Non-traumatic abdominal emergencies: imaging and intervention in sepsis

Cross-sectional imaging, in particular CT, has become the main method of detecting abdominal collections. Indium-labelled white-cell scintigraphy and gallium scintigraphy are reserved for patients in whom there is a high clinical suspicion of abdominal sepsis but CT has not revealed a source of sepsis. Scintigraphy is also used in patients with suspected vascular graft infections or suspected infected hip prostheses. Percutaneous abscess drainage (PAD) has revolutionised the treatment of abdominal abscesses over the past 20 years, with repeat laparotomy for postoperative abscesses becoming a rare event. Ultrasound or CT can be used to guide PAD. Choosing an access route that does not cross intervening organs is of crucial importance to the safe performance of PAD. The Trocar or Seldinger techniques can be used with equal success. The cavity should be aspirated until dry and irrigated with saline. Repeat imaging after drainage is helpful to detect any undrained locules. PAD endpoints include patient defervescence, reduction in white blood cell count and catheter drainage of less than 10 ml per day. Details regarding PAD in specific abdominal regions are discussed. Success rates for PAD are high (close to 90%) in most abdominal organs. Slightly lower success rates are seen with PAD of pancreatic abscesses and abscesses associated with fistulas (60-85% success rates). Complication rates lie between 0% and 10%. Complications can be minimised by ensuring that the patient has broad spectrum antibiotic coverage before drainage, by carefully planning the access route and by ensuring diligent post-procedure care by radiology staff.     

Interventional MR imaging: percutaneous abdominal and skeletal biopsies and drainages of the abdomen

Since the introduction of open magnets and short-bore closed magnets, and the availability of fast imaging sequences, MR imaging has become a tool for guidance and control of percutaneous nonvascular and vascular procedures. In general, percutaneous biopsies or drainages require no specific hardware or software modifications. For lesion localization and control of the needle track, simple fast imaging sequences such as fast T1-weighted gradient-echo techniques or fast single-shot T2-weighted spin-echo sequences are sufficient and can be applied depending on the best tissue-to-lesion contrast. Typical scan times range from 1 to 3 s. Different types of biopsy needles are commercially available, allowing sampling of sufficient amounts of tissue. For drainage procedures non-ferromagnetic materials, such as nitinol wires, should be preferred to minimize image distortion by metallic artifacts. Indications for percutaneous biopsies include subdiaphragmatic liver lesions, lesions poorly visible on ultrasound or contrast-enhanced computed tomography, and lesions of the bone marrow characterized by an unspecific bone marrow edema. For percutaneous drainages, subdiaphragmatic lesions appear to be a good indication. With some experience the procedure time is not longer than that under CT or US guidance.     

Percutaneous cystogastrostomy with a new catheter for drainage of pancreatic pseudocysts and fluid collections

We describe a new catheter for the initial percutaneous drainage of large symptomatic pancreatic fluid collections and abscesses using a transgastric approach to allow fluid drainage into the gastric lumen. A doublemushroom stent is placed secondarily for long-term internal drainage to the stomach, avoiding the need for an extended period of external catherter drainage. This technique, termed percutaneous cystogastrostomy (PCG), has been used in 19 consecutive patients with one recurrent symptomatic pseudocyst in the follow-up period of 9–43 months. There was one death within 30 days of PCG and 1 patients proceeded to surgical necrosectomy. After evidence of resolution of the pseudocysts, the internal stent was retrieved in 17 patients by endoscopic snare.     

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

The purpose of this study was to assess whether regular instillation of urokinase during abscess drainage leads to an improved outcome compared to saline irrigation alone. One hundred patients referred for image-guided abdominal abscess drainage were randomized between thrice daily urokinase instillation or saline irrigation alone. At the end of the study, patient medical records were reviewed to determine drainage, study group, Altona (PIA II) and Mannheim (MPI) scoring, duration of drainage, procedure-related complications, hospital stay duration, and clinical outcome. The technical success rate of the percutaneous abscess drainage was 100%. The success or failure of abscess remission did not differ significantly between groups (success rate of 91.5% in the urokinase group vs. 88.8% in the saline group; failure rate was of 8.5 vs. 21.2%, respectively); however, days of drainage, main hospital stay, and overall costs were significantly reduced in patients treated with urokinase compared to the control group (P < 0.05). No adverse effects from urokinase were observed. Surgical scores were a useful homogeneity factor, and MPI showed a good correlation with prognosis, while PIA results did not have a significant correlation. For drainage of complex abscesses (loculations, hemorrhage, viscous material), fibrinolytics safely accelerate drainage and recovery, reducing the length of the hospital stay and, therefore, the total cost.     

CT引导下肝脓肿穿刺置管引流术的探讨

目的 探讨CT引导下肝脓肿穿刺引流术的方法和疗效.方法 本组20例肝脓肿患者,均经临床、生化和影像学(CT)检查确诊为肝脓肿,行CT引导下定位穿刺抽吸并置管引流.脓肿位于肝左叶6例,肝右叶9例,肝2叶5例.结果 14例为单个脓肿,6例为多发脓肿,单个脓肿经1次抽吸后脓肿完全消失9例,1例经2次抽吸基本消失,多发或多房脓肿穿刺先抽较大脓肿,后抽较小脓肿,或分次抽吸,20例均放置引流管并冲洗,平均引流置管时间为19.2 d,所有患者至随访截止日未见复发.结论 CT引导下穿刺抽吸引流足治疗肝脓肿的非常有效的方法.     

Technical note: Use of a double-needle technique for safer entry into an abdominal abscess

Where a potentially hazardous approach for drainage of an intra-abdominal abscess or fluid collection is unavoidable, the double-needle puncture technique described here can prevent inadvertent penetration of bowel.     

Colouterine fistula and pyometrium treated with percutaneous drainage: A case report

Percutaneous drainage of intraabdominal abscesses has become a routine procedure for preoperative confirmation of diagnosis and patient stabilization, and often provides definitive therapy. Diverticulitis is a frequent cause of pericolonic abscess but rarely results in colouterine fistula and pyometrium. We describe the first reported percutaneous drainage of such a case of pyometrium.     

超声引导经皮肝穿刺引流术治疗细菌性肝脓肿

 目的 评价超声引导经皮肝穿刺引流术在细菌性肝脓肿治疗中的临床应用价值.方法 对35例超声引导下经皮肝穿刺引流(穿刺组)和同期36例手术切开引流(手术组)治疗细菌性肝脓肿的疗效进行对照分析.结果 穿刺组治愈率(97.1 %)与手术组治愈率(94.4%)差异无统计学意义(P＞0.05),而穿刺组在住院天数、术后血象恢复正常时间、术后体温恢复正常时间、脓腔消失时间、治疗费用方面明显优于手术组(P＜0.01),术后并发症在穿刺组明显少于手术组(P＜0.05). 结论与传统手术切开引流术相比,经皮肝穿刺引流术具有安全、微创、简便、康复快和经济等优点,可以作为细菌性肝脓肿首选治疗方法.     

CT-guided percutaneous drainage of intra-abdominal abscesses: APACHE III score stratification of 1-year results. Acute Physiology,Age, Chronic Health Evaluation

Our objective was to evaluate the clinical success rates of percutaneously drained intra-abdominal abscesses using a risk stratification score for severely ill patients (APACHE III; Acute Physiology, Age, Chronic Health Evaluation). In 75 patients CT-guided percutaneous abscess drainage was performed to treat intra-abdominal abscesses. The clinical success rate based on a 1-year follow-up was correlated with abscess etiology, size, and structure, as well as with the initial APACHE III score. Clinical success, i.e., the complete removal of the abscess without surgical treatment, was observed in 62 of 75 patients (83%). Abscess size (<200 cm³) and abscesses with a simple structure correlated with higher clinical success rates. Patients presenting with APACHE III scores below 30 were treated by percutaneous abscess drainages (PAD) alone significantly more often than patients presenting with higher APACHE scores. The percutaneous drainage of intra-abdominal abscesses shows good long-term results as long as abscesses are singular, small (<200 cm³), and located in well accessible regions in combination with low APACHE scores (<30). Electronic Publication     

MR-guided radiofrequency ablation of hepatic malignancies at 1.5 T: initial results

Purpose

To assess the feasibility of magnetic resonance (MR)‐guided radiofrequency ablation (RFA) of hepatic malignancies using a high‐field MR scanner.

Materials and Methods

A total of 10 patients with 14 primary (N = 1) or secondary (N = 13) hepatic malignancies underwent MR‐guided RFA using a closed‐bore 1.5 T MR scanner. Lesion diameters ranged from 2.0 cm to 4.7 cm. RFA was performed using a 200‐W generator in combination with a 3.5‐cm LeVeen electrode applying a standardized energy protocol.

Results

RFA was technically feasible in all patients. Necrosis diameter ranged from 2.5 cm to 6.8 cm. The mean follow‐up period is 12.2 ( 1 - 18 ) months. In nine out of 10 patients, local tumor control was achieved. For this purpose, a second CT‐guided RFA was required in two patients. In four patients, multifocal hepatic tumor progression occurred, with the treated lesion remaining tumor‐free in three of these patients. Two patients showed extrahepatic tumor progression. Four patients remained tumor‐free. No major complications occurred.

Conclusion

MR‐guided RFA of hepatic malignancies in a closed‐bore high‐field MR scanner is technically feasible and safe. It can be advantageous in locations considered unfavorable for CT‐guided puncture or in patients in which iodinated contrast material is contraindicated. J. Magn. Reson. Imaging 2004;19:342–348. © 2004 Wiley‐Liss, Inc.

     

MR-guided biopsies with a newly designed cordless coil in an open low-field system: Initial findings

The purpose of this study was to examine the feasibility and safety of MR-guided biopsies with a newly designed cordless coil in an open low-field magnetic resonance (MR) system. Eleven patients were biopsied using a low-field system (0.2 T, Magnetom Concerto, Siemens) by using the new cordless coil (Siemens). The biopsies were performed in different organ systems [liver (n=7), abdomen (n=1), shoulder (n=1), pelvis (n=1) and hip (n=1)]. The procedures were guided using T1-weighted FLASH (fast low-angle shot) sequences. The lesions were biopsied using the coaxial technique through a 15-gauge puncture needle with a 16-gauge biopsy handy. Coil handling, image quality and complications were evaluated. Imaging quality and visualization of the lesions were optimal up to a penetration depth of 9 cm. In all cases the biopsy procedures were successfully performed with MR guidance without any complications. Pathological findings revealed seven cases of malignant tissue and four cases of non-malignant tissue. The use of the cordless coil allows improved patient access during the biopsy and an improved handling of the coil system. MR-guided biopsy using the novel cordless coil system can be performed safely and precisely with easy handling of the coil. This coil concept, however, is restricted to special indications.     

Percutaneous drainage of postappendectomy abscesses complicated by enteric communication

Four patients with postappendectomy abscesses complicated by enteric fistulae were treated by percutaneous drainage. Sinograms, obtained at the time of the initial drainage, demonstrated communication to the cecum in 3 patients and to the small bowel in 1 patient. Complete cure was attained in 3 patients by percutaneous drainage. In the fourth patient, surgery was performed after 7 days of catheter drainage. Percutaneous drainage of abscesses with enteric communication requires a modified technique, which includes longer-term drainage than for simple noncommunicating abscesses.     

MR-guided transgluteal biopsies with an open low-field system in patients with clinically suspected prostate cancer: technique and preliminary results

The purpose of this study was to examine the feasibility and safety of MR-guided biopsies with a transgluteal approach in patients with uncertain or suspicious prostate lesions. Twenty-five patients with uncertain or suspicious focal prostate lesions detected by high-field MR imaging of the prostate gland using endorectal coil imaging were biopsied with a transgluteal approach in a low-field MRI system (0.2 T, Concerto, Siemens). The procedures were guided using T1-weighted FLASH sequences. The prostate gland was biopsied repeatedly with a coaxial technique through a 15-gauge pencil tip with a 16-gauge biopsy handy (median 3.8 samples per patient). Complications and biopsy findings were documented retrospectively. Using T1-weighted sequences biopsy procedures were performed successfully with MR guidance in all cases without any side effects or complications. The median intervention time was 11.3 min. Pathological findings revealed ten cases of hyperplasia or atrophy, three cases of prostatitis, ten cases of carcinoma and two cases of normal tissue. The clinical follow-up showed that in two patients prostate cancer was missed at MR-guided biopsy. Transgluteal MR-guided biopsy of the prostate gland is a safe and promising approach for histological clarification of uncertain or suspicious lesions.     

MR-guided percutaneous angioplasty: Assessment of tracking safety, catheter handling and functionality

Purpose: Magnetic resonance (MR)-guided percutaneous vascular interventions have evolved to a practical possibility with the advent of open-configuration MR systems and real-time tracking techniques. The purpose of this study was to assess an MR-tracking percutaneous transluminal angioplasty (PTA) catheter with regard to its safety profile and functionality. Methods: Real-time, biplanar tracking of the PTA catheter was made possible by incorporating a small radiofrequency (RF) coil in the catheter tip and connecting it to a coaxial cable embedded in the catheter wall. To evaluate potentially hazardous thermal effects due to the incorporation of the coil, temperature measurements were performed within and around the coil under various scanning and tracking conditions at 1.5 Tesla (T). Catheter force transmission and balloon-burst pressure of the MR-tracking PTA catheter were compared with those of a standard PTA catheter. The dilatative capability of the angioplasty balloon was assessed in vitro as well as in vivo, in an isolated femoral artery segment in a swine. Results: The degree of heating at the RF coil was directly proportional to the power of the RF pulses. Heating was negligible with MR tracking, conventional spin-echo and low-flip gradient-echo sequences. Sequences with higher duty cycles, such as fast spin echo, produced harmful heating effects. Force transmission of the MR-tracking PTA catheter was slightly inferior to that of the standard PTA catheter, while balloon-burst pressures were similar to those of conventional catheters. The MR-tracking PTA catheter functioned well both in vitro and in vivo. Conclusion: The in vivo use of an MR-tracking PTA catheter is safe under most scanning conditions.     

Late complication following percutaneous cholecystostomy: retained abdominal wall gallstone

A case of recurrent abdominal wall abscess following percutaneous cholecystostomy (PC) is presented. Transperitoneal PC was performed in an 82-year-old female with calculous cholecystitis. Symptoms resolved and the catheter was removed 29 days later. The patient came back 5 months later with a superficial abscess that was drained and 8 months post PC with a fistula discharging clear fluid. Ultrasonography revealed the tract adjacent to an area of inflammation containing a calculus, whereas CT failed to depict the stone. Subsequent surgery confirmed US findings. To our knowledge, this is the first report of a dislodged bile stone following percutaneous cholecystostomy. Received: 27 August 1999; Revised: 7 December 1999; Accepted: 9 December 1999     

改良式经皮肝穿刺胆道内外引流术治疗高位胆道恶性梗阻效果的初步临床观察

目的 探讨改良式经皮肝穿刺胆道内外引流术(PTBIED)的可行性及临床效果.方法 3年之间连续就诊的,经影像检查(部分经病理检查)证实为恶性梗阻性黄疸的患者纳入研究.其中,胆道梗阻部位在肝门部至胆总管近段,残留的胆总管长度＞3 cm,血清总胆红素(TBIL)≥70μmol/L的患者,纳入试验组,行改良式PTBIED;符合前述条件但不愿行改良式PTBIED的患者和低位恶性胆道梗阻的患者纳入对照组,按常规行传统式PTBIED.试验组患者根据术中造影,对胆道外引流管增加侧孔改造,将改造后的引流管头端置入残留的肝总管或胆总管,同时将增加的侧孔置于梗阻近侧扩张的胆管内.记录手术前后患者的临床症状、肝功能、血常规及并发症情况.术后随访至患者死亡.本研究中,2组患者计量资料的比较采用t检验,计数资料比较采用x2检验,生存时间的比较采用生存分析.结果 46例患者被纳入本研究.其中21例行改良式PTBIED,25例行传统PTBIED,2组患者均手术成功,无手术相关死亡.2组患者在皮肤瘙痒、纳差、腹胀、腹痛等临床症状改善方面相似,术后胆汁日平均引流量[试验组(521±136) ml/d,对照组(606±159) ml/d(t=1.930,P＞0.05)]、血清TBIL下降水平[试验组(87±51)mol/L,对照组(105±66) μmol/L(t=1.061,P＞0.05)]、中位生存期[试验组7.7个月,对照组6.9个月(x2=0.610,P＞0.05)]比较差异均无统计学意义.术后对照组白细胞计数为(10.9±5.2)×109/L,较术前的(7.8±2.9)×109/L明显增高,差异有统计学意义(t =3.606,P＜0.05);试验组术前为(8.2±3.4)×109/L,较术后的(7.4±2.6)×109/L明显降低(t =2.649,P＜0.05).术后试验组患者未出现十二指肠液反流现象,1例发生胆道感染;对照组11例患者发生十二指肠液反流,其中8例发生胆道感染.术后胆道感染发生率对照组明显高于试验组(x2 =5.381,P＜0.05).结论 改良式PTBIED方便、可行,相对传统PTBIED,可减少胆道感染并发症发生率.     

Non-surgical drainage of intra-abdominal and mediastinal abscesses: A report of twelve cases

Twelve patients with intra-abdominal or mediastinal abscesses were treated by percutaneous drainage. Three abscesses were subphrenic, three were adjacent to enteric leaks, two were intrahepatic, two were pancreatic pseudocysts, one was a pancreatic abscess extending to the lesser sac, and one was an infected adrenal hematoma. All 12 lesions were entered percutaneously using fluoroscopic guidance without traumatizing the adjacent normal tissue. Localization was frequently aided by computed tomography. Various catheters were positioned using basic angiographic techniques. Following drainage all patients had a favorable clinical response. Seven of the 12 patients required no surgical management. Careful radiologic follow-up and frequent changing of catheters was necessary in six of the patients. Two patients benefited from the addition of auxiliary drains. Five of the 12 patients were electively operated upon because of incomplete drainage of the abscess cavity. Causes of failure were: persistent anastomotic leak (two patients), sequestered, loculated extension of abscess cavity (two patients), or necrotic, viscous hepatic tissue requiring removal at laparotomy (one patient).     

Pyogenic liver abscess treated by percutaneous catheter drainage: MDCT measurement for treatment outcome

Objective

To analyze multidetector computed tomographic (MDCT) parameters in patients with pyogenic liver abscess (PLA), and to identify which parameters can be predicted percutaneous catheter drainage (PCD) treatment outcome.

Materials and methods

Clinical, laboratory and MDCT findings of 175 patients with PLA who had undergone PCD were retrospectively reviewed. All abscesses shown on MDCT were evaluated for size, margin, attenuation values, location, number of large (>3 cm) abscesses, presence of a cystic component, presence of gas, and the shortest length to the liver capsule. Univariate and multivariate analyses of the MDCT parameters that affect PCD treatment outcome was performed. For continuous data of MDCT parameters (abscess size and the shortest length), we used receiver-operating-characteristic (ROC) curve to determine the optimal cut-off values.

Results

PCD was failed in 32 patients and the overall failure rate was 18.28%. Multivariate analysis revealed that PCD failure was predicted by the presence of gas (odds ratio [OR], 42.67), a large abscess (OR 1.21), low minimal attenuation values (OR 1.02), wide range of attenuation values (OR 1.01), a shorter length to the liver capsule (OR 0.09) and lack of a cystic component (OR 0.09) of the PLA. ROC curve showed that the shortest length less than 0.25 cm and an abscess size greater than 7.3 cm were the optimal cut-off values predicting PCD treatment failure.

Conclusion

Among these MDCT parameters, gas formation within PLA was the most important predictor for PCD failure. Surgical intervention might be considered early in high-risk patients of PCD failure.     

Interventional MR: vascular applications

Three strategies for visualisation of MR-dedicated guidewires and catheters have been proposed, namely active tracking, the technique of locally induced field inhomogeneity and passive susceptibility-based tracking. In this article the pros and cons of these techniques are discussed, including the development of MR-dedicated guidewires and catheters, scan techniques, post-processing tools, and display facilities for MR tracking. Finally, some of the results obtained with MR tracking are discussed.     

MR-guided core biopsy with MR fluoroscopy using a short, wide-bore 1.5-Tesla scanner: feasibility and initial results

PURPOSE: To evaluate MR fluoroscopy in a short, wide-bore 1.5T MRI suitable for near real-time biopsy guidance. MATERIALS AND METHODS: A total of eight consecutive patients underwent MR-guided core biopsy in a 1.5T system with a 70 cm bore diameter. A total of five biopsies were performed in focal liver lesions, three biopsies in soft-tissue tumors. Before biopsy, three different fast MR sequences were compared for image quality (anatomical visibility, lesion visibility, and artifacts), and signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. In all cases, an MR-compatible guidance needle was positioned under MR fluoroscopy using the most suitable sequence. RESULTS: In each patient the guidance needle could be placed accurately under MR fluoroscopy without having to remove the patient from the isocenter of the magnet during needle movement. All biopsies were technically successful and appropriate specimens could be obtained. In prebiopsy imaging, a T2-weighted single shot turbo spinecho sequence (half-Fourier acquisition single-shot turbo spin-echo [HASTE]) achieved the best rating for lesion visibility and superior SNR and CNR values. CONCLUSION: Findings of this study demonstrate that MR fluoroscopy for biopsy guidance in a short, wide-bore 1.5T scanner is feasible. This scanner combines the patient access advantages of an open-bore system with the superior image quality and speed of a high-field scanner. In our series, the HASTE sequence was best suited for MR-guidance of biopsies.