[Incisional hernias: epidemiology, evidence and guidelines]

BACKGROUND

From an epidemiological point of view, one third of the population in industrialized countries will undergo abdominal surgery during their lifetime. Depending on the degree of patient-related and procedure-related risks, the occurrence of incisional hernias is associated in a range of up to 30% at 2‑year follow-up and even up to 60% at 5 years. In addition to influencing comorbidities, the type of surgical approach and closure technique are of critical importance.

OBJECTIVE

To present a descriptive evidence-based recommendation for abdominal wall closure and prophylactic mesh augmentation.

MATERIAL AND METHODS

A concise summary was prepared incorporating the current literature and existing guidelines.

RESULTS

According to recent studies the recognized risk for the occurrence of incisional hernias in the presence of obesity and abdominal aortic diseases also applies to patients undergoing colorectal surgery and the presence of diastasis recti abdominis. Based on high-level published data, the short stitch technique for midline laparotomy in the elective setting has a high level of evidence to be a standard procedure. Patients with an increased risk profile should receive prophylactic mesh reinforcement, either onlay or sublay, in addition to the short stitch technique. In emergency laparotomy, the individual risk of infection with respect to the closure technique used must be included.

CONCLUSION

The avoidance of incisional hernias is primarily achieved by the minimally invasive access for laparoscopy. For closure of the most commonly used midline approach, the short stitch technique and, in the case of existing risk factors, additionally mesh augmentation are recommended.

Postoperative Analgesics Score as a Predictor of Chronic Postoperative Inguinal Pain After Inguinal Hernia Repair: Lessons Learned From a Retrospective Analysis

BACKGROUND

Chronic postoperative inguinal pain (CPIP) is a common complication after inguinal hernia surgery and occurs in up to 10-14% of cases. CPIP has a significant impact on daily life, work ability and thus compromises quality of life. The aim of this retrospective study was an in-depth analysis of patients undergoing inguinal hernia repair to further refine the prediction of the onset of CPIP reliably.

METHODS

A single center retrospective analysis of patients with who underwent open or minimally invasive inguinal hernia repair from 2016 to 2021 was carried out. Complication rates, detailed analysis of postoperative pain medication and quality of life using the EuraHS Quality of Life questionnaire were assessed.

RESULTS

Out of 596 consecutive procedures, 344 patients were included in detailed analyses. While patient cohorts were different in terms of age and co-morbidities, and the prevalence of CPIP was 12.2% without differences between the surgical procedures (Lichtenstein: 12.8%; TEP 10.9%; TAPP 13.5%). Postoperative pain was evaluated using a newly developed analgesic score. Patients who developed CPIP later had a significant higher consumption of analgesics at discharge (p = 0.016). As additional risk factors for CPIP younger patient age and postoperative complications were identified.

CONCLUSION

The prospective use of the analgesic score established here could be helpful to identify patients that are at risk to develop CPIP. These patients could benefit from a structured follow-up to allow early therapeutic intervention to prevent chronification and restore the quality of life.

Robotic inguinal hernia repair (rTAPP) – A series of 300 cases

Objective

While inguinal hernia repair using mesh is the recommended standard for most patients, minimal invasive techniques experienced a prolonged process until broad acceptance and sufficient expertise. Lately, a reluctance towards the integration of robotic hernia repair as a standard procedure is observed in Europe compared to the US. Nevertheless, robotic technology is a powerful tool for increasing quality in standardized procedures. We present a large case series of inguinal hernias repaired by robotic surgery.

Methods

All consecutive patients receiving a robotic inguinal hernia repair with a transabdominal approach (rTAPP) in the first 18 months (May 2018 up to October 2019) after introduction of the DaVinci Xi system at our institution were included in this study.

Results

Overall, 302 groin hernias in 225 patients were operated in the defined period. 77 patients presented with bilateral hernias. Mean age of patients was 58.7 years, 87.6% were men. Mean BMI 25.5kg/m2.

Nearly half of all operations were teaching operations making use of the available double consoles. While in the first 6 months only 20.0% of operations were teaching procedures, the rate increased to 60.3% in the last 6 months of the observation period.

While overall 35.6% of procedures were performed as day-surgery, the rate varied over the course of the study with 35.6% in the first 6 months, 46.0% in the second and 33.3% in the last 6 months.

Operation time was 82.6min. (range 40-186) with 72min. (range 40-186) for unilateral repairs and 101.3min. (range 52-169) for bilateral repairs. Further subgroup analysis showed that in bilateral repairs in primary hernias teaching vs. no-teaching operations differed only marginally in time (108.9min., range 66-149 vs. 91.6min., range 52-159).

Follow-up data was available for 93.8% of patients. There were no cases of recurrence; two patients experienced postoperative pain lasting more than 30 days. Seroma was observed in 8.9%, haematoma in 4.4% cases. Urinary retention occurred in 3.6% of patients, PE in 0.4%, DVT in 0.4%, epididymitis in 3.1%.

Conclusion

Robotic inguinal hernia repair is an outstanding and safe procedure. The operative accuracy of the system is impressive. The availability of two consoles makes it an ideal teaching tool, allowing to train residents in inguinal hernia repair, in a high standard of safety and with good outcomes.

The Open Abdomen Route by EuraHS: introduction of the data set and initial results of procedures and procedure-related complications

INTRODUCTION

Open abdomen management has become a well-established strategy in the treatment of serious intra-abdominal pathologies. Key objectives are fistula prevention and high fascial closure rates. The current level of evidence on laparostoma is insufficient. This is due to the rareness of laparostomas, the heterogeneity of study cohorts, and broad diversity of techniques. Collecting data in a standardised, multicentre registry is necessary to draw up evidence-based guidelines.

MATERIALS AND METHODS

In order to improve the level of evidence on laparostomy, CAMIN (surgical working group for military and emergency surgery) of DGAV (German Society for General and Visceral Surgery), initiated the implementation of a laparostomy registry. This registry was established as the Open Abdomen Route by EuraHS (European Registry of Abdominal Wall Hernias). Key objectives include collection of data, quality assurance, standardisation of therapeutic concepts and the development of guidelines. Since 1 May 2015, the registry is available as an online database called Open Abdomen Route of EuraHS (European Registry of Abdominal Wall Hernias). It includes 11 categories for data collection, including three scheduled follow-up examinations.

RESULTS

As part of this pilot study, all entries of the first 120 days were analysed, resulting in a review of 82 patients. At 44%, secondary peritonitis was the predominant indication. The mortality rate was 22%. A comparison of methods with and without fascial traction reveals fascial closure rates of 67% and 25%, respectively (intention-to-treat analysis, p < 0.03). Inert visceral protection was used in 67% of patients and achieved a small bowel fistula incidence of only 5.5%.

DISCUSSION

Optimising laparostomy management techniques in order to achieve low incidence of fistulation and high fascial closure rates is possible. The method that ensures the best possible outcome-based on current evidence-would involve fascial traction, visceral protection and negative pressure. The laparostomy registry is a useful tool for quickly generating sufficient evidence for open abdomen treatment.

Discovery of N-[4-(1H-Pyrazolo[3,4-b]pyrazin-6-yl)-phenyl]-sulfonamides as Highly Active and Selective SGK1 Inhibitors

From a virtual screening starting point, inhibitors of the serum and glucocorticoid regulated kinase 1 were developed through a combination of classical medicinal chemistry and library approaches. This resulted in highly active small molecules with nanomolar activity and a good overall in vitro and ADME profile. Furthermore, the compounds exhibited unusually high kinase and off-target selectivity due to their rigid structure.

Compound screening platform using human induced pluripotent stem cells to identify small molecules that promote chondrogenesis

Articular cartilage, which is mainly composed of collagen II, enables smooth skeletal movement. Degeneration of collagen II can be caused by various events, such as injury, but degeneration especially increases over the course of normal aging. Unfortunately, the body does not fully repair itself from this type of degeneration, resulting in impaired movement. Microfracture, an articular cartilage repair surgical technique, has been commonly used in the clinic to induce the repair of tissue at damage sites. Mesenchymal stem cells (MSC) have also been used as cell therapy to repair degenerated cartilage. However, the therapeutic outcomes of all these techniques vary in different patients depending on their age, health, lesion size and the extent of damage to the cartilage. The repairing tissues either form fibrocartilage or go into a hypertrophic stage, both of which do not reproduce the equivalent functionality of endogenous hyaline cartilage. One of the reasons for this is inefficient chondrogenesis by endogenous and exogenous MSC. Drugs that promote chondrogenesis could be used to induce self-repair of damaged cartilage as a non-invasive approach alone, or combined with other techniques to greatly assist the therapeutic outcomes. The recent development of human induced pluripotent stem cell (iPSCs), which are able to self-renew and differentiate into multiple cell types, provides a potentially valuable cell resource for drug screening in a "more relevant" cell type. Here we report a screening platform using human iPSCs in a multi-well plate format to identify compounds that could promote chondrogenesis.

Intracoronary local paclitaxel delivery by X-ray contrast media for in-stent restenosis: a clinical pilot study to assess safety and tolerability

AIM

Non-stent-based immediate release formulations of paclitaxel have been shown to reduce in-stent restenosis in animal experiments and clinical trials. In the porcine overstretch model paclitaxel dissolved in the contrast medium iopromide inhibited neointimal proliferation in a dose-dependent manner after intracoronary injection and was well tolerated.

METHODS

As a first step entering clinical development, a phase I trial was performed using four ascending paclitaxel dose/concentration levels: samples of up to 100 mL of the contrast medium (iopromide) containing 10, 50, 100 or 200 µM paclitaxel or iopromide (controls) were randomly administered to patients assigned to bare metal stent implantation for single de novo coronary artery lesions. Safety variables, tolerability and angiographic parameters were assessed.

RESULTS

Adverse events, ECG, systolic and diastolic blood pressure, left ventricular ejection fraction, leukocyte count, other hematological or clinical chemistry data did not reveal any trend which could be related to the study medication. Short-lasting serum paclitaxel concentrations remained significantly below those known from cancer therapy. Angiographic late lumen loss was 0.72±0.50 mm (N.=7) in controls versus 0.45±0.65 mm (N.=17) in all paclitaxel-treated patients; binary restenosis rate was 5/7(63%) versus 6/17 (35%) and target lesion revascularization rate was 4/8 (50%) versus 4/24 (17%).

CONCLUSION

Intracoronary infusion of paclitaxel dissolved in an X-ray contrast medium was well tolerated. The results show restenosis inhibition, but the number of patients examined was too small to demonstrate a statistically significant inhibition.

Wif-1 is expressed at cartilage-mesenchyme interfaces and impedes Wnt3a-mediated inhibition of chondrogenesis

Wnt factors are involved in the regulation of all steps of cartilage development. The activity of Wnt factors is generally regulated at the extracellular level by factors like the Dkk family, sFRPs, Cerberus and Wnt inhibitory factor 1 (Wif-1). Here we report that Wif-1 is highly expressed at cartilage-mesenchyme interfaces of the early developing skeleton. In fetal and postnatal skeletal development, Wif-1 is expressed in a sharply restricted zone in the upper hyaline layer of epiphyseal and articular cartilage and in trabecular bone. Coimmunoprecipitation and pull-down assays using recombinant Wif-1 and Wnt factors show specific binding of Wif-1 to Wnt3a, Wnt4, Wnt5a, Wnt7a, Wnt9a and Wnt11. Moreover, Wif-1 was able to block Wnt3a-mediated activation of the canonical Wnt signalling pathway. Consequently, Wif-1 impaired growth of mesenchymal precursor cells and neutralised Wnt3a-mediated inhibition of chondrogenesis in micromass cultures of embryonic chick limb-bud cells. These results identify Wif-1 as a novel extracellular Wnt modulator in cartilage biology.

Ucma, a novel secreted cartilage-specific protein with implications in osteogenesis

Here we report on the structure, expression, and function of a novel cartilage-specific gene coding for a 17-kDa small, highly charged, and secreted protein that we termed Ucma (unique cartilage matrix-associated protein). The protein is processed by a furin-like protease into an N-terminal peptide of 37 amino acids and a C-terminal fragment (Ucma-C) of 74 amino acids. Ucma is highly conserved between mouse, rat, human, dog, clawed frog, and zebrafish, but has no homology to other known proteins. Remarkable are 1-2 tyrosine sulfate residues/molecule and dense clusters of acidic and basic residues in the C-terminal part. In the developing mouse skeleton Ucma mRNA is expressed in resting chondrocytes in the distal and peripheral zones of epiphyseal and vertebral cartilage. Ucma is secreted into the extracellular matrix as an uncleaved precursor and shows the same restricted distribution pattern in cartilage as Ucma mRNA. In contrast, antibodies prepared against the processed C-terminal fragment located Ucma-C in the entire cartilage matrix, indicating that it either diffuses or is retained until chondrocytes reach hypertrophy. During differentiation of an MC615 chondrocyte subclone in vitro, Ucma expression parallels largely the expression of collagen II and decreases with maturation toward hypertrophic cells. Recombinant Ucma-C does not affect expression of chondrocyte-specific genes or proliferation of chondrocytes, but interferes with osteogenic differentiation of primary osteoblasts, mesenchymal stem cells, and MC3T3-E1 pre-osteoblasts. These findings suggest that Ucma may be involved in the negative control of osteogenic differentiation of osteochondrogenic precursor cells in peripheral zones of fetal cartilage and at the cartilage-bone interface.

Twisted Gastrulation Modulates Bone Morphogenetic Protein-induced Collagen II and X Expression in Chondrocytesin Vitroandin Vivo

Twisted gastrulation (TSG) is an extracellular modulator of bone morphogenetic protein (BMP) activity and regulates dorsoventral axis formation in early Drosophila and Xenopus development. Studies on tsg-deficient mice also indicated a role of this protein in skeletal growth, but the mechanism of TSG activity in this process has not yet been investigated. Here we show for the first time by in situ hybridization and immunohistochemistry that TSG is strongly expressed in bovine and mouse growth plate cartilage as well as in fetal ribs, vertebral cartilage, and cartilage anlagen of the skull. Furthermore we provide evidence that TSG is directly involved in BMP-regulated chondrocyte differentiation and maturation. In vitro, TSG impaired the dose-dependent BMP-2 stimulation of collagen II and X expression in cultures of MC615 chondrocytes and primary mouse chondrocytes. In the presence of chordin, a BMP antagonist, the inhibitory effect of TSG was further enhanced. TSG also inhibited BMP-2-stimulated phosphorylation of Smad factors in chondrocytes, confirming the role of TSG as a modulator of BMP signaling. For analysis of TSG functions in cartilage development in vivo, the gene was overexpressed in transgenic mice under the control of the cartilage-specific Col2a1 promoter. As a result, Col10a1 expression was significantly reduced in the growth plates of transgenic embryos and newborns in comparison with wild type littermates as shown by in situ hybridization and by real time PCR analysis. The data suggest that TSG is an important modulator of BMP-regulated cartilage development and chondrocyte differentiation.

Shortening the stent length reduces restenosis with bare metal stents: matched pair comparison of short stenting and conventional stenting

OBJECTIVE

To investigate the effect of reducing stent length on the rate of target lesion restenosis.

DESIGN

In a prospective investigation, acute and long term results of a short stenting procedure were analysed by quantitative angiography and compared with results of a conventional stenting procedure selected according to a matched pairs analysis.

PATIENTS

Short stents were implanted in 400 consecutive patients with 464 lesions and conventional stents in 430 patients. Demographic and lesion characteristics were comparable between groups.

INTERVENTIONS

In short stenting, the shortest stent length to cover only segments with > 30% reduction in vessel diameter was used. In conventional stenting, full coverage of a stenotic vessel segment was intended.

MAIN OUTCOME MEASURES

The mean stent lengths of the short stent group (9.8 (4) mm) and the conventional stent group (16.3 (7) mm) differed significantly (p < 0.0001); all other procedural and angiographic parameters were the same. Procedural success was similar for both groups. Control angiography after six months was conducted in 92% of patients.

RESULTS

Short stenting resulted in both less restenosis (68 of 431 (15.8%)) than conventional stenting (93 of 381 (24.4%), p = 0.007) and less late lumen loss (0.6 (0.6) mm v 0.75 (0.5) mm, p = 0.0001). Residual stenosis (< 45%) in adjacent vessel segments after short stenting did not affect the restenosis rate. Only the implantation of a < or = 9 mm stent predicted the absence of restenosis in a multivariate analysis.

CONCLUSION

Shortening the length of bare metal stents reduces the restenosis rate as compared with conventional stenting.

Repression of anti-proliferative factor Tob1 in osteoarthritic cartilage

Osteoarthritis is the most common degenerative disorder of the modern world. However, many basic cellular features and molecular processes of the disease are poorly understood. In the present study we used oligonucleotide-based microarray analysis of genes of known or assumed relevance to the cellular phenotype to screen for relevant differences in gene expression between normal and osteoarthritic chondrocytes. Custom made oligonucleotide DNA arrays were used to screen for differentially expressed genes in normal (n = 9) and osteoarthritic (n = 10) cartilage samples. Real-time polymerase chain reaction (PCR) with gene-specific primers was used for quantification. Primary human adult articular chondrocytes and chondrosarcoma cell line HCS-2/8 were used to study changes in gene expression levels after stimulation with interleukin-1β and bone morphogenetic protein, as well as the dependence on cell differentiation. In situ hybridization with a gene-specific probe was applied to detect mRNA expression levels in fetal growth plate cartilage. Overall, more than 200 significantly regulated genes were detected between normal and osteoarthritic cartilage (P < 0.01). One of the significantly repressed genes, Tob1, encodes a protein belonging to a family involved in silencing cells in terms of proliferation and functional activity. The repression of Tob1 was confirmed by quantitative PCR and correlated to markers of chondrocyte activity and proliferation in vivo. Tob1 expression was also detected at a decreased level in isolated chondrocytes and in the chondrosarcoma cell line HCS-2/8. Again, in these cells it was negatively correlated with proliferative activity and positively with cellular differentiation. Altogether, the downregulation of the expression of Tob1 in osteoarthritic chondrocytes might be an important aspect of the cellular processes taking place during osteoarthritic cartilage degeneration. Activation, the reinitiation of proliferative activity and the loss of a stable phenotype are three major changes in osteoarthritic chondrocytes that are highly significantly correlated with the repression of Tob1 expression.

[Investigation of diabetic men with erectile dysfunction to determine coronary flow reserve (CFR) and cardiac risk under medication with sildenafil (Viagra)]

PURPOSE

Since Sildenafil (Viagra) has become available, there have been reports of death and cardiac risks associated with its use. As large doses of Sildenafil medication is often prescribed particularly in diabetic patients with erectile dysfunction (ED), our study was designed to evaluate the coronary flow reserve (CFR) and possible resulting cardiac risk specifically in diabetic men.

MATERIALS AND METHODS

Because these men often suffer from clinically significant ischaemic heart problems without their knowledge and without symptoms, all of our patients were examined by treadmill ECG and CFR.

RESULTS

In 44 men (35 - 74 years) with type I and II diabetes also suffering from ED objectified by FCDS measurement of the penile vessels, a surprisingly high rate of objective cardiac problems were found, which were then verified by coronary angiography. These patients are at risk for ischaemic problems during Sildenafil-assisted intercourse and were excluded from further study. Interestingly, only 3 of theses 11 men would have been detected by conventional examinations. Patients free of coronary stenosis who received 50 mg Sildenafil (20 patients) showed no cardiac problems during treadmill exercise and CFR measurement.

CONCLUSIONS

Coronary flow reserve in diabetic men lies at the lower end of the normal range, but is not further decreased by Sildenafil. However, diabetics with ED frequently showed coronary artery stenosis that was not clinically symptomatic. Furthermore, conventional cardiological examinations often fail to detect these patients, although they are at ischaemic risk during medically assisted intercourse. Furthermore, although 5 of 20 men who received Sildenafil had an increase in penile blood flow without sexual stimulation, only 7 of 20 were responders to Sildenafil after take home medication. Thus, Sildenafil medication is not a suitable test medication for organic erectile dysfunction.

[Clinical application--suture materials]

The surgical suture should be chosen in dependence of the tissue being operated upon and be oriented on the main properties of its chemical composition. Synthetic absorbable suture materials are the first choice in the majority of the procedures, to prevent the formation of foreign body reaction--excepting sites subjected to continuous mechanical stress, for example hernias, orthopedic and vascular surgery. By causing lesser tissue damage and interfilament bacterial transport, monofilament sutures are preferable than multifilament ones. However, knotting monofilament sutures requires additional skills in comparison to multifilament strains, due to their special handling an knotting properties.

[Sildenafil does not change coronary flow reserve in diabetics with erectile dysfunction]

BACKGROUND AND AIM OF STUDY

Disturbance of the microvascular coronary circuit is common in diabetics with erectile dysfunction. We investigated effects of sildenafil on coronary flow reserve (CFR) of the left anterior descending branch.

PATIENTS AND METHODS

43 diabetics (aged 59 +/- 7 years) with erectile dysfunction and without symptoms of coronary artery disease were selected. Cardiac diagnosis, including stress ECG and echocardiography was performed in all. Because of the clinical suspicion of coronary artery disease coronary angiography was performed in 16 of them. Severe coronary artery disease was confirmed in 12 patients who were excluded from further analyses as well as 10 diabetics in whom coronary flow measurements were not possible. In the other 21 diabetics, adenosine-mediated CFR was calculated at baseline and 1 hour after ingestion of 50 mg sildenafil by transthoracic Doppler echocardiography.

RESULTS

CFR at baseline was at the lower level of the normal range in 17/21 diabetics (median 245 %, range 210 - 490 %). CFR decreased insignificantly in 12/21 patients after sildenafil administration (Delta CFR -10 %, p = 0.3). Patients with a body mass index > 25 kg/m(2), and left ventricular hypertrophy had the highest reduction of CFR after sildenafil, but a drop of the CFR below 200 % was not observed in any patient. Systemic blood pressure dropped significantly from 130/80 mmHg to 120/72 mmHg (p < 0.002).

CONCLUSION

Diabetics with erectile dysfunction often have a CFR in the lower range of normal. Sildenafil did not further reduce CFR. Asymptomatic, severe coronary artery disease often can be found in diabetics with erectile dysfunction. Cardiological screening for contraindications for sildenafil seems mandatory in diabetics with a high cardiovascular risk profile.

[Percutaneous revascularization of multivessel coronary disease using stents - a multicenter, prospective study]

BACKGROUND AND OBJECTIVE

Symptomatic patients with multivessel coronary disease (MVD) benefit from both coronary artery bypass grafting (CABG) and percutaneous coronary angioplasty (PTCA). The >>German Angioplasty Bypass Investigation<< (GABI-I) trial randomized patients to one of these treatment strategies between 1986 and 1991. In order to evaluate the impact of current technology, in particular coronary stents, the GABI-II trial was initiated, which in 1996 and 1997 prospectively enrolled patients according to the initial GABI-I criteria.

PATIENTS AND METHODS

Into the study 136 consecutive patients (108 men, 28 women; 63 +/- 12 years) were included. Patients from GABI-I served as controls.

RESULTS

A mean of 2.1 +/- 0.5 vessels were treated per patient (vs. 1.9 +/- 0.5 vessels in the PTCA arm of GABI-I) and 63 % of the lesions were covered with stents. With respect to the primary endpoint less patients remained with a CCS class III or IV in GABI-II after 12 months (1,5 % vs. 8 % in the PTCA arm of GABI-I, p<0,01). No patient required emergency or urgent bypass operation in GABI-II (vs. 9 % in GABI-I, p < 0.01). After 12 months, 8 % of the patients were sent for bypass surgery (CABG) vs. 21 % in GABI-I (p < 0.001), and 20 % (vs. 23 % in GABI-I) of the patients underwent Re-PTCA. The percentage of patients without reinterventions was 72 % vs. 56 % in GABI-I (p < 0.01), but remained lower compared to patients randomized to CABG in GABI-I (94 %, p < 0.001).

CONCLUSION

PTCA in patients with MVD is still associated with a higher reintervention rate as compared with CABG. However, in contrast to angioplasty a decade ago, PTCA in conjunction with stents significantly lowered the need for subsequent revascularization, which was mainly driven by the reduced necessity for bypass surgery.

Angiographic analysis of immediate and long-term results of PTCR vs. PTCA in complex lesions (COBRA study)

We conducted a prospective, randomized trial to compare immediate and long-term effects of percutaneous transluminal coronary angioplasty (PTCA) and high-frequency rotational atherectomy (PTCR) in patients with angiographically predefined complex coronary artery lesions (AHA type B2 and C). The relation of lesion characteristics to procedural results is reported in this angiographic analysis. Patients were randomly assigned to balloon angioplasty (n = 250 patients) or rotational atherectomy (n = 252 patients). Quantitative coronary angiography could be performed in 447 patients to evaluate immediate results and in 293 patients with a 6-month angiographic follow-up. Procedural success was comparable in the PTCR and in the PTCA group (80% vs. 76%, P = 0.260). The need for stent implantation due to a residual stenosis >50% or a bail-out situation was significantly higher in the PTCA group (9.7% vs. 2.0%, P = 0.001). In both treatment groups, diameter stenosis was effectively reduced and MLD increased. The acute gain did not differ between the two groups. At 6-month control, the restenosis rate was comparable in the PTCR and in the PTCA group (37% vs. 35%, P = 0.658), whereas diameter stenosis was significantly more severe in the PTCR group than in the PTCA group (52% vs. 46%, P = 0.039) and, correspondingly, the MLD was significantly smaller in the PTCR group (1.29 mm vs. 1.44 mm, P = 0.031). Late loss was about the same in both groups, however, net gain and net gain index were significantly higher in the PTCA group (0.82 mm vs. 0.64 mm, P = 0.008; and 31% vs. 24%, P = 0.009). Analysis of procedural results for various lesion characteristics revealed no significant difference between treatment groups. In this randomized trial, complex coronary artery lesions were treated with comparable results for angiographic and procedural success and the restenosis rate by both, PTCA and PTCR. Late loss, however, was significantly higher and net gain significantly smaller after PTCR. Stents, although infrequently used, had a relevant impact on immediate PTCA results but not on late results. Cathet Cardiovasc Intervent 2001;53:359-367.

Temperature-controlled high frequency ablation for creation of transmyocardial channels: in vivo validation of a novel method

OBJECTIVE

We investigated the feasibility and short-term effects of a novel procedure to create intramyocardial channels by means of high frequency (HF) ablation in a rabbit in vivo model.

METHODS

A flexible catheter ending in a cylindrical electrode (diameter 0.7 mm) with a sharpened tip was used for HF energy application following transmyocardial insertion. Power-controlled or energy-controlled energy applications were performed in 16 anesthetized rabbits after thoracotomy with a follow-up for 3 h. Assessment of myocardial channels and the necrotic zone was performed by morphometric quantification in serial sections. The ferret diameter was used to compare channel dimensions and the extent of necrosis.

RESULTS

Thirty-nine power-controlled and 54 temperature-controlled HF applications were performed. The shape of identified channels was round in 71% and 69% had a lumen patency of > or =2/3 of the channel. Ferret diameter of the channels was 414 +/- 180 microm and of the necrotic zone 3,558 +/- 1,200 microm. In temperature-controlled applications, channel dimensions were strongly influenced by the maximum tissue temperature and the duration of energy delivery (T(max): p = 0.0006; duration: p = 0. 003). Channel and necrosis dimensions correlated better with biometric parameters in temperature-controlled compared with power-controlled applications.

CONCLUSION

Mechanically created transmyocardial channels can be stabilized by HF heating of the surrounding tissue. A high percentage of these channels remain patent. The channel dimensions are closely correlated with maximum temperature and duration of energy delivery in a temperature-controlled application mode.

A randomized comparison of balloon angioplasty versus rotational atherectomy in complex coronary lesions (COBRA study)

AIMS

Rotablation is a widely used technique for the treatment of complex coronary artery lesions but is so far only poorly supported by controlled studies. The Comparison of Balloon-Angioplasty versus Rotational Atherectomy study (COBRA) is a multicentre, prospective, randomized trial to compare short- and long-term effects of percutaneous transluminal coronary angioplasty (PTCA) and rotablation in patients with angiographically pre-defined complex coronary artery lesions.

METHODS AND RESULTS

At seven clinical sites 502 patients with pre-defined complex coronary artery lesions were assigned to either PTCA (n=250) or rotablation (n=252). Primary end-points were procedural success, 6-month restenosis rates in the treated segments, and major cardiac events during follow-up. Procedural success was achieved in 78% (PTCA), and 85% (rotablation) (P=0.038) of cases. Crossover from PTCA to rotablation was 4% and 10% vice versa (P=0.019). There was no difference between PTCA and rotablation with respect to procedure-related complications such as Q wave infarctions (2.4% each), emergency bypass surgery (1.2% versus 2.4%), and death (1.6% versus 0.4%). However, more stents were required after PTCA (14.9% versus 6.4%, P<0.002), predominantly for bailout or unsatisfactory results. Including bail-out stents as an end-point, the procedural success rates were 73% for angioplasty and 84% for rotablation (P=0.006). At 6 months, symptomatic outcome, target vessel reinterventions and restenosis rates (PTCA 51% versus rotablation 49%, P=0.33) were not different.

CONCLUSION

Complex coronary artery lesions can be treated with a high level of success and low complication rates either by PTCA with adjunctive stenting or rotablation. The long-term clinical and angiographic outcome is comparable.

Impact of routine angiographic follow-up after angioplasty

BACKGROUND

There is an ongoing controversy as to whether repeat coronary angiography should be routinely performed after successful percutaneous transluminal coronary angioplasty (PTCA).

METHODS

We examined the 10-year outcome in 400 patients who had or had not undergone an angiographic control 6 months after successful PTCA and a subsequent event-free 6-month period. Our comparison was based on data gathered by questionnaire and telephone interview in 315 patients with (group A) and 85 patients without (group B) a routine 6-month angiographic control. Multivariate analysis (Cox model) was performed to identify predictors of adverse events.

RESULTS

During the 10-year follow-up period, 22 (7%) of the 315 patients in group A died, compared with 16 (19%) patients in group B (P= .003). In groups A and B, respectively, acute myocardial infarction occurred in 28 (9%) and 10 (12%) patients (not significant [NS]); coronary artery bypass grafting (CABG) was performed in 42 (13%) and 14 (16%) patients (NS); repeat PTCA was performed in 89 (28%) and 11 (13%) patients (P= .012); and serious adverse events (death, myocardial infarction, CABG) occurred in 76 (24%) and 32 (38%) patients (P= .02). Absence of a 6-month angiographic follow-up was identified as an independent predictor of death associated with a 2.7 times higher mortality rate during the 10-year follow-up period. Previous myocardial infarction increased the risk of death 2.5 times. Any increase of residual diameter stenosis by 10% was combined with a 1.4 times higher mortality rate. The chance of bypass surgery was higher in patients with multivessel disease (2.9 times), in patients with unstable angina (2.1 times), and in case of an increase of residual diameter stenosis by 10% (1.3 times). No predictor for the risk of myocardial infarction was found. Angiographic follow-up increased the likelihood of PTCA 2.5 times.

CONCLUSIONS

A routinely performed angiographic control 6 months after successful PTCA is associated with a significantly higher rate of repeat PTCA but, most important, is correlated with a significantly lower mortality rate during the 10-year follow-up period.

[Dynamic 31-phosphorus magnetic resonance spectroscopy of the m. quadriceps: therapy-induced changes in arterial occlusive disease]

PURPOSE

The present investigation aimed at examining changes in muscle metabolism caused by treatment of arterial occlusive disease, using dynamic 31-phosphorus methods.

METHOD

32 patients with arterial occlusive disease were examined in a 1.5 T apparatus with a 6 cm surface coil before and after treatment. The metabolic changes in the quadriceps muscles were visualised during a 36 s phosphorus spectrum during rest, exercise (isometric and isotonic) and during a period of recovery.

RESULTS

Vascular therapy resulted in a significant increase in the duration of both types of exercise during dynamic phosphorus spectroscopy (isometric exercise: 282 s against 199 s: p = 0.002, isotonic exercise: 575 s against 222 s; p = 5 x 10(-6). After treatment, exercise-induced changes in pH (7.00 against 6.94; p = 0.004 and 7.00 against 6.93; p = 0.02) and the ratio Pi/PCr (0.34 against 0.44; p = 0.002 and 0.36 against 0.50; p = 0.009) were significantly smaller than before therapy, using a similar amount of exercise. Recovery time of Pi/PCr (45 s against 82 s; P = 10(-5) and 42 s against 57 s; p = 0.01) and pH value (154 s against 181 s; p = 0.14 and 173 s against 214 s; p = 0.22) showed significant reduction after treatment.

CONCLUSIONS

Dynamic 31-phosphorus magnetic resonance spectroscopy indicates increased mitochondrial oxidative capacity in the quadriceps muscles as evidence for increased oxygen supply to muscle tissue following vascular therapy.

Comparison of QCA systems

AIMS

Excellent agreement between different 'second generation' systems for quantitative coronary arteriography (QCA) has been found in in vitro measurements. To verify the quality and stability of QCA when used in clinical practice, three QCA systems (AWOS, Cardio, and CMS) were used in a representative set of coronary artery lesions.

METHODS AND RESULTS

This set consisted of angiographic stenosis images of 57 patients which varied in stenosis severity and morphology. The process of image acquisition, calibration, and measurement was strictly standardized to eliminate procedural sources of error. Three observers performed QCA five times in each lesion with each QCA system. Interobserver variability was low (Dnorm 0.01-0.05 mm, Dmin 0.01-0.02 mm, %stenosis 0.3-0.7%). Values of system precision were excellent (Dnorm 0.11-0.13 mm, Dmin 0.04-0.06 mm, %stenosis 2.1-2.6%). Comparison of measurements between three QCA systems revealed good agreement (range of mean differences for Dnorm 0.03-0.12 mm, Dmin 0.04-0.11 mm, and %stenosis 0.5-3.6%) and high correlation (corr 0.902-0.977). There was a tendency to measure smaller values for Dmin and consequently to identify more severe stenoses with the AWOS system than with the Cardio and CMS systems. All QCA results were compared to measurements done with the Brown Dodge method to reveal failure of the QCA measurements. These results showed excellent agreement without any systematic deviation (mean differences for Dnorm 0.01-0.08 mm, Dmin 0.02-0.06 mm, and %stenosis 1.3-1.8%). None of the differences were statistically significant.

CONCLUSION

We therefore conclude that using the defined version of the AWOS, Cardio, and CMS systems, there is no difference in precision or accuracy when used for QCA of coronary artery lesions.

[Effect of qualitative stenosis characteristics on the quality of measurements of various QCA systems]

Reproducibility and accuracy of in vitro measurements are very high using recently developed QCA systems. We analyzed the impact of lesion characteristics ad the image quality on the quality of measurements under clinical conditions. For the study we selected 57 coronary artery lesions which had a clinically relevant distribution for stenosis severity, lesion characteristics, and image quality. Every effort was made to eliminate procedural sources of error. Three investigators measured each lesion five times with each of three QCA systems (AWOS, Cardio and CMS). Only the measurements of the minimal stenosis diameter were analyzed. The precision of all the measurements was high with the AWOS (0.04 mm), the Cardio (0.05 mm), and the CMS systems (0.06 mm). Variability of measurements increased for the following criteria: Ambrose-III morphology (CMS 0.082 mm), surface irregularities (Cardio 0.069 mm, CMS 0.073 mm), TIMI I (Cardio 0.084 mm, CMS 0.0121 mm), and moderate image quality (CMS 0.07 mm). There were no differences in the precision of the measurements in the other groups of lesion characteristics. There were no relevant differences in any of the measurements between the systems (AWOS-Cardio -0.07 mm, AWOS-CMS-0.11 mm, Cardio-CMS-0.04 mm). Smaller diameters were measured with the AWOS system than with the CMS and the Cardio systems when the lesion was calcified (AWOS-Cardio-0.109 mm, AWOS-CMS-0.161 mm). This was only a trend, however, and did not reach statistical significance, which was also true for the other differences found between the systems according to various lesion characteristics. In summary, we found that the measurement quality of the QCA systems used in this study is not altered by the underlying lesion characteristics or the image quality.

[Three-dimensional computer reconstruction of the pelvic and hip area in the preoperative planning of orthopedic interventions and surgical simulation]

RESEARCH QUESTION

Osteotomies are elective operations which require exact pre-operative planing. Computer assisted three-dimensional planning of orthopedic procedures requires a three-dimensional reconstruction of the region of interest. To be applicable, such a three-dimensional reconstruction must be an accurate mathematical description of the region of interest, and not only a 3-D-image. The purpose of this study was to create such an accurate 3-D reconstruction.

METHODS

We describe a method to create an exact reconstruction from CT-data, from the data acquisition, contour determination by an algorithm, triangulation of the resulting data and reconstruction of the region of interest.

CONCLUSION

The described method is a useful tool to obtain exact individual three-dimensional reconstructions of any skeletal region of interest. This makes pre-operative planning and simulation of the results of orthopedic procedures at the computer possible.

[Automatic report documentation in cardiology using a speech recognition system]

Computer systems that can convert spoken text into written text have recently become available. In one such system, the phonetics of spoken words are compared with those of 32 000 stored words, with a statistical program helping to choose the word with the highest probability of being correct. We evaluated the practicability of the IBM Voice Type system for writing medical reports using a cardiologic vocabulary. A total of 200 medical documents were generated with a mean of 301 +/- 52 words. In the mean, 12 +/- 5 words were falsely recognized in each document, resulting in a rate of correct recognition of 95.1 +/- 2.5%. It is possible to correct a falsely recognized word by choosing an alternative word from a provided list, which worked in our case in 51% (6.1 +/- 2.8 words in each document). Correction of falsely recognized words had to be done by manual input 49% of the time (5.9 +/- 2.9 words in each document). The mean time demand for word correction amounted to 57 +/- 15 s for each document, whereas correction by manual input needed more time (37 +/- 14 s) than choosing from a list of alternative words (20 +/- 4s). A requirement for use of the Voice Type system is a reduced speech rate. Dictation of our documents took on average 260 s when done with a normal speech rate, and 400 s when done at a reduced speech rate. In conclusion, automatic writing of cardiologic reports can be done easily and with a low failure rate using the IBM Voice Type system with a cardiologic vocabulary. It takes about 3 min longer to create a medical text 1 1/2 pages long which is free of mistakes by using the Voice Type system than to simply dictate the text. Time can be saved by eliminating the need to check a preliminary report. The major advantage of automated reporting is that the written report is immediately available. For each discipline, specific vocabularies should be validated.

Angiographic follow-up results of a randomized study on angioplasty versus bypass surgery (GABI trial). GABI Study Group

Although several randomized trials have been performed to compare the outcomes of percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass surgery (CABG) in patients with multivessel disease, there is little data available on angiographic follow-up results. The present substudy of the German angioplasty versus bypass surgery investigation (GABI Trial) compares the angiographic revascularization status in these two cases 6 months after treatment. Follow-up angiograms were available in 102 CABG patients and 117 PTCA patients. Although the protocol excluded patients with total occlusion, on follow-up 6 months after treatment we found total occlusion of 94 native arteries (36.9%) in the CABG group and of six arteries (2.5%) in the PTCA group (P < 0.001). The rate of occluded native vessels did not correlate significantly with the severity of the lesion before bypass surgery. In the CABG group 31 bypass grafts (12.2%) were found to be occluded at the 6 month follow-up examination (29/225 vein grafts [12.9%]; 2/30 mammary artery grafts [6.7%]). The main pathway, defined as the nutrient vessel (native vessel or bypass graft) providing the least resistance to blood flow, was narrowed by a lesion with a diameter stenosis of 70-100% for 36 target lesions (14.1%) in the CABG group and 39 target lesions (16.2%) in the PTCA group (P, ns). However, the prevalence of moderately severe lesions with a 50-69% diameter reduction of the main pathway was significantly greater in the PTCA group (44 lesions, 18.3%) than in the CABG group (19 lesions, 7.5%, P < 0.01). Thus, 6 months after randomized allocation to PTCA or CABG, we found comparable rates of high-grade lesions in the main pathways of both treatment groups. Whereas moderately severe lesions of the main pathway were predominantly seen in the PTCA group, there was marked disease progression to total occlusion in the native circulation after bypass grafting.

Differential expression of collagen types I, II, III, and X in human osteophytes

BACKGROUND

Osteophytes are neoplastic cartilaginous and osseous protrusions growing at the margins of osteoarthritic joints. Their formation involves complex patterns of cellular proliferation, differentiation, as well as matrix synthesis and turnover that are poorly understood.

EXPERIMENTAL DESIGN

Here we report on an experimental approach using in situ hybridization and immunohistology to elucidate pathways of chrondrocyte differentiation in human osteophytes. Ab and cDNA probes for collagen types were used as specific parameters for chondrocyte phenotypes.

RESULTS

In early precartilaginous mesenchymal tissue, cytoplasmic mRNA for alpha 1(I) and alpha 1(III) collagen genes (Col1A1 and Col3A1) were found by in situ hybridization, correlating with the distribution of type I and III collagen as revealed by Ab staining. Strong expression of type II collagen both at mRNA and protein levels was the hallmark of chondrogenic differentiation in the cartilaginous zone of osteophytes. Type II collagen expression increased in all cartilaginous and fibrocartilaginous areas with growth and maturation of osteophytes. The signal intensity obtained after in situ hybridization with a COL2A1 probe was high and corresponded to that obtained in fetal cartilage, whereas normal adult articular cartilage usually did not show measurable type II collagen expression. In fibrocartilaginous areas, the most abundant, but heterogeneous tissue type seen in osteophytes, type II and III collagen mRNA expression overlapped considerably. Type III collagen was scattered, both pericellularly and interterritorially, over the whole osteophyte, excluding bone and chondrocytic cells of the deep zone. The strongest type I collagen expression was seen in bone and in the superficial fibrous layer. In areas of endochondral ossification, large chondrocytes were found expressing type X collagen, a specific marker for hypertrophic chondrocytes.

CONCLUSIONS

These results show that discrete stages of cartilage differentiation can be precisely followed in osteophytes using collagen type-specific cDNA probes and Ab as markers. In addition, a fibrocartilaginous chondrocyte phenotype was identified that expresses type II and III, but not type I collagen.

High-frequency rotational ablation following failed percutaneous transluminal coronary angioplasty

Percutaneous transluminal coronary angioplasty (PTCA) failed in 29 of 1,150 patients (2.5%) after successful passage of the guide wire. The reasons for failure were inability to pass the lesion with a balloon in 28 patients and inability to dilate the lesion in 1 patient. In these patients (15 stenoses and 14 chronic occlusions) rotational ablation was performed. We were able to pass the burr through the lesion in all of them, resulting in a reduction of diameter stenosis from 87 +/- 15 to 51 +/- 18%. Rotational ablation alone was initially successful (stenoses reduction > 20% and residual stenoses < 50%) in 15 of 29 (52%) patients. Additional PTCA was performed in 21 of 29 (72%) patients, in 8 to optimize the initially successful result and in 13 because the outcome was unsatisfactory. After dilatation the diameter stenosis was reduced to 41 +/- 14% immediately after the procedure and to 36 +/- 13% at 24 hr control. Overall success was achieved in 21 of 29 (72%) patients immediately after the procedure and in 26 of 29 (90%) patients at 24 hr control. No acute major complications occurred. We conclude that rotational ablation can be used as a safe and effective alternative when PTCA is not successful.

High frequency rotational ablation: an alternative in treating coronary artery stenoses and occlusions

OBJECTIVE

To prove the safety and effectiveness of high frequency rotational ablation of coronary artery stenoses and occlusion in humans.

SUBJECTS

106 patients with symptoms (91 men, 15 women) who had 67 significant stenoses, mainly types B and C, and 46-chronic occlusions.

MAIN OUTCOME MEASURES

Mean change in diameter stenosis after rotational angioplasty alone and in combination with percutaneous transluminal coronary angioplasty immediately after treatment and 24 hours and six months later; restenosis rates at six months; complication of treatment.

RESULTS

Rotational ablation could not be used in five stenoses and 16 chronic occlusions because of inability to reach or cross the lesion with the Rotablator guide wire. In four cases rotational ablation failed. Initial angiographic and clinical success by rotational ablation was achieved in 40 of the 67 stenoses (60%) and in 18 of the 46 chronic occlusions (39%). Additional balloon angioplasty was performed in 45 patients, increasing the success rates to 79% and 54%, respectively. In the 62 stenoses treated by rotational ablation the angiographic diameter stenoses were reduced from 76% (SD 14%) to 32% (14%) after Rotablator treatment alone and from 75% (11%) to 33% (17%) with additional balloon angioplasty. In the 30 chronic occlusions treated by rotational ablation the angiographic diameter stenoses were reduced to 38% (18%). At six months angiographic restenosis was evident in nine of the 25 (36%) stenoses treated with rotational ablation alone, in seven of the 22 (32%) stenoses treated with rotational and balloon angioplasty, and in 14 of the 24 (58%) chronic occlusions. There were no procedural deaths and two patients (2%) underwent emergency coronary artery bypass grafting. Although no transmural infarction occurred, there were five (6%) non-Q wave infarctions (two embolic side branch occlusions, two subacute occlusions, and one acute occlusion). Clinically insignificant slight increases in creatine kinase activity were seen in five patients (6%). Severe coronary artery spasm unresponsive to medical treatment was provoked in seven cases (8%).

CONCLUSIONS

High frequency rotational ablation is a safe and effective method for treating type B and C coronary artery lesions with results comparable to percutaneous transluminal coronary balloon angioplasty. The combined use of rotational ablation and balloon angioplasty is feasible and is necessary in about half of all procedures, in most cases because the lumen created by the biggest burr is too small.

Alterations of collagen mRNA expression during retinoic acid induced chondrocyte modulation: absence of untranslated alpha 1(I) mRNA in hyaline chondrocytes

Retinoic acid (RA) has been shown to rapidly modulate the collagen expression pattern of chondrocytes in vitro at doses of 1-10 microM. Embryonic chicken sternal chondrocytes stop synthesizing the cartilage-specific type II collagen within 2-4 days of RA treatment and turn on the synthesis of types I and III collagen and fibronectin. While suppression of type II collagen synthesis and onset of type III collagen and fibronectin synthesis have been shown to be regulated at the transcriptional level, conflicting data are available on a possible post-translational regulation of alpha 1(I) collagen gene expression. In this study we demonstrate by comparing a commonly used alpha 1(I) cDNA probe from the 3' end of the alpha 1(I) mRNA with a newly prepared alpha 1(I) cDNA probe from the 5' end (p1E1) that--in contrast to previous reports--chicken sternal chondrocytes do not contain untranslated alpha 1(I) mRNA which may become translatable after RA treatment. By in situ hybridization we show the absence of cytoplasmic alpha 1(I) mRNA from chondrocytes and its presence in the perichondrium of sternal cartilage. Perichondral cells might have contaminated sternal chondrocyte preparations, explaining low levels of alpha 1(I) mRNA seen by Northern hybridization and RNase protection assays of chicken sternal cartilage mRNA even with the p1E1 probe. We show by Northern hybridization and metabolic labeling with 3H-proline followed by SDS-gel electrophoresis that retinoic acid at 3 microM suppresses type II, IX, and X collagen gene expression within 2 days both at the mRNA and protein level and induces the onset of alpha 1(I), alpha 2(I), and alpha 1(III) expression within 3 days. No expression of CRABP, the cellular retinoic acid binding protein, was seen in RA-treated or control chondrocytes, indicating that CRABP protein is not involved in the RA-induced modulation of the chondrocytes.

Influence of perinatal risk factors on the involution of the irido-pupillary membrane

The aim of this study was to assess the influence of common perinatal risk factors on the disappearance of the anterior vascular capsule of the lens (AVCL). Direct ophthalmologic examinations were performed on 75 neonates (27 to 35 weeks gestational age) in the first 24 hours after birth, using the degree of involution of the AVCL to estimate gestational age in high risk pregnancy. Our results show that the gradual disappearance of the AVCL is not influenced by perinatal risk factors, such as maternal preeclampsia, prenatal administration of steroids, neonatal infection and low birth weight, confirming the clinical value of this test in the assessment of gestational age in high risk babies.

Percutaneous transluminal coronary rotary ablation with Rotablator (European experience)

This study reports the results from 3 European centers using rotary ablation with Rotablator, a device that is inserted into the coronary artery and removes atheroma by grinding it into millions of tiny fragments. Rotary ablation was performed in 129 patients. Primary success (reduction in percent luminal narrowing greater than 20%, residual stenosis less than 50%, without complications) was achieved by rotary angioplasty alone in 73 patients (57%). An additional 38 patients (29%) had successful adjunctive balloon angioplasty. Thus primary success was achieved in 111 patients (86%) at the end of the procedure. Acute occlusion occurred in 10 patients (7.7%). Recanalization was achieved by balloon angioplasty in 7: urgent bypass grafting was undertaken in 2. Q-wave and non-Q-wave myocardial infarction occurred in 3 and 7 patients, respectively. No deaths occurred. Follow-up angiography was performed in 74 patients (60%). Restenosis, defined as the recurrence of significant luminal narrowing (greater than 50%) occurred in 17 of 37 patients (46%) who underwent rotary ablation alone, and 11 of 37 patients (30%) who had adjunctive balloon angioplasty. The overall angiographic restenosis rate was 37.8%. In conclusion, rotary ablation is technically feasible, and relatively safe in the coronary circulation. The low primary success rate reflects the limited size of the device, which can be introduced through available guiding catheters, and limits the use of rotary ablation as a stand-alone procedure to lesions in small arteries or in distal locations. No reduction in restenosis was seen, but the role of this device combined with balloon angioplasty in larger arteries needs to be further defined.

[Percutaneous sonographic angioplasty. Initial experimental results]

Aim of the present study was to examine in vitro the effects of a new ultrasound catheter system on atherosclerotic and normal vessels before employing the system in humans. 141 attempts were made on 32 vascular preparations obtained at autopsy. The vessels were opened longitudinally within 24 hours of death, dilated with gelatine and were then "treated" in a waterbath using varying degrees of pressure, angle of incidence, sound intensity and duration of sound. Macroscopic and histological examinations of the preparation showed no morphological change in normal vessels except evidence of pressure by the catheter. In particular, there were no perforations of the vessel wall. In atherosclerotic segments there was significant reduction in the size of plaques following treatment.

Short and long term results after intracoronary stenting in human coronary arteries: monocentre experience with the balloon-expandable Palmaz-Schatz stent

OBJECTIVE

Intracoronary stenting was designed to overcome acute complications after percutaneous transluminal coronary angioplasty and to achieve a reduced rate of restenosis, both of which are major limitations of this well accepted method for treating coronary heart disease. This report describes the experience at one centre with the implantation of balloon-expandable Palmaz-Schatz stents and focuses on device related complications and the short and long term angiographic outcome.

DESIGN

A retrospective data analysis.

PATIENTS

Stenting was attempted in 50 patients. Restenosis after an initially successful angioplasty procedure, inadequate postangioplasty results, saphenous coronary bypass stenoses, and bail-out situations were regarded as indications.

MAIN OUTCOME MEASURES AND RESULTS

In 49 of 50 attempted patients 61 stents (1-4 per patient) were implanted. Delivery problems occurred in three patients and were successfully overcome in two patients. Bail-out situations were successfully managed in 16 patients. Complications included acute thrombus formation within the stent immediately after implantation in one patient, which was successfully treated by thrombolysis. One patient was sent for bypass surgery the day after implantation; another died 10 days after implantation for unknown reasons. Subacute stent thrombosis occurred in seven patients 5-9 days after implantation and was successfully treated by thrombolysis or balloon angioplasty in five patients. Bleeding complications occurred in nine patients, five of whom required blood transfusions. Angiography showed long term vessel patency after 4-6 months in 31 (76%) of the 41 patients who were followed up, restenosis in six (14%), and reocclusion in four (10%). Late restenosis or reocclusion was found in five (15%) of 33 patients with a single stent in contrast to five (63%) of eight patients with multiple stents.

CONCLUSIONS

Balloon-expandable intracoronary stenting is a feasible method for treating the acute complications of balloon angioplasty. It reduced the rate of restenosis for single stent implantation. Subacute thrombotic events must be regarded as previously unknown and serious complications.

Results of intracoronary stents for management of coronary dissection after balloon angioplasty

Dissections after coronary balloon angioplasty are risk factors for acute or subacute vessel closures. Intracoronary stenting was developed to avoid these complications by pressing the intimal and medial flaps against the vessel wall, thus reducing the risk of acute thrombosis. A total of 22 stents were implanted into the coronary arteries of 15 patients with dissections after balloon angioplasty causing angina pectoris or ischemic electrocardiographic changes. Stent delivery was successful in all cases. In 1 patient acute stent thrombosis was documented and treated successfully by thrombolytic therapy. Another patient underwent coronary artery bypass surgery 24 hours later because of persisting angina. Angiograms after 24 hours documented vessel patency in the remaining 14 patients. Late control angiograms after 4 to 6 months were obtained in 12 of 14 patients. Vessel patency without significant restenosis was observed in 8 patients, restenosis in 3 and reocclusion in 1 patient. All 3 patients with multiple stent implantation had restenosis (n = 2) or reocclusion (n = 1), compared with 1 patient with single stent implantation. Thus, intracoronary stenting appears to be a secure and effective method of handling bailout situations caused by dissection after balloon angioplasty, with good long-term results when only a single stent is implanted.

[Angiographic and histologic findings in high frequency rotational ablation in coronary arteries in vitro]

High-frequency rotational angioplasty is a recently developed method for coronary angioplasty in the catheter laboratory. An elliptical burr tip (phi 1.25-2.0 mm) with embedded diamant chips (phi 40-50 microns) is rotated by a helical drive shaft at 150,000-180,000 rpm. The burr is advanced over a 0.009-inch coaxial guide wire. To show the effects of this approach in diseased and healthy vessels, which may be present before and behind a stenosis, 17 atherosclerotic coronary arteries of nine human hearts, and 18 normal coronary arteries of nine pig hearts were treated by this method in vitro. Standardized coronary angiography was performed before and after Rotablator treatment, followed by histological examination. From these data the burr-to-vessel-diameter ratio was calculated for each vessel segment and compared with the angiographical and histological outcome. Partial or complete removal of the circumference of the innermost vessel wall layers was observed regularly. The average removal of tissue in human coronary arteries was limited to the intimal layer and in the pig coronary arteries to the internal elastic membrane. In the pig coronary arteries no intimal tears or dissections occurred, in human coronary arteries tears could be seen frequently (13 of 17 vessels (76%)). Media tears were observed in 3 of 17 vessels; one (2%) media dissection could be demonstrated; no perforation occurred. Thus, the in vitro studies suggest that coronary rotational angioplasty has only a slight effect on the vessel segment next to a stenosis, regardless of the burr-to-vessel-diameter ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary stent implantation in acute vessel closure 48 hours after an unsatisfactory coronary angioplasty

We report the implantation of a balloon-expandable stent in a patient with acute vessel closure in the state of evolving myocardial infarction following 48 hr after unsatisfactory coronary angioplasty. The stent was implanted after successful recanalization of an occluded left anterior descending artery, with repeated unsatisfactory results of balloon angioplasty. Adjunct thrombolytic therapy was contraindicated. No residual stenosis was documented in immediate control angiograms, or after 24 hr, 3 weeks, and 4 months.