Efficacy and limitations of cyclophosphamide-induced tolerance against alphaGal antigen

In the present study, we have elucidated the efficacy of two cyclophosphamide (CP)-induced tolerance protocols for the induction of B-cell tolerance against Galalpha1-3Galbeta1-4GlcNAc (alphaGal) antigens. alpha1,3-galactosyltransferase-deficient (GalT-/-; H-2(b/d)) mice received with 1 x 10(8) AKR (alphaGal+/+ H-2k) spleen cells (SC) followed by 200 mg/kg CP, or alternatively followed by 200 mg/kg CP, 30 mg/kg Busulfan (BU) and 1 x 10(8) T-cell-depleted AKR bone marrow cells (BMC). The generation of both anti-alphaGal and anti-donor antibodies were completely suppressed, but normal antibody production against third party antigens was observed after BALB/c skin grafting in both groups of GalT-/- mice. In GalT-/- mice, treated with SC and CP, mixed chimerism was not observed. Cellular rejection was observed in grafted donor AKR hearts with an absence of humoral rejection, whereas humoral rejection was observed in untreated GalT-/- mice. On the other hand, long-term mixed chimerism and permanent acceptance of donor AKR skin graft and heart graft were achieved in GalT-/- mice treated with SC, CP, BU and BMC. These results demonstrate the efficacy of classical drug-induced tolerance in the induction of B-cell tolerance against alphaGal antigens. However, induction of stable mixed chimerism was required for the suppression of cellular rejection.

Characteristics of Peripheral Microembolization During Iliac Stenting: Doppler Ultrasound Monitoring

OBJECTIVE

To evaluate the characteristics of distal microembolic signals (MES) during iliac stenting using Doppler ultrasound monitoring.

DESIGN

Prospective clinical study.

METHODS

A 2-MHz probe was used to monitor continuously at the ipsilateral tibioperoneal trunks during technically and hemodynamically successful iliac stenting in 10 patients without infrainguinal occlusive lesion. MESs at guide-wire, balloon, or stent crossing (phase 1), predilatation (phase 2), stent deployment (phase 3), postdilatation (phase 4), and contrast medium or heparinized saline injection (at injection) were analyzed. Differentiation of gaseous emboli from particulate emboli was achieved by calculation of the sample volume length.

RESULTS

No distal embolic complications were observed. Five hundred and forty-one MESs were detected. The MES incidence and intensity in phase 3 were significantly higher than those in phase 1, phase 2, and phase 4 (p<0.05). The MES intensity at injection was significantly higher than that in each of four phases (p<0.0001).

CONCLUSIONS

Both the MES incidence and intensity were highest at stent deployment. Further study is required of microembolism during endovascular procedures in the lower extremities.

Involvement of cyclin D3 in liver metastasis of colorectal cancer, revealed by genome-wide copy-number analysis

The question of whether any genetic differences exist between primary and colorectal cancers (CRCs) and their metastatic foci is controversial. To look for genetic aberrations involved in metastasis of CRCs to the liver, we performed subtractive comparative genomic hybridization (CGH) experiments using paired samples from 20 CRC patients with primary tumors and synchronous or metachronous liver metastases. Relatively frequent gains in DNA copy number were detected at 6p, suggesting the presence of one or more metastasis-related genes in the region. Analysis of 11 CRC cell lines using array-based CGH (CGH-array) revealed one 6p candidate gene, CCND3. Quantitative reverse transcriptase-polymerase chain reaction experiments showed that CCND3 was significantly upregulated in liver-metastatic lesions compared with primary lesions (P<0.0152). In addition, immunohistochemical analysis of 120 primary CRC tumors demonstrated that cyclin D3 expression in the region of rolled edge was significantly associated with total recurrence, especially hematogenous recurrence (P=0.0307). The results implied involvement of cyclin D3 in liver metastasis of CRC, and the data may contribute to the development of a novel therapy or diagnostic agent for this currently intractable disease. Our experiments also confirmed the power of subtractive CGH and CGH-array analysis for identifying cancer-related genes.

Preoperative imaging of surrounding arteries by three-dimensional CT: is it useful for laparoscopic gastrectomy?

One of the difficulties in laparoscopic gastrectomy is the identification of the feeding artery of the stomach. Recently, 3-dimensional computed tomographic angiography has enabled the noninvasive visualization of arteries surrounding the stomach. Preoperative 3-dimensional computed tomographic angiography may facilitate laparoscopic gastrectomy by obtaining a road map of the arteries of the stomach. Twenty-nine cases of gastric cancer were evaluated using 3-dimensional computed tomographic angiography before surgery. Three-dimensional computed tomographic angiography showed the left gastric artery in 29 patients (100%), the right gastroepiploic artery in 29 patients (100%), the right gastric artery in 24 patients (82.8%), and the left gastroepiploic artery in 21 patients (72.4%). The aberrant hepatic artery was detected in 6 patients, and the variant of the right gastric artery and the variant of the left gastric artery were detected in 5 cases and 1 case, respectively. All laparoscopic gastrectomy procedures were performed successfully without conversion to open surgery. Preoperative 3-dimensional computed tomographic angiography was considered to be useful for laparoscopic gastrectomy.

Oral bacteria in the occluded arteries of patients with Buerger disease

OBJECTIVE

Recent studies have suggested that infectious organisms play a role in vascular diseases. In this study, to explore a possible link between oral infection and Buerger disease, we investigated whether oral (periodontal) bacteria were present in occluded arteries removed from patients with characteristic Buerger disease.

METHODS

Fourteen male patients with a smoking history who had developed characteristics of Buerger disease before the age of 50 years were included in this study. Occluded arteries, including superficial femoral (n = 4), popliteal (n = 2), anterior tibial (n = 4), and posterior tibial (n = 4) arteries, were removed and studied. A periodontist performed a periodontal examination on each patient and collected dental plaque and saliva samples from them at the same time. The polymerase chain reaction method was applied to detect whether seven species of periodontal bacteria--Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, Campylobacter rectus, Actinobacillus actinomycetemcomitans, Prevotella intermedia , and Prevotella nigrescens--were present in the occluded arteries and oral samples. In addition, arterial specimens from seven control patients were examined by polymerase chain reaction analysis.

RESULTS

DNA of oral bacteria was detected in 13 of 14 arterial samples and all oral samples of patients with Buerger disease. Treponema denticola was found in 12 arterial and all oral samples. Campylobacter rectus, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and Prevotella nigrescens were found in 14% to 43% of the arterial samples and 71% to 100% of the oral samples. A pathologic examination revealed that arterial specimens showed the characteristics of an intermediate-chronic-stage or chronic-stage lesion of Buerger disease. All 14 patients with Buerger disease had moderate to severe periodontitis. None of the control arterial samples was positive for periodontal bacteria.

CONCLUSIONS

This is the first study to identify oral microorganisms in the lesions of Buerger disease. Our findings suggest a possible etiologic link between Buerger disease and chronic infections such as oral bacterial infections.

[Perioperaive evaluation and management in vascular surgery especially for arteriosclerosis obliterans]

Perioperative cardiac event is relatively high in vascular surgery for arteriosclerosis obliterans (ASO), which is a major cause of postoperative death. ACC/AHA guideline and revised cardiac risk index (CRI) were advocated to assess risk factor stratification and to manage risk reduction. ACC/AHA guideline categorized all vascular procedures except carotid endarterectomy as high risk. Because almost all patients with ASO were aged and/or inactive, noninvasive testing was necessary in almost all patients by the stepwise bayesian strategy. Patients with revised CRI less than 1 point dominated about three fourths of all patients, whose prevalence and incidence of ischemic heart disease (IHD) were 2.5% and 1.3%, respectively. It seemed appropriate to apply noninvasive testing only for patients with revised CRI more than 2 points, and high risk indicated coronary angiography. Electrocardigrams obtained at baseline, immediately, and on the first 2 days after surgery appear to be cost-effective to diagnose IHD. Use of cardiac biomarkers was reserved for patients at high risk and those with clinical, or ECG evidence of myocardial infarction (MI). Beta-blockers or alpha-agonists were effective to reduce incidence of perioperative IHD. Although even optimal preoperative assessment and perioperative management, some patients will have perioperative MI.

Detection and localization of periodontopathic bacteria in abdominal aortic aneurysms

OBJECTIVES

We examined a possible link between periodontal disease and abdominal aortic aneurysm (AAA) by studying resected aneurysmal specimens from AAA patients for the presence of periodontopathic bacteria.

DESIGN

Prospective case control study.

MATERIAL AND METHODS

Thirty-two AAA patients were enrolled in the study. Periodontitis was classified according to the probing depth of periodontal pocket. Thirty-two aneurysmal walls, 16 mural thrombi, 5 atherosclerotic occlusive aorta and 5 control arterial tissue, were examined for 7 periodontal bacteria using polymerase chain reaction (PCR) method. The localization of the bacteria in the aneurysmal/atherosclerotic wall was determined by thromboendarterectomy.

RESULTS

All patients had periodontal disease, and most cases were severe. PCR examination of the aneurysmal specimens showed that 86% were positive for periodontal bacterial DNA. No bacteria were detected in the control specimens. The bacteria were found in both the intimal/medial layer and the adventitial layer of the aneurysmal wall but only in intimal/medial layer of the atherosclerotic occlusive aorta.

CONCLUSION

Periodontopathic bacteria were present in a high percentage of specimens of diseased arteries from AAA patients and were found throughout the whole aneurysmal wall. These bacteria may play a role in the development of AAAs and/or contribute to weakening the aneurysmal wall.

Detection of peripheral microemboli through collateral circulation by Doppler ultrasound monitoring-report of 2 cases

It is possible for a proximal arterial source to lead to distal atheroembolism even in the presence of chronic occlusive disease. However, no monitoring technique has been established regarding detection of peripheral emboli through the collateral circulation in the lower limbs. We report a 60-year-old woman and a 73-year-old man with iliac stenosis and complete occlusion of the ipsilateral superficial femoral artery in whom Doppler ultrasound successfully detected microembolic signals (MES) at the tibioperoneal trunk during percutaneous transluminal angioplasty (PTA) and stent placement. By means of continuous Doppler ultrasound monitoring, 29 MES were successfully detected immediately after PTA or stent placement (MESp) and 64 MES were detected immediately after the contrast medium administration (MESc). MESc generated significantly higher intensities (median 28, range 7 to 38) as opposed to MESp (median 21, range 5 to 35, p = 0.017). In addition, the intensity of MES after prestent PTA (n = 8, 25 dB, 12-35 dB) and stenting (n = 18, 22 dB, 9-35 dB) was significantly higher than that of MES after poststent PTA (n = 3, 13 dB, range; 5-16 dB), respectively (p = 0.041, p = 0.034). Iliac PTA and stent placement were successful. Ankle/brachial pressure index and the symptoms improved in both patients, who showed no embolic symptoms after the procedure. This study suggested that it was possible to detect peripheral microemboli through the collateral circulation by Doppler ultrasound monitoring and that this technique would be helpful to investigate the mechanism of embolization in patients with PTA and stent placement.

Treatment of Three Pancreaticoduodenal Artery Aneurysms Associated with CœLiac Artery Occlusion and Splenic Artery Aneurysm: A Case Report and Review of the Literature

A case of three pancreaticoduodenal artery (PDA) aneurysms associated with coeliac artery occlusion and a concomitant splenic arterial aneurysm is described. Surgical treatment was used because it was anticipated that the hepatic blood supply would be obstructed completely if percutaneous transluminal embolization for three PDA aneurysms were performed. Splenectomy in continuity with the splenic artery aneurysm and PDA aneurysmectomies were performed, and infrarenal abdominal aorto-splenic artery bypass was accomplished using a 6mm ringed expanded polytetrafluoroethylene graft. The postoperative course was uneventful. Graft patency and successful aneurysm ablation were confirmed using MRA and intravenous DSA. Arterial histology revealed segmental arterial mediolysis. At 2-year follow-up, the patient was well and asymptomatic. A literature review of PDA aneurysms is presented.

[Two-stage repair of the transposition of great arteries with interruption/coarctation of the aorta]

We report on 10 patients who underwent two-stage repair of transposition of the great arteries (TGA) with interruption (IAA) or coarctation (CoA) of the aorta. First, an operation for aortic arch reconstruction was performed: Blalock-Park with pulmonary artery banding (PAB) for IAA (5 patients), subclavian flap with PAB for CoA (4 patients) and end-to-end anastomosis without PAB (1 patient). All survived the first operation and had no significant pressure gradient with good growth of the ascending aorta, except for the 1 case without PAB. Half of the 8 patients who underwent PAB developed migration of the PAB. The arterial switch operation (ASO) was performed 0.7-12.6 (5.6+/-4.7) months after the first surgery. One patient with an abnormal coronary artery tract was lost after ASO. Five developed pulmonary artery stenosis and 1 developed supra-aortic stenosis late after ASO. Two patients need reoperation, 1 for supra-aortic stenosis, and the other for reCoA. Two-stage repair for TGA with IAA/CoA is still a useful method with a good operative result. However, strict follow-up is necessary because of the high frequency of late morbidity.

Relationship between CDX2 gene methylation and dietary factors in gastric cancer patients

Epigenetic gene silencing through DNA methylation is one of the important steps in the mechanism underlying tumorigenesis, including in the stomach. Past lifestyle factors of cancer patients, such as intake of vegetables, are very important in affecting gastric carcinogenesis. However, the relationship between DNA methylation and past dietary habits in cancer patients remains largely unknown. The CDX2 homeobox transcription factor plays a key role in intestinal development, but CDX2 is also expressed in most of the intestinal metaplasia and part of the carcinomas of the stomach. We analyzed the methylation status of the CDX2 5' CpG island in gastric cancer cell lines by methylation-specific PCR (MSP), and then CDX2 mRNA was found to be activated after 5-aza-2'-deoxycytidine treatment of the methylation-positive cells. We further examined the methylation status of CDX2 in primary gastric carcinomas by MSP and compared it with the past lifestyle of the patients, including dietary habits. Methylation of CDX2 was found in 20 (34.5%) of the 58 male patients and one (6.7%) of the 15 female patients. Since the methylation frequency was low in the female patients, the analysis was performed only on the male cases. CDX2 methylation was correlated with the decreased intake of green tea and cruciferous vegetables, and also with full or overeating habits. These findings are consistent with epidemiological observations on gastric cancer. We also analyzed the methylation status of p16/INK4a and hMLH1, but their frequencies were not associated with dietary factors or other lifestyle factors. Thus, diet could be an important factor determining the methylation status of genes such as CDX2 and the resultant aberrant expression of genes involved in carcinogenesis.

Preliminary report of multi degrees of freedom forceps for endoscopic surgery

Laparoscopic suturing requires more complex techniques than conventional open surgery, because of the limited degrees of freedom of endoscopic devices. The prototype multi degrees of freedom forceps was developed with a concept of a flexibility that frees us from the restriction on suturing during endoscopic surgery. It was designed for a needle holder. We calculated the movement of the forceps' distal joint at the time of horizontal suturing. The learning curve was also investigated for ten surgeons. The device was clinically applied in several surgeries. We could perform suturing freely using this prototype forceps at any point and in any directions. The learning curve had its peak within five training sessions, and may be mastered during about ten training sessions. All clinical applications were successfully achieved. With the increased degree of freedom for forceps, the operability for endoscopic surgery was improved.

Long-term results of aorta-superior mesenteric artery bypass using a new route

PURPOSE

Several methods of revascularization after mesenteric ischemia have been proposed. Using a new route, we performed retrograde loop bypass grafting to the superior mesenteric artery (SMA) with a ringed expanded polytetrafluoroethylene (ePTFE) graft.

METHODS

We anastomosed the graft to the infrarenal aorta, which ran behind the left renal hilum, turned ventral, and was anastomosed to the SMA in an antegrade fashion hemodynamically. Five patients underwent this procedure, which resulted in remarkable symptomatic relief.

RESULTS

There were no postoperative deaths or serious complications, although some patients suffered paralytic ileus. All of the grafts remained patent during long-term follow-up, ranging from 17 to 72 months (mean: 37.8 months). Postoperative angiograms showed good configuration of the graft, which did not compress the renal vessels.

CONCLUSION

Infrarenal aorta-SMA bypass relieved mesenteric ischemia and achieved good long-term graft patency. Thus, we consider it to be an effective and durable vascular procedure to reduce postoperative mortality and morbidity.

SOFA score predicts postoperative outcome of patients with colorectal perforation

BACKGROUND/AIMS

Colorectal perforation remains a life-threatening condition associated with high mortality. Various factors and operative procedures have been discussed in regard to prediction of outcome, and several scoring systems have been proposed to predict the outcome of critically ill patients. The present study was undertaken to identify factors and determine predictive scoring systems for the postoperative outcome of patients with colorectal perforation.

METHODOLOGY

Between January 1996 and December 2000, 45 consecutive patients underwent emergency operation for colorectal perforation. Twelve patients (26.7%) died in hospital. The correlation of outcome with various preoperative factors, APACHE II and SOFA scores were assessed retrospectively.

RESULTS

Univariate analysis showed that outcome was significantly related to maximum SOFA score (p=0.0069). Multivariate logistic regression analysis demonstrated that the maximum SOFA score was an independent predictor (p=0.016). Serum creatinine level (p=0.013) and platelet count (p=0.036) were associated with patient outcome in the SOFA score. Patients with a SOFA score higher than 7 had a greater risk of hospital death (p=0.0085).

CONCLUSIONS

The maximum postoperative SOFA score is a useful predictor of the outcome from surgery for colorectal perforation.

Treatment strategy for Boerhaave's syndrome

Esophageal rupture is a potentially mortal condition. Rapid and correct diagnosis, and urgent surgical treatment with esophagectomy is indicated, but conservative and other surgical treatments have also been reported recently. The treatment strategies for esophageal rupture are discussed here, based on our experiences with four cases during the last 10 years. They were admitted urgently and each was treated by a different method. Three of them underwent emergency operations, one undergoing primary closure of the ruptured esophagus, another received a T-tube insertion from the ruptured site with omental flap, and the third an esophagogastrectomy. The fourth case was treated conservatively. All patients survived and were discharged 36-144 days post treatment. One of them was readmitted for debridement of necrotic rib. In conclusion, the prompt and accurate diagnosis of esophageal rupture is crucial for a subsequent successful treatment. Conservative treatment or operation including esophagectomy will be determined by the severity of the condition.

Is drip infusion cholecystocholangiography (DIC) an acceptable modality at cholecystectomy for cholecystolithiasis, considering the frequency of bile duct maljunction and intraoperative bile duct injury?

BACKGROUND/PURPOSE

Knowledge of the configuration of the extrahepatic bile duct is indispensable to avoid bile duct injury during cholecystectomy. Various methods of examining the biliary tract have been developed; however, the most appropriate preoperative diagnostic modality at cholecystectomy for cholecystolithiasis has not yet been reported. Considering the frequency of bile duct maljunction (BDM) and operative bile duct injury, in addition to the cost and invasiveness of the various examination methods, we evaluated the usefulness of drip infusion cholecystocholangiography (DIC) as the optimal method of examination at cholecystectomy for cholecystolithiasis.

METHODS

Preoperative diagnostic accuracy of BDM was analyzed in relation to operative bile duct injury using 469 patients with benign biliary diseases who was diagnosed with DIC and endoscopic retrograde cholecystography and underwent cholecystectomy. BDM was classified according to Hisatsugu criteria.

RESULTS

Out of 469 consecutive patients who underwent a cholecystectomy for biliary stones between January 1, 1995, and September 30, 1998, at Ohta Nishinouchi General Hospital, 21 (4.48%) had a cystic duct maljunction (CDM) and 12 (2.56%) had an aberrant bile duct (ABD). The most common variants were types C and D for CDM, and types II and III for ABD, according to Hisatsugu's classification. Fourteen patients (42.4%) were diagnosed before the surgery; 13 of them received preoperative endoscopic retrograde cholangiography (ERC), and the remaining patient underwent preoperative drip infusion cholecystocholangiography (DIC). Nineteen patients could not be correctly diagnosed based on their preoperative examinations, but were diagnosed during surgery. Operative bile duct injury occurred in 1 patient (0.2%) whose maljunction could not be diagnosed before the operation.

CONCLUSIONS

Taking into account the medical cost and invasiveness, and the frequency of BDM and related bile duct injuries, we conclude that DIC is an acceptable preoperative diagnostic modality to employ at cholecystectomy for cholecystolithiasis. Knowledge of the configuration of the extrahepatic bile duct is indispensable to avoid bile duct injury during cholecystectomy. Various methods of examining the biliary tract have been developed; however, the most appropriate preoperative diagnostic modality at cholecystectomy for cholecystolithiasis has not yet been reported. Considering the frequency of bile duct maljunction (BDM) and operative bile duct injury, in addition to the cost and invasiveness of the various examination methods, we evaluated the usefulness of drip infusion cholecystocholangiography (DIC) as the optimal method of examination at cholecystectomy for cholecystolithiasis.

Surgical strategy for treating renal cell carcinoma with thrombus extending into the inferior vena cava

OBJECTIVE

A surgical strategy for treating malignant renal tumors with thrombus extending into the inferior vena cava (IVC) was assessed.

METHODS

We retrospectively reviewed the records for all patients with renal cell carcinoma (RCC; n=30) or Wilms tumor (n=1) with tumor thrombus extending into the IVC who underwent surgical intervention at our institution between January 1980 and December 2001. Tumors were classified preoperatively according to the cephalad extension of thrombus, and intraoperative procedures were selected on the basis of degree of extension. Patients with RCC underwent radical nephrectomy and removal of thrombus with (n=11) or without (n=19) IVC resection. Partial normothermic cardiopulmonary bypass without cardiac arrest was used in 4 patients. The Pringle maneuver was performed in 8 patients. Infrarenal abdominal aortic cross-clamping was used in 8 patients to maintain systemic blood pressure. IVC cross-clamping and the Pringle maneuver were performed in 5 patients with suprahepatic thrombus extension. Temporary placement of a filter in the IVC or plication of the IVC above the hepatic vein was performed before hepatic mobilization, to decrease the risk for pulmonary embolism.

RESULTS

One patient died intraoperatively of pulmonary embolism. Postoperative complications occurred in 11 patients; all resolved with conservative therapy. The postoperative duration of survival in patients with RCC was 37 +/- 44 months (range, 4-180 months); the 5-year survival rate was 42%.

CONCLUSION

Aortic cross-clamping during IVC occlusion prevented hypotension and maintained hemodynamic stability that has required bypass in other series. This surgical treatment with the less extensive approach could result in long-term survival of patients with RCC in whom tumor thrombus extends into the IVC. We recommend that radical nephrectomy and tumor thrombectomy, with or without caval resection, be performed in these patients, with less invasive additional maneuvers.

Hand-assisted laparoscopic total gastrectomy for early gastric cancer

Laparoscopy-assisted distal gastrectomy has been applied to the treatment of early gastric cancer in Japan. However, there have been few reports on the laparoscopy-assisted total gastrectomy mainly because of the difficulty of the procedure. Here, we report a series of cases where hand-assisted laparoscopic total gastrectomies were performed successfully. The mobilization of the greater curvature was performed laparoscopically. About 7-cm mini-laparotomy was made at the epigastrium and duodenal transection was performed with linear stapler. After dissection of suprapyloric and anterosuperior lymph nodes was performed through the mini-laparotomy, dissection of lymph nodes along the celiac artery, and the left gastric artery was performed by hand-assisted laparoscopic surgery. Roux-en-Y reconstruction was performed through the mini-laparotomy. We successfully performed this procedure in 5 patients. The mean operating time and blood loss were 275 minutes and 177.5 mL, respectively. Hand-assisted laparoscopic total gastrectomy is suitable and feasible for early gastric cancer.

Complete resection of leiomyosarcoma of the suprarenal inferior vena cava without caval replacement

Objective: To successfully treat leiomyosarcoma of the suprarenal segment of the inferior vena cava (IVC) by section without caval replacement.

Methods: Multiple occlusive clamps were used to maintain haemodynamic stability. Measurement of the stump pressure of the distal IVC and both renal veins was employed to evaluate venous congestion.

Results: Use of these techniques allowed avoidance of suprarenal IVC reconstruction in our patient, who had well-developed collateral veins.

Conclusions: Our experience indicates that reconstruction is not always mandatory.

Vascular Closure System Type of Nonpenetrating Arcuate-Legged Titanium Clips for Graft-Artery and Graft-Graft Anastomoses: Review of Our Clinical Experience

PURPOSE

To assess the durability of Vascular Closure System (VCS) clips for graft-artery and graft-graft anastomoses.

METHODS

The subjects were 100 consecutive patients, who had undergone vascular procedures in which VCS clip application was attempted for anastomoses. The operative indications were arteriosclerosis obliterans in 69 patients, aortic aneurysm in 26, and other disorders in 5. Large clips were used for both graft-artery and graft-graft anastomoses, and medium-sized clips were used for the smaller caliber femoral or popliteal arteries.

RESULTS

Vascular Closure System clips could not be applied to anastomose the graft to the artery in 13 patients because the arterial wall was too thick or stiff. Anastomosis was accomplished without any problems in 80 patients, although suture-line bleeding occurred in 7 patients. This was ameliorated by an additional clip in four patients, but interrupted sutures were needed to seal the anastomosis in the other three patients. The 1-, 3-, and 5-year cumulative primary patency rates were 98.7%, 97.4%, and 87.7%, respectively. There were two graft failures and two anastomotic aneurysms.

CONCLUSION

Vascular Closure System clips were useful to coapt a prosthetic graft to an artery unless the arterial wall was thicker than 2 mm or calcified. Thus, VCS clips could be durable enough for graft-artery anastomoses in the iliac or popliteal region.

Management for fistula-in-ano with Ginseng and Tang-kuei Ten Combination

BACKGROUND

Non-operative management for patients with fistula-in-ano in infancy using a traditional herbal medicine Ginseng and Tang-kuei Ten Combination (GTTC) is described.

METHODS

A total of 22 patients with peri-anal abscess or fistula-in-ano were treated with GTTC. Eighteen patients showed no improvement using the conventional non-operative management (frequent curettage of abscess cavity), after which administration of GTTC was commenced. The other four patients received GTTC from the beginning of their treatment. A dose of 0.1-0.2 g/kg of GTTC was given orally twice a day. The period between onset of peri-anal abscess and the commencement of GTTC (pre-GTTC period) was compared to the period until remission after administration of GTTC (post-GTTC period). The relationship between the GTTC dose, age at onset of peri-anal abscess, post-GTTC period, and relapse rates were investigated.

RESULTS

Twenty-one patients reached remission, but a 4-year-old boy failed to reach remission and he required fistelectomy. Pre-GTTC periods were from 11 days to 3 years (median 50 days) and statistically longer than post-GTTC periods (4-65 days, median 7 days). There was a reverse correlation between the age at onset of peri-anal abscess and post-GTTC period (r = -044, P < 0.05). There was no statistical correlation between the dose of GTTC and post-GTTC period. Five patients showed relapse after discontinuing GTTC, all of them could be resolved with augmentation of the dose. The onset of peri-anal abscess in patients who relapsed were all < 3 months of age.

CONCLUSION

Ginseng and Tang-kuei Ten Combination seemed to accelerate the recovery of patients with fistula-in-ano in infancy.

Distributing pattern of the bile duct of the caudate lobe on computed tomography with drip infusion cholangiography and its surgical significance

BACKGROUND/AIMS

It is important to recognize the distribution of the bile ducts in the caudate lobe of the liver for the hepato-biliary surgery. To map the spatial relationship between the bile ducts and the liver parenchyma under physiological conditions, we performed an anatomical analysis of them using computed tomography combined with drip infusion cholangiography (DIC-CT).

METHODOLOGY

We identified the bile ducts in the caudate lobe, which was divided into the Spiegel lobe, paracaval portion, and caudate process, with DIC-CT. We then investigated their number and confluence pattern in 132 patients without any abnormality in the hilar bile ducts.

RESULTS

The mean number of the bile ducts in the caudate lobe was 2.68 per liver. In the Spiegel lobe, the branches drained into the left hepatic duct system in about 83%. The confluence of the paracaval branch was the left hepatic duct, right hepatic duct, and posterior segmental branch, all with the same frequency of approximately 30%. Almost all of the caudate process branches (92.4%) drained into the posterior segmental branch.

CONCLUSIONS

DIC-CT is a useful method for the anatomical analysis of the intrahepatic bile ducts under physiological conditions, and we obtained novel and important findings for surgery.

An animal model study to clarify and investigate endoscopic tissue coagulation by using a new monopolar device

BACKGROUND

The purpose of this study was to evaluate a new device for endoscopic monopolar electrocoagulation and to develop ablative techniques by using this new device.

METHODS

The new device consists of an overtube with a wire mesh electrode in an oval opening in the distal end and a balloon at the distal end. High-frequency electrical current was applied in 5 animal (swine) esophagi by using this specially designed monopolar electrocoagulation device. A total of 32 "lesions" were ablated by using blend electrosurgical waveforms for different time durations. The esophagi were then resected for histopathologic evaluation.

RESULTS

Histopathologic study of the ablated lesions demonstrated that, by using the monopolar electrocoagulation device, different levels of degeneration of the mucosa and submucosa were achieved. The method for use of the device is fast and easy to apply.

CONCLUSIONS

The ablative procedure with the new overtube device is minimally invasive, clearly feasible, and easy to apply. This new device potentially can be used in patients for tissue ablation.

Usefulness of peak-to-peak pulsatility index in infrainguinal bypass graft surveillance

PURPOSE

We conducted this study to find out whether the peak-to-peak pulsatility index (PPI) predicted graft failure and which factors affected the PPI.

METHODS

Color-duplex sonography was used to take 520 scans of 74 infrainguinal bypasses, 62 of which were femoropopliteal bypasses and 12 of which were femorocrural bypasses. Vessel diameter and velocity waveform were measured in the graft as well as in the proximal and distal arteries.

RESULTS

There were 13 cases of graft failure. The PPI in the mid-graft was significantly different in the normal group (12.30 +/- 8.77) and the graft failure group (4.17 +/- 1.79). A PPI of less than 7.0 in the mid-graft was defined as graft failure, with a sensitivity of 96.0% and a specificity of 77.6%. There was no correlation between the graft diameter and the PPI. The average mode frequency was inversely correlated with the PPI (PPI = 44.8 x Mode F(-1) + 3.50, correlation co-efficient: 0.78).

CONCLUSION

One point measurement of the PPI in the mid-graft could be a simple and useful parameter for diagnosing graft failure, based on our finding that the waveform was very similar in the proximal artery, the entire graft, and the distal artery. PPI was inversely correlated with average mode frequency because reverse flow decreased or diminished when a significant stenosis existed.

The role of the rectal branches of pelvic plexus in defecation and colonic motility in a canine model

The parasympathetic nerves regulate colonic motility and defecation. The vagal nerve controls the right colon and the pelvic nerve permeates the left colon and rectum via the rectal branches of the pelvic plexus (RBPP). This investigation aimed to measure the functional changes of the colon and rectum after RBPP-transection for over six months. RBPP-transection was performed in 15 dogs. Five dogs each were sacrificed immediately, one month, and six months after RBPP-transection. The stool condition, colorectal transit, defecation reflex, colorectal response to electrical stimulation, and pathological degeneration was investigated prior to, one month after, and six months after RBPP-transection. Four of the 5 dogs observed had loose stool one month after RBPP-transection, and one of the 3 had recovered six months later. Half transit time (HTT) at transverse colon got longer in six of the 8 in one month. Six months later, HTT got shorter in three of the 4 than that of one month. Defecation reflex was not observed one month after RBPP-transection, but noted in two of the 5 six months later. These results may suggest that vagal nerve compensates for the oral site of the left colon after denervation of the pelvic nerve which is originally distributed.

Varicose bleeding after liver transplantation in a patient with severe portosystemic shunts

Recipients for liver transplantation often have portosystemic shunts due to portal hypertension. It is an important problem whether such shunts should be ligated during operations. Ligating the shunts seems of benefit for increasing portal blood flow to the liver, but it is sometimes difficult technically, and it is invasive to the patient. We experienced a recipient with huge portosystemic shunts and no esophageal varices before living-related liver transplantation. Some shunts were ligated during operation to increase portal blood flow to the graft. Unfortunately, the patient suffered severe bleeding from esophagogastric varices after he underwent retransplantation owing to accidental liver failure. Based on our experience, extreme care should be exercised to avoid varicose bleeding after ligating the portosystemic shunts of liver transplantation patients.

Transanal Laser Doppler Flowmetry to Assess Microcirculation in the Upper Rectum During Abdominal Aortic Aneurysmectomy

PURPOSE

Fatal ischemic colitis can develop after abdominal aortic aneurysmectomy. We investigated the effectiveness of transanal laser Doppler flowmetry (LDF) for assessing microcirculation in the rectal mucosa during aneurysm repair.

METHODS

The subjects were 17 patients who underwent abdominal aortic aneurysmectomy. A Doppler laser and Doppler probe were mounted on a rectoscope, which was inserted into the anus, and rectal flux values were obtained by a flowmeter.

RESULTS

The mean flux value during aortic clamping was 146 +/- 35.6 perfusion units (PU) in patients with sufficient collateral circulation to the upper rectum and 58.3 +/- 19.4 PU in patients with insufficient collateral circulation ( P << 0.01). The LDF values and inferior mesenteric artery stump pressure measurements were well correlated ( r = 0.86).

CONCLUSION

Transanal rectal LDF is useful for continuously assessing microcirculation in the rectal mucosa during abdominal aneurysmectomy, and the data obtained with this method may reflect whether a collateral pathway to the upper rectum exists.

Increased expression of CEA and MHC class I in colorectal cancer cell lines exposed to chemotherapy drugs

PURPOSE

Cancer-specific immunotherapy holds great promise as an emerging treatment for advanced colorectal cancer and may be combined with standard chemotherapy to provide a synergistic inhibitory action against tumor cells. To examine the interrelationship between the immune system and chemotherapy, we studied the induction of both CEA, a tumor-associated antigen, and MHC class I, a major component of the antigen presenting system, in response to a number of chemotherapeutic agents.

METHODS

The effect of a selection of standard chemotherapeutics on MHC class I and CEA expression in human colorectal cancer cell lines was determined by flow cytometry and semi-quantitative RT-PCR. In addition, studies using mice bearing tumors derived from an injected murine colon cancer cell line were performed to determine if alteration in MHC class I expression occurs in vivo following continuous infusion of chemotherapeutic agents into the peritoneal cavity, as well as to facilitate correlations between expression of this factor and therapeutic effectiveness.

RESULTS

All anti-cancer drugs examined, when given at IC50 values, induced expression of MHC class I protein in the human colon cancer cell line, COLO201. However, expression of CEA mRNA was only induced upon exposure to 5-FU, in contrast to obscure induction following CDDP and SN-38 treatment. Combined treatment with 5-FU and CDDP gave additional effect on CEA expression in COLO201 cells. Regarding the in vivo studies in mice, the size of the murine colon cancer cell-derived tumors was reduced only in response to treatment with CDDP, which also mediated the highest induction of MHC class I expression.

CONCLUSION

These results suggest that chemotherapeutic agents trigger the immune system and cancer-specific immunotherapy may be effective when used in combination with systemic chemotherapy.

Synthesis of oligonucleotide derivatives containing a bis-pyrene residue in the main chain

The oligonucleotide having the bis-pyrene residue in the main chain was synthesized. The preparation of the bis-pyrene was started from the conversion of 2,2-bis-(bromomethyl)-1,3-propanediol into the protected bis-amino derivative. The reaction of the bis-amino derivative with 1-pyrenebutyric acid using DCC/HOBT afforded the desired bis-pyrene. This compound was then converted to the protected phosphormidite. The oligonucleotides possessing the bis-pyrene were synthesized by using the amidite. The oligonucleotides having the bis-pyrene residue can bind to DNA sequence in an aqueous solution to give the duplex with comparable thermal stability as that of the unmodified DNA/DNA duplex. The significantly enhanced pyrene-excimer fluorescence was observed upon hybridization of the bis-pyrene modified oligonucleotides with DNA.

CDX2, a homeobox transcription factor, upregulates transcription of the p21/WAF1/CIP1 gene

The CDX2 homeobox transcription factor plays key roles in intestinal development and homeostasis. CDX2 is downregulated during colorectal carcinogenesis, whereas overexpression of CDX2 results in growth inhibition and differentiation of colon carcinoma and intestinal cells. However, the means by which CDX2 functions remain poorly understood. p21/WAF1/CIP1 is one of the cyclin-dependent kinase inhibitors. In addition to its role in cell cycle control, p21 plays critical roles in differentiation and tumor suppression. The overlapping in both the expression and function of CDX2 and p21 in the small intestine and colon strongly suggests a link between these two genes. By means of luciferase reporter and electrophoretic mobility shift assays, we show here that CDX2 transactivated and physically interacted with the promoter of p21 in a p53-independent manner. Moreover, overexpression of CDX2 increased the mRNA expression of p21 in HT-29 colon carcinoma cells, as demonstrated by reverse transcription-polymerase chain reaction. These data suggest that p21 is a transcriptional target of CDX2. Our results may thus provide a new mechanism underlying the functions of CDX2.

Effect of dai-kenchu-to on obstructive bowel disease in children

The aim of this study was to evaluate the effects of a traditional Chinese herbal medicine, dai-kenchu-to (DKT), on obstructive bowel diseases in children. We have treated 46 pediatric patients with various obstructive bowel diseases with DKT: six patients with postoperative ileus, 12 with large abdominal surgery (including three neonates), one with ano-rectal anomaly, three with Hirschsprung's disease, two with functional bowel obstructions, one with SMA syndrome, and 21 patients with chronic constipation. DKT (0.1-0.15 g/kg) was mixed with 5-10 ml of warm water, and was given orally two to three times a day. DKT was effective for 39 patients (85%) and their clinical symptoms improved. DKT was ineffective in seven patients: two with postoperative ileus, two with Hirschsprung's disease, and three with chronic constipation. DKT had mild but significant effects for various obstructive bowel diseases in children, while no side effects were encountered. Our current strategy for pediatric patients with obstructive bowel disease is to use DKT first and then test its efficacy. If DKT is effective, the regimen is continued. However, in cases where DKT is not effective, we will consider laparotomy or will further investigate the illness.

Amlodipine modulates THP-1 cell adhesion to vascular endothelium via inhibition of protein kinase C signal transduction

Inflammatory responses play an important role in atherosclerosis. To critically assess the effect of dihydropyridines in inflammatory reactions, we conducted a monocyte-endothelial adhesion assay with monocytic THP-1 cells treated with amlodipine under flow conditions in vitro. THP-1 cells were incubated in the presence of amlodipine (10 micromol/L) for 48 hours and then perfused over activated (interleukin-1beta, 10 U/mL, 4 hours) human umbilical vein endothelial cells. The adhesion of THP-1 cells was significantly reduced after amlodipine treatment (P<0.001); however, flow cytometric analysis reveled that the expression levels of integrins in THP-1 cells were not significantly altered. Furthermore, Western blotting analysis of THP-1 cell lysates revealed that translocation of RhoA from the cytosol to the membrane was significantly diminished after amlodipine treatment. In addition, activation of protein kinase C-alpha and -beta, as well as intracellular calcium influx, induced by phorbol 12-myristate 13-acetate, was diminished after amlodipine treatment. Pretreatment of THP-1 cells with calphostin C, a potent inhibitor of protein kinase C, significantly reduced THP-1 adhesion to vascular endothelium, whereas activation of beta1-integrin was reduced after amlodipine treatment in THP-1 cells, based on the immunoreactivity of an activation-specific antibody for beta1-integrin. Similar inhibitory effects were observed when we used freshly isolated peripheral blood mononuclear cells. These findings suggest a potential role for amlodipine in monocyte-endothelial interactions by modulation of protein kinase C- and RhoA-dependent mechanisms, which might account for its vascular protective effects.

Development and clinical application of semi-loop-shaped retractor for gasless laparoscopic surgery

BACKGROUND

Gasless laparoscopy has the advantage of avoiding the risk inherent in pneumoperitoneum, but has not gained widespread popularity because of limited exposure of the operative field. Improved retraction devices are therefore needed.

METHODS

A loop-shaped metallic retractor was designed for planar lifting of the anterior abdominal wall. Four types of retractor (5/6-, 3/4-, and 1/2-circle with rod at 90 degrees, and 1/2-circle with rod at 97 degrees ) were studied in 15 pigs. The device was then used for 47 patients.

RESULTS

The 1/2-circle was the most smoothly inserted retractor and was significantly safer than the 5/6-circle (p < 0.05, Fisher's exact probability test). The 1/2-circle with rod at 97 degrees was utilized for clinical cases. This retractor can be readied within 1 min and was used successfully for all operations.

CONCLUSIONS

This new retractor for gasless laparoscopic surgery provides good exposure and has the potential to enhance the performance of advanced laparoscopic surgery.

Tumor-specific immunological recognition of frameshift-mutated peptides in colon cancer with microsatellite instability

Colorectal cancers with microsatellite instability (MSI+ CRCs) caused by dysfunction of DNA mismatch repair have unique clinicopathological characteristics including good prognosis with T-cell infiltration in tumor. To identify tumor antigens that induce immune response against MSI+ CRC, SEREX (serological analysis of recombinant cDNA expression cloning) was applied. By screening a lambda phage cDNA library constructed from three MSI+ CRC cell lines with serum from a patient with MSI+ CRC with abundant T-cell infiltrates in tumor, 64 antigens were isolated. Immunogenicity of each antigen was evaluated by screening sera from patients with various cancers and from healthy individuals, and specific IgG antibodies (Abs) for 49 antigens were detected only in MSI+ CRC patients. A frameshift mutation in the repetitive G sequences (microsatellite) in the coding region of CDX2, one of the identified antigens, was found in the tumor tissue of the patient who had anti-CDX2 serum Ab. The Ab recognized both the COOH-terminal tumor-specific peptides created by the frameshift mutation and the NH(2)-terminal normal peptides of CDX2 when Western blot analysis was performed using various bacterial recombinant CDX2 proteins including the normal and altered peptides, which indicated that immune response could be raised against tumor-specific peptides generated through MSI. The anti-CDX2 Ab was detected only in the patient with the CDX2 frameshift mutation in tumor and disappeared 7 years after the curative resection, suggesting that this immune response may also be useful as a tumor marker. No altered subcellular localization and transcription ability was demonstrated in the mutated CDX2, although decreased expression was suggested in immunohistochemical analysis. Therefore, tumor-specific peptides generated by MSI may be involved in antitumor immune responses and may be useful for the development of diagnostic and therapeutic methods for patients with MSI+ CRC.

Evaluation of buttock claudication with hypogastric artery stump pressure measurement and near infrared spectroscopy after abdominal aortic aneurysm repair

OBJECTIVE

We explored the usefulness of intraoperative measurement of hypogastric artery (HGA) stump pressure (HGA-SP) and postoperative near infrared spectroscopy (NIRS) in evaluating buttock claudication (BC) after abdominal aortic aneurysm (AAA) repair.

DESIGN

Retrospective clinical study.

PATIENTS AND METHODS

Twenty patients who were undergoing AAA repair were enrolled. The HGA was ligated bilaterally in 5 patients, unilaterally in 12, and preserved in 3. The HGA-SP was measured intraoperatively. Postoperatively, NIRS was used to evaluate buttock muscle ischemia during walking.

RESULTS

Six patients had unilateral and 1 bilateral BC after AAA repairs. The median HGA-SP brachial pressure index (HBI) was 0.62 (range: 0.45-0.64) in 8 claudicating buttocks and 0.76 (range: 0.63-0.90) in 13 asymptomatic buttocks (p < 0.0005). The HBI was <0.65 in all claudicating buttocks, whereas it was >0.63 in asymptomatic buttocks. In all 8 claudicating buttocks, NIRS showed the ischemic pattern with recovery time lasting more than 240 s.

CONCLUSIONS

An HBI below 0.65 may be a predictor of BC after AAA repair. NIRS appears to be a useful noninvasive method for evaluating BC after AAA.

Early esophageal carcinoma: endoscopic ultrasonography using the Sonoprobe

BACKGROUND

Almost all cases of superficial esophageal carcinoma are curable by endoscopic mucosal resection (EMR), but a precise diagnosis of the depth of tumor invasion is necessary to assess the indication for EMR. Although endoscopy has a high rate of accuracy for diagnosing the depth of tumor invasion, it depends on the experience of the examiner in interpreting surface information of the lesions. Today, endoscopic ultrasonography (EUS) is one of the most powerful techniques for obtaining objective tomographic images of a tumor. The high-frequency ultrasound probe is appropriate for EUS in cases of superficial esophageal carcinoma because of its excellent near-field resolution that provides precise ultrasound images under direct control of the endoscope.

METHODS

We performed EUS with the Sonoprobe System in 85 cases of superficial esophageal carcinoma before treatment and evaluated the resected specimens histopathologically. We interpreted the depth of tumor invasion based on our fundamental studies of ultrasonograms taken with a 20-MHz probe.

RESULTS

The clinical usefulness of the Sonoprobe with linear and radial scanning modes is due to its capacity to differentiate between mucosal and submucosal carcinoma by means of analyses of the muscularis mucosae. Although a clear assessment of microinvasion and lymphoid hyperplasia surrounding the tumor of interest remains speculative, the diagnostic accuracy rate for 96 lesions of superficial esophageal carcinoma reached 93% in terms of differentiating between mucosal from submucosal carcinoma.

CONCLUSION

EUS with the Sonoprobe can play an important role in the pretreatment diagnosis of superficial esophageal carcinomas.

Subfascial endoscopic perforator surgery using a soft trocar for varicose veins in the lower leg

Objective: To describe the use of a novel soft trocar to perform subfascial endoscopic perforator surgery (SEPS) in patients with varicose veins in the lower leg.

Procedures: From January 1999 through March 2001, SEPS was performed in 14 patients (17 legs) with primary varicose veins (clinical classes 3-6) by using a soft trocar. The soft trocar is a Y-shaped polyvinyl chloride bag with two ports at one end and a flexible, sealing ring at the opposite end. The subfascial space was dissected with an endoscopic dissection cannula and expanded with a balloon. Carbon dioxide gas insufflation was applied, and the perforating veins were divided by using UltraShears inserted simultaneously with an endoscope through the second port of the trocar.

Results: A mean of 4.7 ± 2.9 perforating veins per leg were divided. No wound complications occurred.

Conclusion: Use of the soft trocar facilitates both visualization and manipulation during SEPS.

Atheroembolic signals detected by Doppler ultrasound scan monitoring in a patient with blue toe syndrome: report of a case

It is generally accepted that clinical symptoms give the only clue to the presence of atheroemboli in patients with blue toe syndrome (BTS). We report a case of atheroemboli originating from the abdominal aortic aneurysm in which Doppler ultrasound successfully detected atheroembolic signals, which vanished immediately after surgery. To our knowledge, this is the first such case to be documented. When a 67-year-old man was given warfarin after aortocoronay bypass, digital cyanosis suddenly developed, which became worse and was very painful. Angiography and computed tomography scanning revealed an infrarenal aortic aneurysm with mural thrombus. Doppler ultrasound detected atheroemboli as high-intensity transient signals in the bilateral tibioperoneal trunks. After aneurysmectomy and a bifurcated graft replacement, the cyanotic and painful toes improved immediately. Microscopically, cholesterin crystals were seen in the arterioles of the amputated digits. Thus, Doppler ultrasound could be a valuable test to determine the appropriate treatment for patients at risk of atheroembolic BTS.

IFN-gamma production from liver mononuclear cells of mice in burn injury as well as in postburn bacterial infection models and the therapeutic effect of IL-18

Hosts after severe burn injury are known to have a defect in the Th1 immune response and are susceptible to bacterial infections. We herein show that liver NK cells are potent IFN-gamma producers early after burn injury. However, when mice were injected with LPS 24 h after burn injury, IFN-gamma production from liver mononuclear cells (MNC; which we previously showed to be NK cells) was suppressed, and the serum IFN-gamma concentration did not increase, while serum IL-10 conversely increased compared with control mice. Interestingly, a single injection of IL-18 simultaneously with LPS greatly restored the serum IFN-gamma concentration in mice with burn injury and also increased IFN-gamma production from liver MNC. Nevertheless, a single IL-18 injection into mice simultaneously with LPS was no longer effective in the restoration of serum IFN-gamma and IFN-gamma production from the liver MNC at 7 days after burn injury, when mice were considered to be the most immunocompromised. However, IL-18 injections into mice on alternate days beginning 1 day after burn injury strongly up-regulated LPS-induced serum IFN-gamma levels and IFN-gamma production from liver and spleen MNC of mice 7 days after burn injury and down-regulated serum IL-10. Furthermore, similar IL-18 therapy up-regulated serum IFN-gamma levels in mice with experimental bacterial peritonitis 7 days after burn injury and greatly decreased mouse mortality. Thus, IL-18 therapy restores the Th1 response and may decrease the susceptibility to bacterial infection in mice with burn injury.

Doppler ultrasound monitoring for detection of microembolic signals in peripheral arteries

OBJECTIVE

to use Doppler ultrasound to detect peripheral microemboluation.

METHODS

standard Transcranial Doppler equipment was used to peripheral detect peripheral embolic high intensity transient signals (HITSs) in a pig model following injection of microparticles and atheroma, and in 23 patients who underwent open repair of an abdominal aortic aneurysm (AAA), six patients with blue toe syndrome and 10 age matched healthy subjects.

RESULTS

the pig study showed increasing signal intensity with particle size. Particles of 100 (n=24), 200 (n=17), and 400 microm (n=31) elicited 14, 25, 33 dB signals, respectively (p<0.05). During AAA surgery, the intensity (median) of HITSs before clamping (n=226) and after declamping (n=1216) were 14, and 20dB, respectively (p<0.001). Quite a few HITSs were detected after surgery. In patients with blue toe syndrome, a total of 63 HITSs could be detected, and the frequency of HITSs (median: 5.72/30min) was significantly higher than that in patients with AAA before surgery (0.065/30min) (p<0.001).

CONCLUSIONS

Doppler ultrasound technique may be a clinically useful test to guide the treatment of patients at risk of distal atheroembolic events.

The proximal form of mural thrombus in aortoiliac occlusive disease using computed tomography

BACKGROUND

It is important to know the nature of proximal thrombus in patients with aortoiliac occlusive disease (AIOD) when juxtarenal aortic clamping is scheduled. This study was aimed to evaluate the shape and nature of thrombi at several sites of the abdominal aorta in patients with AIOD using enhanced computed tomography (CT). Final judgment was made according to the operative findings.

METHODS

Between the years 1999 and 2001, 22 patients, who underwent aortobifemoral bypass, were enrolled. The shape and nature of their thrombi were examined at 4 points (superior mesenteric, suprarenal, juxtarenal and infrarenal arteries at the level of the 2 cm before the renal artery) and 88 slices of CT were examined retrospectively.

RESULTS

There was mural thrombus in 31 slices, which could be classified into 4 shapes (crescent-shaped: 10 cases; magatama: 2; wavy: 12; circular: 6). The wavy and circular shaped thrombi were found to be atheromatous. Nine cases (40.9%) on operative findings were atheroma (wavy: 4; circular shaped: 5). The crescent shape might correspond to fibrin thrombus. Atheromatous thrombus clamping near the renal artery was thought to cause microthromboembolism to surrounding organs.

CONCLUSIONS

It is recommended that the more proximal aorta or splanchnic arteries should be temporarily clamped during proximal procedures in patients with wavy or circular shaped thrombi at the juxtarenal aorta to prevent kidney or bowel infarction.