Chung Dann Kan

In situ reconstruction of septic aortic pseudoaneurysm due to Salmonella or Streptococcus microbial aortitis: long-term follow-up.

OBJECTIVE This study was undertaken to illustrate the safety of in situ reconstruction of septic aortic pseudoaneurysm (SAP) secondary to microbial aortitis, with or without long-term antibiotic treatment. METHODS Data for patients with SAP (11 abdominal, 4 thoracic) operated on between 1993 and 1999 were reviewed. Computed tomography and aortography showed septic pseudoaneurysm in all patients before surgery. After diagnosis of SAP, all patients underwent aneurysm resection and extensive debridement, with in situ prosthetic grafting or patch repair angioplasty. The graft in 10 of the 11 patients with abdominal SAP was also wrapped with an omental pedicle. In vitro active parenteral antibiotic therapy was prescribed for all patients for at least 2 to 8 weeks after surgery. RESULTS All 15 patients had positive preoperative blood cultures or intraoperative tissue cultures for Salmonella spp (n = 12), viridans Streptococcus (n = 1), group G Streptococcus (n = 1), or Streptococcus pneumoniae (n = 1). There were two perioperative deaths (13.3%), one 6 days after surgery and the other 19 days after surgery, and two late deaths, at 8 and 10 months after surgery, neither of which was related to aortic repair. One patient was unavailable for follow-up. The other 10 patients have been regularly followed up with abdominal ultrasound or computed tomography (mean, 84 months; range, 47-118 months). To date, there has been no graft infection, thrombosis, false aneurysm, or subsequent aortic surgery in these 10 patients. CONCLUSION SAP due to Salmonella and streptococcal microbial aortitis can be successfully treated with resection of the aneurysm and extensive debridement, followed by in situ prosthetic graft interposition or patch repair aortoplasty. This is a safe and effective treatment that may result in complete remission of SAP. Postoperative parenteral antibiotic therapy should be continued for 2 to 8 weeks. Although usually recommended, lifelong suppressive antibiotic therapy appears to be nonessential with this approach.

The Efficacy of Aortic Stent Grafts in the Management of Mycotic Abdominal Aortic Aneurysm-Institute Case Management with Systemic Literature Comparison

BACKGROUND Conventional surgery (CS) for treatment of mycotic aortic aneurysm has rather high surgical morbidity and mortality rates. The use of endovascular aortic repair (EVAR) might simplify the procedure and provide a good alternative for this critical condition, but this remains to be proved. We analyzed all mycotic abdominal aortic aneurysm (AAA) cases treated by CS or EVAR in our institute and the reported cases treated by EVAR from the literature to determine the risk factors for aneurysm-related mortality and morbidity and to clarify the efficacy of the EVAR technique. METHODS AND RESULTS All relevant literature reports of EVAR management of mycotic AAA and all cases treated in our institute, 41 cases, were included and analyzed. Of the 20 cases treated by EVAR, one had early mortality (1/20, 5%); of the remaining 21 cases that received CS, the early mortality rate was 4.8% (1/21). Patients in the CS group had a higher late mortality rate than those in the EVAR group (45% vs. 10.5%, p<0.05). However, the 24-month actual survival rate and actuarial aneurysm-related event-free rate were 83.9+/-8.6% and 78.3+/-9.7%, respectively, for the EVAR group and did not significantly differ from the CS group (70.4+/-10.2% and 80.1+/-8.9%). The significant predictors for aneurysm-related mortality and morbidity were age, Salmonella species infection, and leukocytosis, and possibly aortoenteric fistula and shock, but not the EVAR or CS procedures themselves. CONCLUSION Compared with CS, EVAR might be an alternative strategy for managing mycotic AAAs.

The feasibility of endovascular aortic repair strategy in treating infected aortic aneurysms

BACKGROUND Open surgical treatment for an infected aortic aneurysm has a high rate of surgical morbidity and mortality and does not guarantee eradication of the infected nidus. The use of endovascular aortic repair (EVAR) might simplify the procedure and provide a good alternative for this critical condition, but this remains to be proved. This study assessed the efficacy and outcome of EVAR with an adjunctive antibiotic treatment strategy. METHODS We focused on the experiences and results of the management of infected aortic aneurysms with positive blood cultures. We drew the blood for culture study, immediately prescribed broad-spectrum antibiotics, performed EVAR procedures, and followed this with sensitive antibiotics and adjunctive procedures. RESULTS Twelve consecutive patients (mean age, 70 years) were included in this EVAR strategy. Three patients had thoracic, two thoracoabdominal, and the remaining seven had infected abdominal aneurysms. Ten Salmonella, one Staphylococcus, and one Streptococcus spp were identified. There was no hospital death. Three patients underwent computed tomography (CT)-guided drainage, and one underwent open laparotomy debridement. Mean follow-up was 24 months. One late death occurred but was unrelated to reinfection. All patients seemed well, with no evidence of EVAR graft infection at a mean follow-up of 23.6 months. CONCLUSIONS This small multi-institutional study summarizing the experiences of patients with an infected aortic aneurysm managed by EVAR and an aggressive antibiotic strategy revealed that this EVAR strategy might be a suitable approach to treating this disease. These favorable results may be typical for Salmonella infection, which was present in most of the patients. Further experience is needed to assess whether this therapeutic strategy works equally well in aneurysm infection caused by other organisms.

Comparative effects of the formulation of glyphosate-surfactant herbicides on hemodynamics in swine

Introduction. Most of the glyphosate-surfactant herbicides (GlySH) are formulated commercial products containing isopropylamine (IPA) salt of glyphosate (IPAG), variable amount of a surfactant, and water. Although glyphosate is only slightly toxic to rats, ingestion of GlySH may lead to severe effects, including death, in humans. We conducted a study to evaluate the cardiovascular effects of the components of GlySH. Methods. We used five groups of male piglets, each receiving infusion of normal saline (control), glyphosate in NaOH base, IPA, IPAG, and polyoxyethyleneamine (POEA), respectively. We chose concentrations that are similar to those in the commonly used GlySH (41% of IPAG and 15% surfactant). Results. We found that IPAG reduced the mean arterial blood pressure (MABP) and left-ventricular stroke work index (LVSWI) during the infusion, but both recovered gradually. It also decreased the cardiac index but increased the pulmonary capillary wedge pressure, central venous pressure (CVP), and mean pulmonary arterial pressure (MPAP). POEA infusion reduced the cardiac index and LVSWI, but not the MABP. It also increased the pulmonary capillary wedge pressure, CVP, MPAP, and pulmonary vascular resistance index. IPA increased the MABP, which was higher than those in the control, IPAG, and POEA groups. Glyphosate in NaOH base infusion did not affect the hemodynamics but slightly reduced the blood pH and base excess (BE) values. POEA and IPAG also resulted in metabolic acidosis, with lactate formation and decreased BE values. Conclusion. We conclude that both POEA and IPAG infusion affected hemodynamics and resulted in death in piglets, whereas glyphosate (NaOH base) had no similar effects.

A Rule-Based Decision-Making Diagnosis System to Evaluate Arteriovenous Shunt Stenosis for Hemodialysis Treatment of Patients Using Fuzzy Petri Nets

This paper proposes a rule-based decision-making diagnosis system to evaluate arteriovenous shunt (AVS) stenosis for long-term hemodialysis treatment of patients using fuzzy petri nets (FPNs). AVS stenoses are often associated with blood sounds, resulting from turbulent flow over the narrowed blood vessel. Phonoangiography provides a noninvasive technique to monitor the sounds of the AVS. Since the power spectra changes in frequency and amplitude with the degree of AVS stenosis, it is difficult to make a human-made decision to judge the degree using a combination of those variances. The Burg autoregressive (AR) method is used to estimate the frequency spectra of a phonoangiographic signal and identify the characteristic frequencies. A rule-based decision-making method, FPNs, is designed as a decision-making system to evaluate the degree of stenosis (DOS) in routine examinations. For 42 long-term follow-up patients, the examination results show the proposed diagnosis system has greater efficiency in evaluating AVS stenosis.

Endoscopic saphenous vein harvest decreases leg wound complication in coronary artery bypass grafting patients

AbstractBackground: Coronary artery bypass grafting (CABG) is the most common procedure performed in adult cardiovascular surgery. The most frequently used conduit is the greater saphenous vein. Using traditional methods, the complication rate of the leg is relatively high (up to 24%). To decrease the complication rate, we used the Endo‐Path to harvest the greater saphenous vein. Methods and Results: From May 1997 through March 1999, a total of 135 patients received the CABG operation. We excluded the patients who died immediately postoperatively or had concomitant surgical procedures. Sixty patients received the endoscopic saphenous vein harvest procedure (group A), while another 59 patients (group B) did not. No important differences were noted between the two groups in respect to the number of distal anastomoses, length of harvested vein, total surgical time, and length of ICU stay. However, the leg wound complication rate decreased from 20.3% to 5.0% (p < 0.001). Conclusions: Although the long‐term patency rate needs time to be proven, the endoscopic greater saphenous vein harvest method is an attractive and effective method.

Bilateral Persistent Sciatic Arteries Complicated with Acute Left Lower Limb Ischemia

Persistent sciatic artery (PSA) is a rare congenital malformation. In the early embryonic stage, the sciatic artery is the major blood supply for the lower limb bulb and is later replaced by the iliofemoral artery as the limb develops. Its failure to regress, sometimes associated with femoral arterial hypoplasia, and therefore becoming the dominant inflow to the lower extremity is called PSA. This anomaly is often associated with a higher rate of aneurysm formation or thromboembolic complications causing lower extremity ischemia. Here, we describe a 79-year-old male patient who presented with acute left lower extremity ischemia. He was treated initially with conventional embolectomy through inguinal and popliteal incisions. The bilateral PSA with thrombosed aneurysms was not identified at first on computed tomographic angiography. It was later diagnosed intraoperatively due to the discontinuity of the superficial femoral artery and popliteal artery found with embolectomy catheter, and was managed successfully with ePTFE graft bypass. Careful interpretation of the imaging study may be helpful in preoperative diagnosis.

Surgical Consideration of In Situ Prosthetic Replacement for Primary Infected Abdominal Aortic Aneurysms

OBJECTIVES To review our surgical experience of primary infected abdominal aortic aneurysms, with the aim of assessing the safety and durability of in situ prosthetic replacement. DESIGN Retrospective study in a university hospital. MATERIALS AND METHODS Thirty-four patients who underwent surgery for primary infected abdominal aortic aneurysms over the past 18 years were reviewed. Operative details and outcomes were recorded for analysis. RESULTS There were six suprarenal and 28 infrarenal infections. Salmonellae (18 patients) were the most common pathogens. Thirty patients underwent in situ prosthetic replacement, two underwent extra-anatomic bypass and two underwent endovascular repair. The surgical mortality for overall patients was 18%, and for patients reconstructed in situ, 17%. Among the 30 patients reconstructed in situ, four patients who underwent concomitant gastrointestinal procedures (e.g., repair of the duodenal defect) died. By contrast, 25 of 26 patients without gastrointestinal involvement survived surgery. After a median follow-up period of 58 months, two discharged patients who underwent in situ reconstruction died of late graft infection. CONCLUSIONS Our experience suggests that in situ prosthetic replacement can be performed safely with durable outcomes in the majority of patients with infected abdominal aortic aneurysms. Nevertheless, we advise caution when considering this technique with concomitant gastrointestinal procedures.

Bacteroides fragilis aortic arch pseudoaneurysm: case report with review

We present a case of 58-year-old woman with underlying diabetes mellitus, hepatitis C virus-related liver cirrhosis, and total hysterectomy for uterine myoma 11 moths ago, who was diagnosed ruptured aortic arch mycotic pseudoaneurysm after a certain period of survey for her unknown fever cause. After emergent surgery with prosthetic graft interposition, all her blood cultures and tissue cultures revealed pathogen with Bacteroides fragilis. Although mycotic aneurysms have been well described in literatures, an aneurysm infected solely with Bacteroides fragilis is unusual, with only eight similar cases in the literature. Here we reported the only female case with her specific clinical and management course and summarized all reported cases of mycotic aneurysm caused by Bacteroides fragilis to clarify their conditions and treatments, alert the difficulty in diagnosis, and importance of highly suspicious.

Residual Stenosis Estimation of Arteriovenous Grafts Using a Dual-Channel Phonoangiography With Fractional-Order Features

The residual stenosis estimation of an arteriovenous shunt is a valuable for evaluating outcomes of percutaneous transluminal angioplasty (PTA) treatment and surgical revision. This paper proposes a dual-channel phonoangiography (PCG) with fractional-order features to estimate the residual of stenosis estimation of arteriovenous shunt. The auscultation technique provides a noninvasive tool to monitor the degrees of arteriovenous grafts (AVGs). Then, support methods, such as the Burg autoregressive (AR) method and self-synchronization error formulation (SSEF), are used to extract fractional-order features between the loop site (L-site) and venous anastomosis site (V-site). Using 2-D patterns (nonlinear mapping), a generalized regression neural network (GRNN) is designed as a nonlinear estimate model to indicate the outcome of surgical revision or AVG stenosis upon routine monthly examinations. For 42 long-term follow-up patients, the results of examination show the proposed GRNN-based screening model efficiently estimates residual stenosis.