Percutaneous treatment of intrabdominal abscess: urokinase versus saline serum in 100 cases using two surgical scoring systems in a randomized trial

Dispelling the Myths of Percutaneous Catheter Drainage of Infected Abdominal Collections

When consulted for percutaneous catheter drainage (PCD) of abdominopelvic collections, interventional radiologists (IRs) should consider the appropriateness of this technique in the context of other options such as conservative, endoscopic, or surgical management. Whenever possible, published data should be considered prior to performing percutaneous drainage, especially as regards controversial scenarios such as the use of fibrinolytic therapy, the primary placement of large-bore drainage catheters, the drainage of cystic tumors, the drainage of splenic abscesses, and the treatment of collections lacking an in-line drainage window. This article examines past and present published data on PCD to dispel some common myths and guide IRs toward the best applications of PCD.

Safety and Feasibility of Photodynamic Therapy for Percutaneous Image-guided Abdominopelvic Abscess Drainage: Phase 1 Trial

Background Standard-of-care abscess management includes image-guided percutaneous drainage and antibiotics; however, cure rates vary, and concern for antibiotic-resistant bacteria is growing. Photodynamic therapy (PDT), which uses light-activated dyes to generate cytotoxic reactive oxygen species, could complement the standard of care by sterilizing the abscess at the time of drainage. Purpose To evaluate safety and feasibility of PDT with methylene blue (hereafter, MB-PDT) at the time of percutaneous abscess drainage. Materials and Methods This prospective, open-label, dose-escalation, first-in-humans, registered phase 1 clinical study of MB-PDT included participants who underwent percutaneous abdominal or pelvic abscess drainage with CT or US guidance from January 2015 to March 2020 and September 2022 to September 2023. Following drainage, MB-PDT was performed with laser illumination at a fluence rate of 20 mW/cm2, with fluence groups of 6, 12, 18, 24, 30, and 36 J/cm2 (n = 3 each). The primary outcome was safety, indicated by absence of fat embolism, MB escape, abscess wall damage, and need for surgery to remove optical fibers. Preliminary efficacy end points included the time to drainage catheter removal, drainage catheter output volume, and clinical symptom and fever duration. Relationships between fluence and outcomes were analyzed with Spearman correlation and linear regression analyses, and ordinary one-way analysis of variance was used for group comparisons. Results MB-PDT was safe and feasible in all 18 participants (mean age, 60.1 years ± 18.3 [SD]; 10 female), with no negative safety outcomes observed for any participant. No study-related adverse events were encountered, and the procedure did not increase reported pain (P = .1). Clinical symptom and fever duration was shorter in participants receiving higher fluences (30 and 36 J/cm2 vs 6 J/cm2) (P = .03). The presence of antibiotic-resistant bacteria was not predictive of clinical symptom and fever duration (β = 0.13, P = .37). Conclusion MB-PDT was a safe and feasible adjunct to image-guided percutaneous abscess drainage. Clinical measures indicated a dose-dependent response to PDT. ClinicalTrials.gov registration no.: NCT02240498 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Johnston and Goldberg in this issue.

Photodynamic therapy is a safe and feasible adjunct to percutaneous drainage of deep tissue abscesses: Results of a first in humans Phase 1 clinical trial

Background

Standard of care for abscess management includes image-guided percutaneous drainage and antibiotics. However, cure rates vary between patients and there is growing concern for antibiotic-resistant bacteria. Photodynamic therapy (PDT), which utilizes light-activated dyes to generate cytotoxic reactive species, could complement the standard of care by sterilizing the abscess at time of drainage.

Purpose

The goal of this study was to perform a first in humans Phase 1 clinical study evaluating safety and feasibility of PDT with methylene blue (MB) at the time of percutaneous abscess drainage. This was accomplished through an open-label dose escalation study, with duration of light delivery escalated from 5-30 minutes.

Materials and Methods

We performed MB-PDT in 18 subjects undergoing percutaneous abscess drainage. Following standard of care drainage, 1 mg/mL MB was delivered for 10 minutes. MB was aspirated, and 1% lipid emulsion infused to homogenize light dose at the cavity wall. An optical fiber was advanced to the approximate center of the abscess for 665 nm laser illumination at 20 mW/cm 2 .

Results

MB-PDT at the time of abscess drainage was safe and feasible in all cases, with no evidence of fat embolism due to lipid emulsion or adverse reaction to MB observed. No study-related adverse or serious adverse events were encountered, and the procedure was well tolerated by all subjects. While the study was not designed or powered to determine efficacy, time to resolution of clinical symptoms was significantly decreased in subjects receiving higher fluences (p=0.028). Additionally, drainage catheter output post-procedure was decreased in subjects receiving higher fluences (ρ=-0.18), although this difference was not significant (p=0.43).

Conclusion

MB-PDT is a safe and feasible adjunct to image-guided percutaneous abscess drainage. Clinical measures indicate a dose-dependent response to PDT, motivating future Phase 2 studies evaluating the efficacy of MB-PDT in this patient population.

ACR Appropriateness Criteria® Radiologic Management of Infected Fluid Collections

Infected fluid collections are common and occur in a variety of clinical scenarios throughout the body. Minimally invasive image-guided management strategies for infected fluid collections are often preferred over more invasive options, given their low rate of complications and high rates of success. However, specific clinical scenarios, anatomic considerations, and prior or ongoing treatments must be considered when determining the optimal management strategy. As such, several common scenarios relating to infected fluid collections were developed using evidence-based guidelines for management. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Use of Tissue Plasminogen Activator in Abdominal Abscesses in Children-A Single-Center Randomized Control Trial

PURPOSE

To establish the efficacy of once-per-day intracavitary tissue plasminogen activator (tPA) in the treatment of pediatric intra-abdominal abscesses.

METHODS

A single-center prospective, double-blinded, randomized controlled trial of the use of intracavitary tPA in abdominal abscesses in children. Patients were randomized to either tPA-treatment or saline-treatment groups. Primary outcome was drainage catheter dwell (hours). Secondary outcomes were length of hospital stay, times to discharge, clinical and sonographic resolution, and adverse events (AEs).

RESULTS

Twenty-eight children were randomized to either group (n = 14 each). Demographics between groups were not significantly different (age P = .28; weight P = .40; gender P = .44). There were significantly more abscesses in the tPA-treated group (P = .03). Abscesses were secondary to perforated appendicitis (n = 25) or postappendectomy (n = 3). Thirty-four abscesses were drained, 4 aspirated, 3 neither drained/aspirated. There was no significant difference in number of drains (P = .14), drain size (P = .19), primary outcome (P = .077), or secondary outcomes found. No procedural or intervention drug-related AEs occurred. No patient in the saline-treated group required to be switched/treated with tPA.

CONCLUSION

No significant difference in the length of catheter dwell time, procedure time to discharge, or time to resolution was found. Intracavitary tPA was not associated with morbidity or mortality. The results neither support nor negate routine use of tPA in the drainage of intra-abdominal abscess in children. It is possible that a multicentre study with a larger number of patients may answer this question more definitively.

Use of the Recombinant Tissue Plasminogen Activator in the Management of Complex Infected Intraperitoneal Fluid Collection

Intra-abdominal infections and infected fluid collections are the result of local infection typically involving the gastrointestinal or genitourinary tract. These infections are usually polymicrobial. The management of such patients should include source control and appropriate antimicrobial therapy. Source control is essential and can be achieved either surgically or by percutaneous drainage of intra-abdominal fluid collection. Interventional radiology drainage of intra-abdominal fluid collections may be especially important in patients with high surgical risk or in patients who refuse surgery. Below, we present a case of successful use of recombinant intraperitoneal tissue plasminogen activator use in a patient with a complex polymicrobial fluid collection.

Minimally invasive treatment of complex collections: safety and efficacy of recombinant tissue plasminogen activator as an adjuvant to percutaneous drainage

Objective

To analyze the efficacy of recombinant tissue plasminogen activator (r-TPA) injection in the evolution of percutaneous drainage of thick collections.

Materials and Methods

This was a single-center study involving the retrospective analysis of hospitalized patients undergoing percutaneous drainage of thick (superficial or intracavitary) fluid collections, followed by injection of a fibrinolytic agent (r-TPA) into the affected space.

Results

A total of 53 percutaneous drainage procedures, with r-TPA injection, were performed in 51 patients. Abdominal and pelvic collections were the most common, being seen in 38 (73%) of the procedures; in 35 (66%), the etiology of the collection was attributed to postoperative complications. A total of 61 catheters were used in order to drain the 53 collections. Of those 61 catheters, 52 (85%) were large (12-16 Fr) and 9 (15%) were small (4-10 Fr). The mean r-TPA dose was 5.7 mg/collection per day, and the mean time from r-TPA injection to drain removal was 7.7 days. Percutaneous drainage in combination with r-TPA injection was successful in 96% of the cases. None of the patients showed coagulation changes during the study period.

Conclusion

The use of once-daily, low-dose r-TPA for up to three consecutive days, as an adjunct to percutaneous drainage of thick collections, with or without loculation, appears to be an effective technique.

Alcoholization of pyogenichepatic abscess with absolute alcohol in Bama minipigs

Pyogenic hepatic abscess (PHA) is a rare, but potentially serious disease. At present, ultrasound-guided or computed tomography-guided percutaneous needle aspiration or catheter drainage is appropriate as a first-line treatment. However, it is difficult to aspirate or drain pus and to select the appropriate antibiotic therapy if the abscess consists of thick pus and polymicrobial confections, or its pathogenic bacterium is multidrug resistant and cryptogenic. Case studies of alcoholization provide a novel method to manage PHA. However, the efficacy and safety of this treatment should be further evaluated. In the present study, the therapeutic efficacy and complications of alcoholization for PHAs in Bama minipigs were investigated. PHAs were prospectively treated by ultrasound-guided percutaneous instillation of absolute alcohol in the abscess cavity. The criteria for considering a successful intervention were met in all minipigs subsequent to alcoholization twice within 14 days. The procedures were well tolerated in all animals, and there were no alcoholic adverse effects or procedure-associated complications. In conclusion, ultrasound-guided percutaneous alcoholization is a safe and effective procedure to manage PHA. The problems of thick pus aspiration and selection of an appropriate antibiotic observed in other treatments were resolved effectively using alcoholization. This technique may reduce the treatment period and possibly become a novel strategy for the management of PHA.

Saline vs Tissue Plasminogen Activator Irrigations after Drain Placement for Appendicitis-Associated Abscess: A Prospective Randomized Trial

BACKGROUND

Emerging data suggest instillation of tissue plasminogen activator (tPA) is safe and potentially efficacious in the treatment of intra-abdominal abscess. To date, prospective comparative data are lacking in children. Therefore, we conducted a randomized trial comparing abscess irrigation with tPA and irrigation with saline alone.

STUDY DESIGN

After IRB approval, children with an abscess secondary to perforated appendicitis who had a percutaneous drain placed for treatment were randomized to twice-daily instillation of 13 mL 10% tPA or 13 mL normal saline. All patients were treated with once-daily dosing of ceftriaxone and metronidazole throughout their course. The primary end point variable was duration of hospitalization after drain placement. Using a power of 0.8 and an α of 0.05, a sample size of 62 patients was calculated.

RESULTS

Sixty-two patients were enrolled between January 2009 and February 2013. There were no differences in demographics, abscess size, abscess number, admission WBC, or duration of symptoms. Duration of hospitalization after drainage was considerably longer with the use of tPA. There was no difference in total duration of hospitalization, days of drainage, or days of antibiotics. However, medication charges were higher with tPA.

CONCLUSIONS

There are no advantages to routine tPA flushes in the treatment of abdominal abscess secondary to perforated appendicitis in children.

Radiologic drainage of post-operative collections and abscesses

Since the initial studies published in the eighties, percutaneous radiologic drainage, is considered the first-line treatment of infected post-operative collections and is successful in over 80% of patients. Mortality due to undrained abscesses is estimated between 45 and 100%. Radiology-guided percutaneous drainage can be performed either with curative intent or to improve patient status prior to re-operation under better conditions. Cross-sectional imaging, using either ultrasound or computed tomography (CT), has changed the management of post-operative complications. Percutaneous drainage is most often performed by interventional radiologists and imaging is essential for road-mapping and guiding the puncture and drainage of intra-abdominal collections. Indeed, such imaging allows both identification of adjacent anatomical structures and determination of the best tract and the safest route. Cooperation between the surgeon and the interventional radiologist is essential to optimize the management and to avoid, if possible, surgery, which is so often difficult in this setting.

The role of tissue plasminogen activator in the management of complex intra-abdominal abscesses in children

OBJECTIVE

The objective of this study is to assess the safety of fibrinolytic therapy using tissue plasminogen activator (tPA) in children with complex intra-abdominal abscesses.

SUMMARY BACKGROUND DATA

Intra-abdominal abscesses are common in children. Antibiotics and percutaneous drainage are the mainstays of treatment, but drainage may be less effective when the fluid is thick or septated. Fibrinolytic therapy using tPA is effective in a rat model of intra-abdominal abscesses, has recently been reported for the treatment of intra-abdominal abscesses in adults, and is commonly used in the treatment of empyema in children.

METHODS

This is a retrospective review of all patients over a 10-year period who had intra-abdominal collections managed with tPA abscess drainage.

RESULTS

Sixty-four children had a total of 66 drains placed and 92 doses of tPA. Appendicitis was the cause of the abscesses in 52 of 64 children. Mean length of stay pre-tPA was 11.7 ± 7.63 days, mean time from drain insertion to tPA was 4.3 ± 3.78 days, and mean time from tPA to discharge was 8.6 ± 8.85 days. Thirty patients underwent an operation before tPA administration. No patients experienced bleeding complications, anastomotic or appendiceal stump leak, or wound dehiscence after the administration of tPA, and no patients had abnormalities in coagulation studies related to tPA administration. One child died of sepsis.

CONCLUSIONS

Tissue plasminogen activator is safe for the management of thick or septated intra-abdominal abscesses in children. A prospective controlled study will be needed to evaluate the efficacy of this technique.

Treatment of deep intramuscular and musculoskeletal abscess: experience with 99 CT-guided percutaneous catheter drainage procedures

OBJECTIVE

The purpose of this article is to describe our experience draining deep muscular and musculoskeletal abscess collections with CT guidance, emphasizing clinicopathologic factors associated with drain failure, and to further analyze patient outcomes according to whether the process involves muscle alone or also involves adjacent bone or joint (skeletal involvement).

MATERIALS AND METHODS

The details of percutaneous catheter drainage were retrospectively recorded for all drainages performed over a 9-year period. The technical and clinical successes of percutaneous catheter drainage were determined. Multifactor logistic regression analysis was used to identify predictors of drain failure (malignancy, age, chemotherapy, surgery, infection, complexity, size, days in situ, and skeletal involvement). These parameters were assessed in all patients, those with muscle involvement alone and those with musculoskeletal collections.

RESULTS

Eighty-nine of 94 patients underwent one percutaneous drainage procedure and 5 of 94 patients underwent two drainages for a total of 99 drainages in 94 patients (one drainage [n = 89] and two drainages [n = 5]). There were 62 men and 32 women with a mean age of 58.5 years (age range [±SD], 22.3-88.0 ± 16 years). The abscess diameters ranged from 1.8 to 13 cm (mean, 5.3 ± 2.5 cm), volume aspirated ranged from 0 to 200 mL (mean, 45 ± 44 mL), and mean duration of drainage was 16.2 days (range, 2-110 ± 18.7 days). The iliopsoas muscle was the most common site of drainage, accounting for 87.8% of the total. Catheter insertion was possible in all patients, with the muscular component successfully drained in 82% (81/99) overall: 85% (46/54) of those with muscle involvement alone and 77% (35/45) of those with musculoskeletal collections. Catheter drainage and antibiotic administration resulted in 65.6% (65/99) not requiring any surgical intervention and resolution of abnormal white cell count or fevers in 98.8% (79/80) of those with abnormal parameters before treatment. Skeletal infection was associated with increased risk of drainage failure (p = 0.0001).

CONCLUSION

Percutaneous imaging-guided musculoskeletal drainage is clinically useful, safe, and effective for draining complex musculoskeletal collections. It is highly effective for draining collections involving muscle alone; however, skeletal infection is associated with a higher risk of drain failure.