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C H Wittens

Publications and source records attributed to C H Wittens.

At least 19 recordsLinked to original sources
PubMed2005

Endovascular brachytherapy for the prevention of restenosis after femoropopliteal angioplasty. Results of the VARA Trial.

AIM: Endovascular brachytherapy (EBT) has been proposed as a method to prevent restenosis. We performed a prospective randomised multicenter study to determine its efficacy for prophylaxis of restenosis after femoropopliteal percutaneous transluminal angioplasty (PTA). METHODS: Patients with symptomatic stenotic or totally occluding lesions in the femoropopliteal artery were randomised to be treated with PTA plus EBT or PTA alone. In case of EBT, 14 Gy was applied by an 192Ir source to the vessel wall. Clinical examination, ankle-brachial pressure index (ABPI) and duplex ultrasound were planned after 6 and 12 months. The primary endpoint was significant restenosis of the treated segment at duplex ultrasound after 12 months. RESULTS: Fifty-three of the 60 patients who eventually met the inclusion criteria could be studied. After 12 months, restenosis rates were 44% (12/27) in the PTA group versus 35% (8/23) in the PTA + EBT group (c2 test, P=0.51). There was no difference in mandatory reintervention between the 2 groups. Overall, EBT resulted in an absolute risk reduction of significant restenosis of 9%, yet in patients with totally occlusive disease this reduction was 32%. CONCLUSIONS: This study suggests an effect of EBT on the occurrence of restenosis only after PTA of occluded femoropopliteal lesions. Due to a too small number of patients analysed this difference is not statistically significant.

Adult↗
PubMed2004

[Intestinal incarceration due to a Bochdalek's hernia].

A 67-year-old male presented with abdominal pain followed by respiratory distress. Imaging revealed a right-sided Bochdalek's hernia. At thoracotomy two days later, an incarcerated small bowel segment was removed, with a protracted post-operative course. In adults, a Bochdalek's hernia is rare and usually asymptomatic. However, when symptoms do occur, incarceration of the intestinal contents is frequent and accompanied by high mortality. The severely protracted course after delayed treatment of a symptomatic Bochdalek's hernia described here illustrates the importance of early recognition and surgical intervention.

Abdominal Pain↗
PubMed2001

A comparison of distal end-to-side and end-to-end anastomoses in femoropopliteal bypasses.

OBJECTIVES: to compare end-to-side (ETS) and end-to-end (ETE) distal anastomoses. Design retrospective cohort study. METHODS: retrospective cohort study. Between 1988 and 1992, 204 femoropopliteal bypasses (188 patients) were performed for claudication (55%), rest pain (22%) and tissue loss (23%). One hundred and eighteen ETS were compared with 86 ETE in terms of patency or a mean (range) follow-up of 68 (0.5-120) months. RESULTS: overall patency was 86%, 66% and 57% at 1, 5 and 8 years, respectively. Multivariate analysis showed ETE anastomoses (p =0.04), and also knee bypass ( p =0.05) and venous conduit ( p =0.004) to be significantly associated with impaired patency. CONCLUSIONS: ETE may improve femoropopliteal bypass patency.

Anastomosis, Surgical↗
PubMed2001

Complications in subfascial endoscopic perforating vein surgery: a report of two cases.

Subfascial endoscopic perforating vein surgery is a safe method for the division of incompetent perforating veins. Nevertheless, we report two cases with unfortunate complications: the posterior tibial artery and tibial nerve were damaged during the procedures. In one patient this resulted in a reintervention, but in both patients it resulted in permanent discomfort. We then present a guideline that may prevent damage to these critical structures.

Angioscopy↗
PubMed2001

Endoscopic versus open subfascial division of incompetent perforating veins in the treatment of venous leg ulceration: long-term follow-up.

PURPOSE: Subfascial division of incompetent perforating veins seems to be a successful treatment for patients with venous leg ulceration (CEAP 6). For postoperative wound complications, endoscopic techniques are more common than open subfascial division of incompetent perforating veins (Linton procedure). We investigated the long-term results of ulcer healing and recurrence rates and compared them with preoperative and postoperative duplex findings. METHODS: Patients with venous ulceration on the medial side of the lower leg were randomly allocated to endoscopic exploration or open exploration by means of the modified Linton approach. Ulcer healing and recurrence rates were documented. RESULTS: Thirty-nine patients were randomly allocated to exploration, 19 patients to open subfascial division of incompetent perforating veins (Linton group), and 20 patients to subfascial endoscopic division of incompetent perforating veins (SEPS group). During the follow-up period, four patients in the SEPS group died, all of causes other than the venous leg ulcer. Because of a squamous cell carcinoma that had developed in the venous ulcer, one patient in the SEPS group underwent a below-knee amputation. In a mean follow-up period of 50.6 months, the venous ulceration of all 18 patients in the Linton group who were available for follow-up initially healed. The recurrence rate in this group was 22% (4 patients). In the SEPS group, the mean follow-up period for 19 patients was 46.1 months, with the ulceration healing in 17 patients and a recurrence rate of 12% (2 patients). The presence of deep venous incompetence (DVI) did not influence the recurrence rates (P =.044, Fisher exact test), but it significantly influenced the development of new incompetent perforating veins (3 of 10 without DVI; 7 of 10 with DVI; P =.011, binomial test). CONCLUSION: The long-term follow-up results of the endoscopic division of perforating veins are comparable with those of the open division of perforating veins (modified Linton procedure).

Adult↗
PubMed2001

Flow measurements in dialysis shunts: lack of agreement between conventional Doppler, CVI-Q, and ultrasound dilution.

BACKGROUND: Measuring flow in dialysis shunts is recommended to predict imminent thrombosis. Multiple methods for measuring blood flow are in use. Numerous ultrasound protocols exist which determine volume flow using a conventional Doppler (CD) frequency shift analysis technique. All of these are subject to potentially large errors. Quantitative colour velocity index (CVI-Q) does not make use of the Doppler equation and is more precise in vitro. Ultrasound dilution (UD) measures access flow during dialysis in a non-operator-dependent way. The aim of the present study was to compare these three methods of measuring access flow in vivo for agreement with each other. METHODS: In 38 accesses flow was measured by CD, CVI-Q, and UD. All measurements were done during dialysis. Agreement was determined by intraclass correlation coefficient (ICC=R(i)) and Bland-Altman analysis. RESULTS: ICC between UD and CVI-Q was R(i)=0.56. ICC between UD and CD was R(i)=0.10, and ICC between CD and CVI-Q was R(i)=0.16. Bland-Altman analysis revealed a bias (mean difference) of -38 ml/min between UD and CVI-Q, a bias of 1129 ml/min between UD and CD, and a bias of 1167 ml/min between CVI-Q and CD. CONCLUSIONS: CD measurements did not agree with UD or CVI-Q much higher values were recorded with the former than with the latter two techniques. The agreement between UD and CVI-Q measurements is low but reasonable. Caution must be applied in comparing and interpreting values of access flow measured by different techniques.

Adult↗
PubMed1999

Plaque area increase and vascular remodeling contribute to lumen area change after percutaneous transluminal angioplasty of the femoropopliteal artery: an intravascular ultrasound study.

OBJECTIVE: The aim of the study was to assess the change in lumen area (LA), plaque area (PLA), and vessel area (VA) after percutaneous transluminal angioplasty (PTA) of the femoropopliteal artery. METHODS: This was a prospective study. Twenty patients were studied with intravascular ultrasound (IVUS) immediately after PTA and at follow-up examination. Multiple corresponding IVUS cross-sections were analyzed at the segments that were dilated by PTA (ie, treated sites; n = 168), including the most stenotic site (n = 20) and the nondilated segments (ie, reference sites; n = 77). RESULTS: At follow-up examination, both the PLA increase (13%) and the VA decrease (9%) resulted in a significant LA decrease (43%) at the most stenotic sites (P =.001). At the treated sites, the LA decrease (15%) was smaller and was caused by the PLA increase (15%). At the reference sites, the PLA increase (15%) and the VA increase (6%) resulted in a slight LA decrease (3%). An analysis of the IVUS cross-sections that were grouped according to LA change (difference >/=10%) revealed a similar PLA increase in all the groups: the type of vascular remodeling (VA decrease, no change, or increase) determined the LA change. At the treated sites, the LA change and the VA change correlated closely (r = 0.77, P <.001). At the treated sites, significantly more PLA increase was seen in the IVUS cross-sections that showed hard lesion or media rupture (P <.05). No relationship was found between the presence of dissection and the quantitative changes. CONCLUSION: At the most stenotic sites, lumen narrowing was caused by plaque increase and vessel shrinkage. Both the treated sites and the reference sites showed a significant PLA increase: the type of vascular remodeling determined the LA change at follow-up examination. The extent of the PLA increase was significantly larger in the IVUS cross-sections that showed hard lesion or media rupture.

Analysis of Variance↗
PubMed1999

Ultrasound-guided percutaneous coil embolization of incompetent perforating veins: not effective for treatment of venous ulcers and recurrent varicosities.

PURPOSE: To investigate the feasibility of ultrasound-guided percutaneous coil embolization of incompetent perforating veins as minimally invasive treatment for venous ulcers and recurrent varicosities in the lower leg. This could be an alternative to surgical ligation of perforating veins. MATERIALS AND METHODS: In 15 patients (six women, nine men; mean age, 50 years), 18 incompetent perforating veins in the lower leg were treated by ultrasound-guided percutaneous placement of embolization coils. RESULTS: Successful vein occlusion with one or more coils was achieved in 12 of the 18 veins (technical success rate, 67%). Clinical symptoms improved in only three of the 15 patients (clinical success rate, 20%). During follow-up (2-12 months), recanalization of coil embolized veins occurred in nine of the 12 initially occluded veins. CONCLUSION: Percutaneous ultrasound-guided coil embolization does not appear to be as effective as subfascial endoscopic perforator surgery in the treatment of incompetent perforator veins.

Embolization, Therapeutic↗
PubMed1998

Exercise therapy for intermittent claudication: a review of the quality of randomised clinical trials and evaluation of predictive factors.

OBJECTIVE: To establish the effect of exercise therapy in patients with intermittent claudication and to identify outcome predictors for exercise training. DESIGN: A methodological study of randomised clinical trials. METHODS: A quality assessment of all eligible studies was performed, using a list of methodological criteria. A weighing scale for the criteria was developed, based on four main categories: study population, intervention, outcome variables and data presentation/analysis. RESULTS: Ten studies were included in the analysis. Seven randomised clinical trials had a methodological score of 60 or more points (maximum 100), and were considered to be of good quality. The mean of the methodological score was 62.5 (S.D. 8.5). Improvement in pain-free/maximum walking distance/time ranged from 28-210% (mean 105, S.D. 55.8). Only one study evaluated outcome predictors for exercise therapy. CONCLUSIONS: All studies reported a positive effect of exercise therapy on walking distance in patients with intermittent claudication, but no predictive factors were clearly identified. Future research efforts should focus on improving the quality of clinical research for patients with intermittent claudication and developing optimal rehabilitation programs.

Exercise Therapy↗
PubMed1998

The effect of exercises on walking distance of patients with intermittent claudication: a study of randomized clinical trials.

BACKGROUND AND PURPOSE: There is no consensus about the indication for exercises for patients with intermittent claudication of the lower extremity and the characteristics of an exercise program to improve walking distance. The effect of walking is assessed by a systematic review of randomized clinical trials. METHODS: Literature databases were accessed using the relevant key words. The references of identified articles were screened for additional studies. A checklist was developed to screen the studies with respect to the variables of interest. A methodological assessment form was developed to assess the methodological quality of the studies (maximum possible score: 100). RESULTS: Eighty-two articles were identified, of which 21 studies were considered relevant for inclusion in the review. Following the analysis of the articles, 11 studies were for various reasons eliminated, leaving 10 studies for the systematic review. The score for methodological quality of the studies ranged from 47 to 75 (mean = 62.5, SD = 8.5). Percentage of improvement in walking distance or time ranged from 28% to 210% (mean = 105%, SD = 55.8%). CONCLUSION AND DISCUSSION: All studies showed that walking exercises improved walking distance in patients with intermittent claudication. Further research is needed to determine the optimal exercise program, the effect of adherence to the treatment protocol, and the duration of the effects following a formal exercise program.

Exercise Therapy↗
PubMed1997

Endoscopic versus open subfascial division of incompetent perforating veins in the treatment of venous leg ulceration: a randomized trial.

PURPOSE: Subfascial division of incompetent perforating veins plays an important role in the surgical treatment of patients with venous ulceration of the lower leg. To minimize the high incidence of postoperative wound complications after open exploration, endoscopic approaches have recently been developed. We carried out a prospective, randomized comparison of open and endoscopic treatment of these patients that was aimed at ulcer healing and postoperative wound complications. METHODS: Patients with current venous ulceration on the medial side of the lower leg were randomly allocated to open exploration by the modified Linton approach or endoscopic exploration by use of a mediastinoscope. RESULTS: Thirty-nine patients were randomized, 19 to open exploration and 20 to endoscopic exploration. The incidence of wound infections after open exploration was 53%, compared with 0% in the endoscopic group (p < 0.001). Patients in the open group needed longer hospital stays (mean, 7 days; range, 3 to 39 days) than patients in the endoscopic group (mean, 4 days; range, 2 to 6 days; p = 0.001). Four months after operation, the ulcers of 17 patients (90%) in the open group and 17 patients (85%) in the endoscopic group had healed. During a mean follow-up of 21 months (range, 16 to 29 months), no recurrences were noticed in either group. CONCLUSIONS: Endoscopic division of incompetent perforating veins is equally as effective as open surgical exploration for the treatment of venous ulceration of the lower leg but leads to significantly fewer wound healing complications. Endoscopic division is therefore the preferred method.

Adult↗
PubMed1997

Validation of duplex ultrasonography in detecting competent and incompetent perforating veins in patients with venous ulceration of the lower leg.

PURPOSE: Incompetent perforating veins play an important role in the etiologic mechanism of venous ulceration and recurrent varicose veins. The anatomic and functional status of the venous system can be evaluated by duplex ultrasonography. To determine the value of this technique in the identification of competent and incompetent perforating veins, a prospective study was performed. METHODS: In patients who underwent subfascial exploration for venous ulceration of the lower leg, the preoperative findings of duplex ultrasonography were compared with the findings at surgical exploration. RESULTS: In 20 consecutive patients, 42 incompetent and 8 competent perforating veins were detected by duplex ultrasonography. During operation the location of all 50 perforating veins appeared to be predicted correctly. Eleven additional perforating veins that had not been detected by duplex ultrasonography were found during operation. The sensitivity and specificity of duplex ultrasonography in predicting the site of perforating veins at the medial side of the lower leg in our study were 79.2% and 100%, respectively, for incompetent perforating veins and 82% and 100%, respectively, for competent and incompetent perforating veins. CONCLUSION: These figures indicate that duplex-guided local exploration of the lower leg in patients with venous ulceration as a result of incompetent perforating veins would miss a substantial number of perforating veins, possibly leading to incomplete healing or recurrent ulceration.

Adult↗
PubMed1997

Efficacy of subfascial endoscopy in eradicating perforating veins of the lower leg and its relation with venous ulcer healing.

PURPOSE: The purpose of this study was to investigate the efficacy of subfascial endoscopy by use of a mediastinoscope in the identification and ligation of incompetent perforating veins in patients with venous ulceration of the lower leg. METHODS: All patients who underwent subfascial endoscopy for venous ulceration between Jan. 1, 1994, and Mar. 1, 1995, at the Sint Franciscus Gasthuis in Rotterdam underwent duplex ultrasound scans of the lower leg before and 6 weeks after operation. The number and localization of the perforating veins on the mediodorsal side were compared with the findings during subfascial endoscopy. RESULTS: In 20 patients, preoperative duplex examination showed 46 incompetent and six competent perforating veins. During operation the site of 43 incompetent and all competent perforating veins was confirmed. Five additional perforating veins were found at operation (false-negatives). Postoperative duplex ultrasound scans showed six incompetent perforating veins (four persisting and two recurring perforating veins) in four patients, of which the ulcers did not heal in three. The ulcers of the other 17 patients healed. CONCLUSIONS: Subfascial endoscopy is an efficient technique in identifying incompetent perforating veins in patients with chronic ulceration of the lower leg. The persistence of incompetent perforating veins is related to failure of ulcer healing.

Adult↗
PubMed1997

Residual arteriovenous fistulae after "closed" in situ bypass grafting: an overrated problem.

OBJECTIVES: To prospectively evaluate the incidence and consequences of residual arteriovenous (AV)-fistulae after "closed" in situ bypass grafting. METHODS: In 34 patients, 35 "closed" in situ bypasses were performed. Postoperative assessment of residual AV-fistulae and bypass patency was performed with duplex scanning. RESULTS: Postoperative mortality was 3%. During 35 "closed" in situ bypass procedures 216 side branches were coil embolised. Postoperatively 39 AV-fistulae were detected (15% of the total number of 216 + 39 = 255 side branches). Of these, 13 (5%) closed spontaneously. Fifteen (6%) remained unchanged and 11 (4%) were treated. In three patients four asymptomatic residual AV-fistulae were treated. In four patients seven symptomatic AV-fistulae were treated for: decreased distal bypass flow in one; persistent leg oedema in one; pain and redness of the skin in two. One-year primary patency was 80% (SE 8.4%). Residual AV-fistulae were detected in none of six bypass occlusions during follow-up. CONCLUSION: Residual AV-fistulae detected following "closed" in situ bypass grafting only need treatment if they are symptomatic, which is uncommon.

Aged↗
PubMed1997

Comparison of cost affecting parameters and costs of the "closed" and "open" in situ bypass technique.

OBJECTIVES: The "closed" in situ bypass results in a reduction of wound complications compared to the "open" technique. This advantage is partly diminished by extra costs for the "closed" procedure and a larger percentage of residual arteriovenous (AV)-fistulae. This aim of this study was to analyse costs related to "closed" and "open" procedures. METHODS: The cost affecting parameters: (1) duration of operation; (2) length of hospital stay; and (3) number of treated residual AV-fistulae, were analysed in a randomised group of 73 patients (35 "closed" and 38 "open") in two centres. In addition, costs of the operation, nursing care and treatment of AV-fistulae were analysed. RESULTS: The "closed" and "open" group showed a median duration of operation of 210 min (range 105-570) and 154 min (range 90-355) (p < 0.05), length of hospital stay of 16 days (range 5-51) and 25 days (range 12-65) (p < 0.01), and a percentage of patients treated for residual AV-fistulae of 40% and 5%, respectively (p < 0.01). The median "closed" operation was US$798 more expensive than the "open". Median postoperative care was US$2664 less for the "closed" group. Mean estimated costs for treatment of AV-fistulae was US$9 in the "open" and US$167 in the "closed" group. CONCLUSION: The "closed" in situ vein bypass technique is cost-effective in comparison with the "open" technique.

Aged↗
PubMed1997

Endoscopic ligation of perforating veins using a mediastinoscope.

Incompetent perforating veins play a major role in venous ulceration and recurrence of varicose veins. To reduce postoperative wound problems associated with classic subfascial exploration of the lower leg, endoscopic approaches have been developed. We describe a technique that makes use of a mediastinoscope to explore the subfascial area. This inexpensive and readily available instrument is present in most operating rooms. Although a learning curve must be anticipated, the results of this technique in retrospective studies are promising.

Endoscopes↗
PubMed1996

The value of pre-operative ultrasound mapping of the greater saphenous vein prior to 'closed' in situ bypass operations.

OBJECTIVE: The aim of this study was to test pre-operative ultrasound mapping for the detection of duplications and narrow vein segments of the greater saphenous vein (GSV) used as bypass for occlusive arterial disease surgery. PATIENTS AND METHODS: In 44 patients pre-operative ultrasound findings of duplications and lumen assessment of GSV were compared to the per-operative findings. RESULTS: In nine patients (20%) the pre-operative ultrasound examination showed a duplication. Pre-operative ultrasound had missed a duplication in two cases but had instead shown a narrow segment in both. The pre-operative ultrasound assessment of lumen diameter showed a narrow lumen segment in 10 of the 44 patients. In one patient a per-operatively narrow lumen had not been seen on pre-operative ultrasound. CONCLUSION: Pre-operative ultrasound mapping of the GSV is a sensitive tool for detection of duplications and narrow vein segments. Since these anatomical variations provide important information for the vascular surgeon, before performing a 'closed' in situ bypass operation, pre-operative vein mapping should be considered when planning such a procedure.

Aged↗