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Biomedical subjects

I Nyamekye

Publications and source records attributed to I Nyamekye.

At least 19 recordsLinked to original sources
PubMed1999

Clinical study of adjuvant photodynamic therapy to reduce restenosis following femoral angioplasty.

BACKGROUND: Photodynamic therapy (PDT) reduces neointimal hyperplasia and negative remodelling following balloon injury in small and large animal models. This clinical study investigated the role of adjuvant PDT following femoral percutaneous transluminal angioplasty (PTA). METHODS: Eight PTAs in seven patients (two women) with a median age of 70 (range 59-86) years were performed with adjuvant PDT. All patients had previously undergone conventional angioplasty at the same site which resulted in symptomatic restenosis or occlusion between 2 and 6 months. Each was sensitized with oral 5-aminolaevulinic acid 60 mg/kg, 5-7 h before the procedure. Following a second femoral angioplasty, up to 50 J/cm2 red light (635 nm) was delivered to the angioplasty site via a laser fibre within the angioplasty balloon. Patients were kept in subdued light overnight and discharged the following day. Outcome was assessed by duplex imaging at 24 h, 1, 3 and 6 months and by intravenous digital subtraction angiography at 6 months. A peak systolic velocity ratio (PSVR) of more than 2.0 at the angioplasty site was taken to represent restenosis. RESULTS: All patients tolerated the procedure well without adverse complications or death. All were rendered asymptomatic which was sustained throughout the study interval. All vessels remained patent and no lesion attained the duplex definition of restenosis. Median (interquartile range) PSVR across stenotic segments was 4.7 (3.7-5.7) before angioplasty, 1.1 (0.9-1.3) at 24 h and 1.4 (1.0-1.8) at 6 months after intervention (P = 0.04 compared with preoperative value). CONCLUSION: This pilot study suggests that endovascular PDT is safe and may reduce restenosis follow- ing angioplasty. The data justify a randomized controlled trial.

Aged↗
PubMed1998

The diagnosis and management of mixed arterial/venous leg ulcers in community-based clinics.

OBJECTIVES: To assess a management protocol for mixed arterial/venous leg ulcers in a community service. DESIGN: Two-year prospective study of outcome with intention of assessing limbs with mixed arterial/venous ulcers when managed by a new protocol. METHOD: Limbs were assessed for venous reflux by duplex and arterial insufficiency by ankle-brachial pressure index (ABPI) and defined into three categories: ABPI > 0.85, 0.5 > ABPI < or = 0.85 (moderate), ABPI < or = 0.5 (severe). Four-layer compression was applied to limbs with normal arteries. Modified compression was applied to limbs with venous and moderate arterial disease with treatment failure triggering arterial imaging and revascularisation. Limbs with venous and severe arterial disease were investigated for revascularisation. RESULTS: Of 267 consecutive limbs, 221 had pure chronic venous ulcers and 46 had mixed arterial/venous ulcers with 33 having moderate and 13 having severe arterial disease. Thirty-six week healing rates for chronic venous, moderate arterial/venous and severe arterial/venous ulcers were 70%, 64% and 23%, respectively. CONCLUSION: Limbs with mixed moderate arterial/venous ulcers achieved rates comparable with venous ulcers with this protocol although nurse-led surveillance was required. Limbs with mixed severe arterial/venous ulcers healed slowly despite an aggressive approach to correct arterial disease.

Aged↗
PubMed1998

Clinicopathological evidence that neovascularisation is a cause of recurrent varicose veins.

OBJECTIVES: Recurrent varicose veins may result from poor initial surgical technique or progression of varicosities in collateral veins. In some cases new veins may develop at the saphenofemoral junction (neovascularisation) and cause recurrent saphenofemoral incompetence. This was a histological study of recurrent varicose veins. DESIGN: This clinicopathological study included 20 patients (median age 55 years) who had surgery for recurrent saphenofemoral incompetence. MATERIALS AND METHODS: A total of 28 legs had groin re-exploration with repeat flush saphenofemoral ligation. The venous tissue block from the saphenofemoral region (including the proximal thigh varicosity) was excised and orientated for histological analysis. Evidence of neovascularisation was sought using routine histological sections and S100 immunohistochemistry. RESULTS: At operation, thin-walled, serpentine neovascular veins were detected clinically as the principal cause of recurrence in 19 groins. In five groins recurrence was due to a residual missed vein at the saphenofemoral junction, and in four recurrence was caused by cross groin collaterals. On histological sections, evidence of neovascularisation was present in 27 of 28 groins. In eight it co-existed with the veins missed at the original operation but it was the sole identified cause of recurrent saphenofemoral incompetence in 19 (68%) groins. CONCLUSIONS: Neovascularisation was the principal cause of recurrent saphenofemoral incompetence in this series.

Adult↗
PubMed1998

Influence of a specialised leg ulcer service and venous surgery on the outcome of venous leg ulcers.

OBJECTIVES: To assess the influence of a vascular-led community service on the outcome of chronic leg ulcers. DESIGN: Before and after study. METHOD: Healing and recurrence were compared between ulcerated limbs (n = 149) from a random sample of 200 patients treated in the community and consecutive limbs (n = 200) from 180 patients treated in specialised clinics. In these clinics, vascular disease was routinely identified with venous duplex and ankle-brachial pressure index. Surgery was offered if superficial vein reflux alone was detected. Compression bandaging was applied to limbs with ABPI > 0.85. Healed limbs were treated with compression hosiery. RESULTS: After the clinics were introduced, the 12 and 24-week healing rates increased from 12 and 29 per cent to 53 and 68 per cent respectively (p < 0.01), and the 6 and 12 month recurrence rates decreased from 43 and 54 per cent to 21 and 23 per cent respectively (p < 0.01). Superficial venous surgery reduced recurrence at 1 year to 9 per cent. CONCLUSION: Outcome of leg ulcers is improved in a vascular-led community service. Routine surgical correction, in cases of reflux limited to the superficial system, may further reduce the chance of recurrence.

Aged↗
PubMed1998

Quality of life after transthoracic endoscopic sympathectomy for upper limb hyperhidrosis.

OBJECTIVE: To assess the outcome after transthoracic endoscopic sympathectomy (TES) for upper limb hyperhidrosis. DESIGN: Prospective cohort study. SETTING: District general hospital. SUBJECTS: Consecutive patients undergoing TES for upper limb hyperhidrosis over a fifteen month period. INTERVENTIONS: One-stage bilateral TES. MAIN OUTCOME MEASURES: Change in quality of life as shown by the Short Form-36 health assessment questionnaire. RESULTS: Sixteen patients (11 women and 5 men, median age 26 years) underwent operation without complications. At median follow-up of 6.2 months, symptomatic improvement was found in 26 of 32 limbs treated (82%). Truncal compensatory hyperhidrosis was reported by 13 patients but was severe in only three. There were significant improvements in social function (p = 0.01) and mental health (p = 0.025) as assessed by the SF-36. CONCLUSION: Despite a high incidence of compensatory hyperhidrosis, TES improved both the symptoms and overall quality of life in patients with upper limb hyperhidrosis.

Adolescent↗
PubMed1997

Thrombosis and restenosis after peripheral angioplasty: does acute 111indium-platelet accumulation predict angioplasty outcome?

OBJECTIVES: Use of platelet deposition to predict failure following angioplasty. DESIGN: Prospective study of angioplasty patients in a 9 months surveillance period. MATERIALS: Thirty-eight successful angioplasty patients. METHODS: Autologous 111indium-labelled platelets were re-injected immediately after angioplasty. Gamma camera and probe measures of radioactivity were obtained daily for 2-4 days and compared to a reference site to obtain a radioactivity ratio. Patient follow up was with duplex and arteriography from day 0 to 9 months or at angioplasty failure. RESULTS: Thirty-one patients remained asymptomatic; two developed acute occlusion and five developed restenosis. Platelet accumulation (increased mean radioactivity ratio) occurred at all angioplasty sites and was significantly higher after acute occlusion (camera: 2.93 and probe: 1.93) compared to asymptomatic patients (camera: 1.25 and probe: 1.15) and restenotic patients (camera: 1.31 and probe: 1.23). Radioactivity ratio was not different in patients who later developed restenosis. CONCLUSION: 111Indium platelet radioactivity effectively detected acute angioplasty reocclusions, but was unable to predict subsequent angioplasty restenosis.

Adult↗
PubMed1997

Unsuspected rectal adenocarcinoma causing a urinoma.

A middle-aged man with a history of Hodgkin's disease presented with loin pain and microscopic hematuria. Radiologic studies demonstrated a urinoma secondary to ureteric obstruction at the pelvic brim. Percutaneous nephrostomy was performed to decompress the collection and a ureteric stent inserted to maintain drainage. Laparotomy revealed an unsuspected rectal adenocarcinoma. A metastatic deposit compressing the ureter had produced the urinoma. Metastatic colorectal carcinoma is a rare cause of urinoma.

Adenocarcinoma↗
PubMed1997

A hidden complication of out-patient arteriography.

Rapid progression of arterial disease may occur between out-patient diagnostic arteriography and therapeutic angioplasty. We have studied the incidence of this complication in our institution. Sixty-seven consecutive out-patient arteriograms were assessed. Thirty-four patients were re-admitted for angioplasty within a median interval of 4 weeks (range 5 days-3 months). We compared immediate pre-angioplasty arteriograms with the out-patient images. Twenty-five pairs of films showed disease progression. Three patients showed new disease, one remote from the site of the arterial lesion and two in the opposite limb. Six patients showed marked progression of the original disease. The policy of delayed treatment after out-patient arteriography may require reconsideration in the light of our complication rate of 18%.

Aged↗
PubMed1996

Colour duplex ultrasonography in the rational management of chronic venous leg ulcers.

Colour duplex ultrasonographic imaging has largely replaced venography in the assessment of lower-limb venous disorders. This is a study of the use of duplex in the management of patients with chronic venous ulceration in community ulcer clinics. Patients with chronic leg ulceration and an ankle: brachial pressure index of 0.85 or greater were studied. Assessment of venous competence in both the deep and superficial systems of the affected and unaffected legs was performed using colour venous duplex imaging. Reflux was defined as reverse flow for greater than 1 s after manual calf compression. One hundred consecutive patients were assessed over 15 months. Of 111 ulcerated legs, 96 had active ulceration, while 15 had been ulcerated within the previous 6 months. Fifty-seven (51 per cent) of the 111 ulcerated legs had superficial incompetence alone (88 per cent long saphenous system or its perforators, 12 per cent short saphenous system). Six legs (5 per cent) had isolated deep venous incompetence. Forty-two legs had mixed superficial and deep venous reflux; 22 of these had undergone previous venous surgery. Colour venous duplex assessment demonstrated superficial venous disease in approximately half of limbs with chronic leg ulceration. Venous dysfunction in these patients is potentially curable by surgery.

Adult↗
PubMed1996

The significance of increased 111indium platelet accumulation at post-angioplasty sites.

We assessed prospectively the significance of 111indium labelled platelet accumulation following angioplasty procedures in 12 patients (9 femoral angioplasties (2 laser, 1 atherectomy) and 3 iliac stents). Autologous 111indium labelled platelets were re-injected immediately after angioplasty. Radioactivity was measured over treated and reference sites, by single probe and gamma camera, and expressed as a radioactivity ratio (RR). All patients had duplex ultrasound assessment and occlusions were confirmed by arteriography. RR was always raised after angioplasty. Three patients who had acute occlusions showed markedly raised average RRs (significant at 99% ANOVA). RR was not raised after laser assisted angioplasty, however, our numbers were small. 111Indium platelet radioactivity did not predict subsequent occlusion after angioplasty but effectively detected existing acute post-angioplasty occlusions.

Angiography↗
PubMed1996

Non-invasive assessment of arterial stenoses in angioplasty surveillance: a comparison with angiography.

OBJECTIVES: Comparison of non-invasive arterial measurements with angiography and their use for angioplasty surveillance. DESIGN: Prospective assessments of arterial stenoses in patients undergoing angioplasty in a 9 month surveillance period. MATERIALS: Fifty consecutive patients undergoing angioplasty. METHODS: (i) One hundred and thirty-one sets of clinical assessments, ankle brachial Doppler pressure indices and colour Duplex velocities and diameters were compared to time-matched angiographic diameter stenosis. (ii) Fifty patients undergoing femoropopliteal angioplasty (32 stenoses and 18 occlusions) were studied with ankle branchial Doppler pressure indices and colour Duplex and angiography during a 9 month surveillance period. RESULTS: (i) Symptoms, pulses, resting ABPI, and exercise ABPI showed no useful correlation with angiography. Duplex velocity ratio and Duplex diameters showed correlation and agreement with angiography respectively. (ii) On surveillance, restenosis was universal but not always clinically significant. Angioplasty caused a rapid improvement in ABPI and imaging studies which worsened at later times. ABPI did not predict clinical failure however, Duplex and angiography predicted all clinical failures. CONCLUSIONS: Restenosis should be assessed with imaging of the angioplasty site during angioplasty surveillance.

Adult↗
PubMed1996

Inhibition of intimal hyperplasia in balloon injured arteries with adjunctive phthalocyanine sensitised photodynamic therapy.

OBJECTIVES: We investigated the effects of Photodynamic therapy (PDT) using Aluminium disulphonated phthalocyanine (AlS2Pc) on experimental intimal hyperplasia (FCIH). MATERIALS AND METHODS: (a) Pharmacokinetics: Normal rats were injected with Als2Pc and carotid artery fluorescence was measured. (b) Normal artery PDT: Sensitised rats underwent carotid artery laser irradiation (50J/cm2, 675nm) and were assessed after 3 and 14 days and 1-6 months. (c) PDT: Rats underwent standard carotid artery balloon injury immediately prior to PDT and arteries were assessed at 2 to 26 weeks, together with laser, AlS2Pc, and untreated controls. CHIEF OUTCOME MEASURES: (a) Fluorescence intensity in different arterial layers. (b) Medial smooth muscle cell counts per high power field (light microscopic). (c) Percentage amount of FCIH (area of intimal hyperplasia) as a ratio of the IEL (area enclosed by the internal elastic lamina). RESULTS: (a) AlS2Pc fluorescence intensity increased with increasing dosage, with maximal fluorescence in the arterial media at 30 min. (b) PDT produced medial cell depletion at 3 days and persisted over 6 months without loss of vessel integrity. (c) PDT completely inhibited FCIH at 2 and 4 weeks. This was partial at 6 to 26 weeks (51% of untreated level). PDT inhibition of FCIH was significantly greater than in any of the control groups. p < 0.0001. Mann-Whitney Test. CONCLUSION: Adjunctive AlS2Pc sensitised photodynamic therapy inhibits experimental intimal hyperplasia, by causing medial smooth muscle cell depletion. This offers a new approach to the management of angioplasty restenosis in patients.

Angioplasty, Balloon↗
PubMed1995

Photodynamic therapy of normal and balloon-injured rat carotid arteries using 5-amino-levulinic acid.

BACKGROUND: Although the management of atherosclerotic disease by the use of balloon angioplasty is widespread, the treatment is limited by restenosis in 30% to 50% of cases. Fibrocellular intimal hyperplasia, the main cause of restenosis, arises from proliferation and migration of medial smooth muscle cells (SMC) into the intimal layer. Factors leading to intimal hyperplasia are incompletely understood, and drugs have universally failed to influence clinical restenosis. Photodynamic therapy (PDT), the light activation of photosensitizing drugs to generate cytotoxic mediators, may have potential as prophylaxis for intimal hyperplasia. 5-Amino-levulinic acid-induced protoporphyrin IX (ALA-PPIX), a naturally occurring porphyrin precursor, and its product, -PPIX, offers a novel method of sensitization for PDT. We have investigated the pharmacokinetics of ALA in arteries and the effects of ALA-PPIX-sensitized PDT on normal and balloon-injured arteries. METHODS AND RESULTS: ALA (20 to 200 mg/kg) was injected into healthy rats, and PPIX fluorescence was measured in the carotid arteries. In a second group of rats, the exposed carotid artery was laser illuminated (50 J/cm2, 630 nm) 30 to 90 minutes after sensitization. Three and 14 days after PDT, histological sections from treated arteries were analyzed by light microscopy. Subsequently, two new groups of rats underwent PDT (ALA, 100 mg/kg; laser, 50 J/cm2, 630 nm [at 60 to 90 minutes]). The left carotid arteries underwent balloon angioplasty by intraluminal passage of a Fogarty FG2 catheter immediately before irradiation. These rats were killed at 14 and 28 days together with laser-only, ALA-only, and untreated control rats. The arteries were perfusion-fixed in vivo. ALA-PPIX induced arterial media fluorescence in a dose-dependent manner. In the normal arteries, PDT produced a dose-dependent cellular depletion in the treated arterial segment at 3 days, and this was complete with 100 and 200 mg/kg of ALA. At 14 days, the media remained acellular, although the endothelial lining had regenerated. In the balloon-injured arteries, PDT produced complete inhibition of intimal hyperplasia at both 14 and 28 days (0%). This was significantly greater than that produced by any of the control rats (34% to 69% and 37% to 66% at the two times, respectively). Significance was at 99% using ANOVA and Fisher's PLSD test. No hemorrhage, thrombosis, or aneurysm formation was seen. CONCLUSIONS: ALA-PPIX-sensitized PDT applied at the time of angioplasty effectively inhibits experimental intimal hyperplasia development in rats. This may offer a new approach to the management of angioplasty restenosis in patients.

Aminolevulinic Acid↗
PubMed1994

Advanced gastrointestinal malignancy or benign inflammatory disease? An unusual presentation of sclerosing mesenteritis. Report of a case.

The presentation of change of bowel habit, weight loss, muscle wasting, ascites, and the surgical appearance of "omental cake" are almost pathognomonic of advanced gastrointestinal malignancy. In our case, these symptoms represented a unique presentation of the condition sclerosing mesenteritis. Despite its rarity, the clinician should be aware of this "sheep in wolf's clothing," the clinical importance of which lies in the condition's benign and self-limiting course and imparts to the patient a prognosis and treatment that could not be further removed from that of advanced malignancy. Investigations that may be helpful to the surgeon in distinguishing the condition from carcinomatosis and avoiding unnecessary laparotomy include preoperative colonoscopy, barium enema, cytology of any ascites, and intraoperative frozen section biopsy. Treatment of the condition is conservative unless it has caused extrinsic bowel obstruction.

Ascites↗