONMED) is required to pass a 0.035-inch guide wire (X-wire, Conmed Industries) into the abscess cavity. A needle-knife (Zimmon needle knife, Wilson-Cook) catheter is required to puncture the wall of the abscess to facilitate stent or drain placement. Alternatively, in patients who are at high risk for bleeding, a standard 4.5/5-French ERCP cannula and a 10-French ERCP inner guiding catheter (WilsonCook) can be passed over the guide wire, in succession, to gradually “burrow” the wall of the abscess cavity to achieve the same effect. Biliary balloon dilator (6/8 mm) or a throughthe-scope balloon (Eliminator, Multi-stage balloon dilator, CONMED; Eclipse Dilation Balloon, Wilson-Cook) is needed to further dilate the tract between the abscess cavity and rectum. A single pigtail plastic stent (8.5- or 10-French) or drain (Flexima, Boston Scientific) is required to facilitate drainage of the abscess cavity.
●
using Doppler, under EUS-guidance, a large 19-gauge needle is used to puncture the abscess cavity to gain access to the fluid collection (Fig. 3). Normal saline is used to flush the abscess cavity using a 10-mL syringe and re-aspirated to clean out the cavity of as much pus as possible. A sample of the aspirate should be sent for gram staining and culture. A 0.035-inch guide wire is then passed via the 19-gauge needle and coiled into the abscess cavity. The puncture site of the abscess cavity is then further enlarged by introducing a needle-knife catheter through the working channel of the echoendoscope and puncturing the abscess under EUS-guidance. Alternatively, in patients who are at high risk for bleeding, a 4.5/5French ERCP cannula is passed over the guide wire to dilate the wall of the abscess cavity. This is then further dilated by passing a 10-French ERCP inner guiding catheter over the guide wire. The tract is further dilated using a 6/8-mm over the wire balloon and/or by using through-the-scope balloons (6-14 mm) (Fig. 4A and B, and Fig. 5). The presence of a large opening will facilitate better drainage of the abscess and provide easy access for future interventions. This is most suitable for patients undergoing drain placement. However, dilation beyond 6 mm is not required if the intention is to only place a stent. An 8.5- or 10-French single pigtail stent is then deployed over the guide wire into the abscess to establish complete drainage. Although straight stents may be placed, there is a theoretical risk for migration into the abscess cavity. In patients with large pelvic abscesses and those in whom a quick resolution is desired, a 10-French single pigtail drain can be placed alone or in combination with a stent (Fig. 6). The drain is flushed with 50 mL of normal saline, every 8 hours, until the abscess is completely evacuated. After verifying resolution of the abscess on follow-up CT (Fig. 7), the drain and/or stent can be removed.
Procedural Technique EUS-guided drainage of pelvic abscess is comprised of the following steps: ● ●
By performing a rectal EUS examination, the pelvic abscess is first located (Figs. 1 and 2). After ensuring the absence of intervening vasculature
Figure 3 Passage of a 19-gauge needle into the pelvic abscess under EUS-guidance to facilitate drainage.
EUS-guided drainage of pelvic abscess
53
Figure 4 (A, B) Dilation of the tract by using an 8-mm biliary balloon dilator and then to 14 mm using a through-thescope balloon dilator.
Outcomes In a study of 12 patients with deep pelvic abscesses in whom EUS-guided trans-rectal stent (8.5/10-French) placement was attempted, Giovanninni and coworkers reported a technical success rate of 75% with resolution of abscess in 8 of 12 patients.5 In 3 patients, stenting was not possible due to the distance between the abscess and the rectal wall (⬎20 mm). The mean duration of stenting was 4.3 months. With the exception of 2 patients (largest abscess measured 85 ⫻ 83 mm), others had a pelvic abscess that was smaller than 60
Figure 5 Drainage of pus into the rectum postdilation.
mm. The outcome was unsuccessful in the patient with largest abscess, and he eventually required surgical drainage. No complications were encountered in this study (Table 1). As part of an ongoing prospective study, we have performed EUS-guided drainage of pelvic abscesses in four patients that were not amenable for drainage by the percutaneous route. The mean size of the abscess in these four patients was 68 ⫻ 72 mm. All patients had successful placement of a 10-French drainage catheter into the abscess cavity under EUS-guidance. The abscesses resolved spontaneously within
Figure 6 Fluoroscopic view revealing the presence of a pigtail drain into the pelvic abscess cavity.
S. Varadarajulu
54
Which Is the Best Technique to Drain Abscesses: Stent versus Drainage Catheter Placement? Experience with EUS-guided drainage of pelvic abscesses is limited. There are no studies comparing both techniques. However, due to its small caliber, trans-rectal stents can potentially clog easily, particularly by fecal matter, and when left long-term can cause peri-rectal pain or migrate spontaneously. Placing a drainage catheter enables continued access to the abscess cavity for flushing and drainage of the infected fluid collection. Also, the chance of infecting a sterile abscess is more remote with trans-rectal drain placement than with stenting. Moreover, the drain can be removed in a shorter period of time as continued therapy will potentially resolve the abscess faster. Figure 7 Repeat CT of the pelvis at day 6, showing marked reduction in size of the abscess cavity.
a mean duration of 6 days, and there was no recurrence at 3 months follow up. Although one patient died of worsening heart failure, no procedure-related complications were encountered.
Which Is the Best Technique to Dilate the Wall of the Abscess Cavity: NeedleKnife versus “Burrowing” with Catheters? In the absence of comparative data, this question is difficult to address. Perforation has been reported as a complication during EUS-guided drainage of pancreatic pseudocysts using the needle-knife technique. It can be sometimes challenging to control the direction of the cut when using needle-knife catheters, leading to inadvertent perforation. Although this could be minimized by using an over-the-wire needle knife, the needle when deployed often points in a tangential angle due to its thin caliber leading to an undesirable incision. We routinely dilate the wall of the pancreatic pseudocyst, after gaining access with a 19-gauge needle and passing a 0.035inch guide wire, using a 4.5/5-French ERCP catheter and then using a 10-French ERCP inner guiding catheter. This facilitates easy passage of 6/8-mm biliary balloon dilators and through-the-scope balloons for further dilation of the pseudocyst wall. We have experienced no complications with this technique while managing patients with pancreatic pseudocysts and have had excellent outcomes with pelvic abscesses as well. The decision to undertake either technique should be based on expertise of the endoscopist and availability of resources.
Technical Limitations Drainage of pelvic abscess cannot be undertaken when the wall of the abscess cavity is ⬎20 mm from the EUS transducer. Also, the presence of multiple cavities in an abscess precludes successful drainage. It is important to carry out a helical CT scan before embarking on this procedure because poorly defined or multilocular fluid collections are not suitable for this nonsurgical method of drainage. EUS-guided pelvic abscess drainage must be performed only in patients with a unilocular cavity.
Conclusion EUS-guided drainage can be an effective treatment modality for management of patients with abscesses or fluid collections in the pelvis that are not amenable to conventional therapy. Comparative studies with larger numbers of patients will help identify cases that benefit the most from this technique.
References 1. Hovsepian DM: Transrectal and transvaginal abscess drainage. J Vasc Interv Radiol 4:501-515, 1997 2. Brusciano L, Maffettone V, Napolitano V, et al: Management of colorectal emergencies: percutaneous abscess drainage. Ann Ital Chir 75:593-597, 2004 3. O’Neill MJ, Rafferty EA, Lee SI, et al: Transvaginal interventional procedures: aspiration, biopsy, and catheter drainage. Radiographics 3:657672, 2001 4. Nelson AL, Sinow RM, Oliak D: Transrectal ultrasonographically guided drainage of gynecologic pelvic abscesses. Am J Obstet Gynecol 6:13821388, 2000 5. Giovanninni M, Bories E, Moutardier V, et al: Drainage of deep pelvic abscesses using therapeutic echo endoscopy. Endoscopy 35:511-514, 2003 6. Varadarajulu S, Drelichman ER. EUS-guided drainage of pelvic abscess. Gastrointest Endosc (In press)
Table 1 EUS-Guided Drainage of Pelvic Abscess Author
No. of Patients
Mean Size (mm)
Drainage mode
Technical Success (%)
Giovannini Varadarajulu6
12 4
48.9 ⴛ 43.4 68 ⴛ 72
Stenting Drainage catheter
75 100
5