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Biomedical subjects

M H Simms

Publications and source records attributed to M H Simms.

At least 19 recordsLinked to original sources
PubMed2006

Oesophageal substitution with free and pedicled jejunum: short- and long-term outcomes.

In children, the indications for oesophageal substitution are principally, long gap oesophageal atresia (OA), severe anastomotic disruption following primary repair of OA and severe caustic or peptic strictures. We present an outcome review of eight cases who underwent oesophageal substitution with jejunum at our institution between 1986 and 2001. The purpose of this study was to evaluate our experience with free/pedicled jejunal grafts and its long-term outcome as an oesophageal substitute. Operative and postoperative outcome with free and pedicled jejunal grafts in four cases of pure OA, two cases of OA and distal tracheo-oesophageal fistula (TOF), one patient with a high retrolaryngeal oesophageal web and one case of severe caustic oesophageal stricture. Six patients had an oesophagostomy and a gastrostomy fashioned previously. Eleven free jejunal grafts were performed in six patients (three intraoperative redo interpositions for immediate graft loss, three separate grafts in one patient and two free grafts in two patients). One patient's pedicled jejunal graft proximally required microvascular anastomosis while the other had a pedicled graft without microvascular anastomosis. Early postoperative complications included four upper anastomotic leaks (three free grafts, one pedicled with microvascular support), pneumothorax requiring prolonged ventilation and Horner's syndrome. Recurrent laryngeal nerve injury occurred in the patient who had a high retrolaryngeal oesophageal web. During follow up (5-18 years) late complications of upper anastomotic stricture in four patients and graft redundancy with subsequent kinking of the lower anastomosis were observed in one patient. Three patients established a complete oral diet; a further three patients relied on supplemental gastrostomy feeds and one patient is entirely gastrostomy fed. There were two late deaths, one from aspiration and the other from a severe asthmatic attack (5 and 7 months postoperatively, respectively). Our results indicate that there are significant complications related to the use of free jejunal grafts. Early recognition and treatment are of paramount importance in the ultimate achievement of a successful technical outcome.

Adolescent↗
PubMed2005

The effects of hydroxyethyl starch compared with gelofusine on activated endothelium and the systemic inflammatory response following aortic aneurysm repair.

OBJECTIVE: To investigate the effect of HES, used as a plasma volume expander, on endothelial cell activation induced by ischaemia-reperfusion in humans. MATERIAL AND METHODS: Forty patients undergoing elective infrarenal aneurysm repair were randomised to receive either gelatine or hydroxyethyl starch solution as plasma expanders. The anaesthetic technique was standardised. All patients received the same crystalloid as per standard protocol. Urine samples and blood samples were collected at various times for assessment of microalbuminuria and von Willebrand factor (vWf) and CRP. RESULTS: The peak C-reactive protein was significantly lower in the patients treated with HES than those treated with gelofusine [142 mg/L (113,196 mg/L) vs 246 mg/L (189,291 mg/L) mg/L, P < 0.01, Mann-Whitney test]. The peak ACR was also significantly lower in the HES treated patients (9.3 mg/mmol vs 23.3 mg/mmol, P < 0.05). The plasma level of vWf was significantly higher in the gelofusine treated patients than those treated with HES [173.5 U/dl Vs 80.5 U/dl, P < 0.001, at 4 hr; 160 U/dl Vs 82.5 U/dl, P < 0.001, at 8 hr; 191 U/dl Vs 100.5 U/dl, P < 0.001, at 12 hr; 209 U/dl Vs 81.0 U/dl, P < 0.001, at 24 hr]. CONCLUSION: HES may damp down the systemic inflammatory response and reduce endothelial cell dysfunction.

Aged↗
PubMed2004

Ankle sprain: an unexpected complication.

Blunt arterial injury is usually caused by high velocity trauma and can result in intimal dissection. We present a case of a professional footballer who sustained an intimal tear of the posterior tibial artery following a minor eversion injury of the ankle. The injury was noticed because of the physical demands of this patient's profession. This was confirmed by an arteriogram and was treated with bypass surgery using an arm vein. Arterial intimal injury has not been reported previously with this type of injury. A high index of suspicion is needed to diagnose these injuries and revascularisation either by primary anastomosis or vein interposition graft is suggested.

Adult↗
PubMed2004

Randomized study comparing the effects of hydroxyethyl starch solution with Gelofusine on pulmonary function in patients undergoing abdominal aortic aneurysm surgery.

BACKGROUND: Restoring blood flow to ischaemic tissue can cause lung damage with pulmonary oedema. Hydroxyethyl starch (HES) solution, when used for volume replacement, may modify and reduce the degree of ischaemia-reperfusion injury. We compared the effects of HES solution with those of Gelofusine solution on pulmonary function, microvascular permeability and neutrophil activation in patients undergoing elective infrarenal abdominal aortic aneurysm surgery. METHODS: Forty patients were randomized into two groups. The anaesthetic technique was standardized. Lung function was assessed with the PO(2)/FI(O(2)) ratio, respiratory compliance, chest x-ray and a score for lung injury. Microvascular permeability was determined by measuring microalbuminuria. Neutrophil activation was determined by measurement of plasma elastase. RESULTS: Four hours after surgery, the median (quartile values) PO(2)/FI(O(2)) ratio was 40.3 (37.8, 53.1) kPa for the HES-treated patients compared with 33.9 (31.2, 40.9) kPa for the Gelofusine-treated patients (P<0.01, Mann-Whitney test). The respiratory compliance was 80 (73.5, 80) ml cm(-1) H(2)O in the HES-treated patients compared with 60.1 (50.8, 73.3) ml cm(-1) H(2)O in the Gelofusine-treated patients (P<0.01, Mann-Whitney test). The lung injury score 4 h after surgery was less for the patients treated with HES compared with the patients treated with Gelofusine (0.33 vs 0.71, P=0.01, Wilcoxon rank sum test). Mean (SD) plasma elastase was less in the HES-treated patients on the first postoperative day (1.96 (0.17) vs 2.08 (0.24), P<0.05). The log mean microalbuminuria was less in the HES-treated patients (0.41 vs 0.91 mg mmol(-1), P<0.05). This difference in microvascular permeability was associated with different volumes of colloid required to maintain stable cardiovascular measurements in the two groups of patients studied (3000 vs 3500 ml, P<0.01, Mann-Whitney test). CONCLUSION: Compared with Gelofusine, the perioperative pulmonary function of patients treated with HES after abdominal aortic aneurysm surgery was better.

Aged↗
PubMed2003

Microtibial embolectomy.

BACKGROUND: microtibial embolectomy is an important technique in cases of limb threatening acute arterial occlusion affecting native crural and pedal vessels. It is particularly useful when thrombolysis is contraindicated or ineffective as in "trash foot". METHODS: in order to evaluate the efficacy of this technique, a retrospective case note review was carried out for patients undergoing microtibial embolectomy from 1990 to 1999. Data collected included the causes and degree of ischaemia, additional procedures required, vessel patency, limb salvage and complications encountered. RESULTS: twenty-two limbs underwent exploration of the crural/pedal vessels with ankle level arteriotomies under local anaesthetic in 12 cases, general anaesthetic in nine and epidural in one. The causes of ischaemia were cardiac emboli (8), "trash foot" (7), emboli from aortic and popliteal aneurysms (3) and thrombotic occlusion of crural vessels (4). The vessel patency rate was 69% and limb salvage rate 62% (13/21) up to 5-years follow-up. Six of the seven cases with "trash foot" were salvaged while one required an amputation at 3-months post-operatively. The 30-day mortality was 22% (5/22). CONCLUSIONS: microtibial embolectomy is effective in acute occlusion of the crural/pedal arteries including cases of "trash foot", offering limb salvage to a worthwhile proportion of cases.

Aged↗
PubMed2003

The efficacy of aspirin in patients undergoing infra-inguinal bypass and identification of high risk patients.

AIM: Infrainguinal bypass is an effective treatment for critical lower limb ischemia but up to 1/3 of these grafts will occlude within the 1st year. The aim of this audit was to evaluate the efficacy of aspirin in maintaining graft patency and also improving patient survival. METHODS: In a single audited year (1997) 125 bypasses were carried out. Seventy-nine were on aspirin, 34 on no treatment and 12 were on other agents and hence excluded from analysis. The indication for surgery was critical ischaemia in 101 and disabling claudication in 12. Autologous vein was used in 104 and prosthetic grafts in 9. RESULTS: The overall 2-year primary graft patency, secondary graft patency and limb salvage were 50%, 71% and 83%, respectively. The 2-year secondary patency in patients with or without aspirin was 73% and 64%, respectively (p<0.12-log rank test). The corresponding patient survival from vascular death in the 2 groups was 73% and 70% (p<0.67-log rank test). Crural/ pedal bypass (51/75 on aspirin) and smoking (51/61 on aspirin) were independent risk factors for graft failure and vascular death respectively whilst those with a previous myocardial infarct (21/28 on aspirin) reached significance in univariate analysis only (p< 0.03). CONCLUSION: Aspirin was not a significant factor in preventing graft failure or vascular death in patients undergoing bypass for critical limb ischemia. Dual therapy with other antiplatelet agents needs to be considered in such patients particularly those undergoing crural/pedal bypass, smokers and those with a history of previous myocardial infarction.

Adult↗
PubMed2002

Splanchnic oxygenation in patients undergoing abdominal aortic aneurysm repair and volume expansion with eloHAES.

BACKGROUND: Gastric intramucosal pH (pHi), a surrogate marker of splanchnic oxygenation, falls following abdominal aortic aneurysm surgery. AIM: To investigate the effects of volume expansion with hydroxyethyl starch (eloHAES) on splanchnic perfusion compared to another colloid such as gelofusine. PATIENTS AND METHODS: Twenty-two consecutive patients undergoing AAA repair were randomised to receive either eloHAES or gelofusine as plasma expanders. Tissue oxygenation was monitored (10 gelofusine and 12 eloHAES) indirectly by measuring pHi using a nasogastric tonometer. RESULTS: Compared to the eloHAES group, the fall in pHi was significantly greater in the gelofusine group at clamp release (7.29 vs 7.33, P=0.003) and at 4 h following clamp release (7.29 vs 7.33, P=0.03). There was a good inverse correlation between the lowest pHi and the peak serum interleukin-6 (r(s)= -0.47, P=0.03). By multivariate analysis, the only factor that influenced the pHi was the type of colloid used (F=5.54, P=0.005). The eloHAES treated patients required significantly less colloid on the first postoperative day (3175 +/- 175 vs 4065 +/- 269 ml, P=0.01). CONCLUSION: In patients undergoing abdominal aortic aneurysm repair, plasma expansion with eloHAES improves microvascular perfusion and splanchnic oxygenation.

Aged↗
PubMed2000

Association of sex with patency of femorodistal bypass grafts.

OBJECTIVE: There is evidence for superior patency in infra-inguinal bypass procedures in men compared to women. A large, prospectively planned series was investigated in order to confirm this finding and to determine the origin of this difference in outcome. METHODS: Patients underwent femorodistal bypass surgery and a prospectively planned 12-month follow-up. Outcomes in male and female patients were compared and investigated for associations with characteristics of the patients and the surgical procedures. RESULTS: A total of 517 patients received femorodistal bypass grafts, including 424 vein grafts and 93 prosthetic and vein-prosthetic composite grafts. Patency was confirmed to be higher in male than in female patients (56% vs. 42%, p=0.005). Fewer male patients received prosthetic or composite grafts (21% vs. 33%, p=0.005), but the difference in patency was evident only in patients receiving vein grafts. Female patients were smaller, included fewer smokers (p<0.001) and had worse symptoms (p=0.03), but none of these characteristics explained the difference in outcome. Patency in vein grafts was associated with graft diameter (p=0.004), but graft diameter was not significantly associated with sex (p=0.09) or with body size. CONCLUSIONS: It was confirmed that patency of femorodistal bypasses is significantly higher in males than females. None of the factors investigated here explain this difference, but the greater use of prosthetic and composite grafts in female patients suggests that poorer vein quality should be investigated as a possible source of the inferior outcome in female patients.

Aged↗
PubMed2000

Incidence of stenoses in femorodistal bypass vein grafts in a multicentre study.

OBJECTIVES: To establish the incidence of graft stenosis in a large population of patients undergoing femorodistal bypass procedures and to investigate the differences in incidence between individual surgical centres and other subpopulations. PATIENTS AND METHODS: A total of 277 patients with femorodistal bypasses underwent duplex scanning of vein grafts for 12 months for the detection of graft stenoses. A standard definition of a significant stenosis was used in all twenty participating centres. RESULTS: Overall stenosis rate was 27%. Stenoses were more common in composite vein grafts (43%) than in single segment vein grafts (25%) p=0.05. Stenoses were more common in female patients (38%) than males (22%) p=0.02. Stenosis rates in individual centres entering more than 20 patients varied from 9% to 56%. In a multiple regression analysis only aspirin use, sex and centre were significant factors predicting the likelihood of graft stenosis. CONCLUSION: Female patients, those taking aspirin and patients with composite vein grafts appear to be more at risk of graft stenosis, but this does not fully explain wide variations in the incidence of stenoses reported by individual centres.

Adult↗
PubMed1999

Free jejunal patch flaps in oral and oro-pharyngeal reconstruction.

Free jejunum has been commonly tubed to provide a reconstructive pharyngeal conduit following pharyngolaryngectomy. It is also common practice to repair small oral and oro-pharyngeal defects with skin-lined flaps i.e. radial free forearm or pectoralis major myocutaneous flap. Free jejunal patch flaps can provide cover for large defects, secrete mucus, tolerate radiotherapy well and do not contract. The operation is associated with a low morbidity and early return of swallowing is feasible. Here we describe the functional results of free jejunal patch flap reconstruction of extensive oral and oro-pharyngeal defects.

Adult↗
PubMed1999

Relationship of femorodistal bypass patency to clinical outcome. Iloprost Bypass International Study Group.

OBJECTIVE: To investigate the relationship between bypass patency, limb survival and clinical symptoms after femorodistal bypass procedures. DESIGN: Multicentre, prospectively planned 12-month postoperative follow-up. PATIENTS AND METHODS: Five hundred and seventeen patients undergoing femorodistal bypass surgery for severe ischaemia. Clinical symptoms, bypass patency were recorded at regular intervals up to 12 months postoperatively. RESULTS: Complete follow-up data was obtained on 498 patients (96%). Fifty-six (17%) of the 341 patients with patent bypasses had either rest pain or ulcers or had undergone major amputation at 12 months. Of the 167 patients with an occluded bypass, 22 patients (13%) had improved clinical symptoms and a total of 59 patients (35%) had avoided major amputation at 12 months. The clinical outcome for patients classified preoperatively as Fontaine stage IV was significantly worse than for those in stage III preoperatively despite similar bypass patency rates. CONCLUSIONS: There is a fair correlation between technical and clinical outcome after femorodistal bypass surgery at 12 months, but there are significant numbers of patients with occluded bypasses who have a good clinical outcome and of patients with patent bypasses who have a poor clinical outcome. The reporting of symptoms in addition to bypass patency would aid the interpretation of surgical results.

Adult↗
PubMed1997

Local anaesthetic for lower-limb revascularization in high-risk patients.

BACKGROUND: A few patients with critical limb ischaemia are believed to be too unfit for an attempt at revascularization using conventional anaesthesia. METHODS: A retrospective analysis was undertaken of 46 revascularization procedures performed in high-risk patients for critical limb ischaemia between 1989 and 1995, in which local anaesthetic techniques were utilized in preference to general or spinal anaesthesia. RESULTS: Cumulative survival rates at 6, 12 and 24 months were 67, 57 and 51 per cent. Primary patency rates were 77 per cent at 6 months, 67 per cent at 12 months and 53 per cent at 24 months, with associated limb salvage rates of 87, 87 and 79 per cent. CONCLUSION: Selective use of local anaesthetic techniques extends the benefits of limb salvage to patients considered unfit for conventional anaesthesia.

Aged↗
PubMed1994

Pharmacological reduction of the systemically damaging effects of local ischaemia.

Many patients with intermittent claudication are encouraged to exercise. However, transient exercise-induced muscle ischaemia results in systemic vascular endothelial injury associated with increased vascular permeability manifest as an increase in urinary albumin excretion. Repetitive systemic vascular endothelial injury leads to accelerated atherogenesis and may explain the high cardiovascular mortality rate of claudicants. Oxpentifylline, a haemorheological agent, has recently been shown to prevent vascular endothelial injury in animal models. A double-blind, placebo-controlled, cross-over trial was undertaken to determine the effect of oxpentifylline on exercise-induced systemic vascular endothelial injury in 20 claudicants. Urinary albumin, expressed as a creatinine ratio (ACR), was measured before and 1 and 2 hours after standardised exercise following 1 week treatment with either active drug or placebo. Oxpentifylline reduced the median (range) 1 hour post exercise increase in ACR from 0.35 (-0.46-12.72) to 0.02 (-6.00-14.10) mg/mmol. (p = 0.030, z = 2.2 Wilcoxon rank sign test). These results confirm that local ischaemia is associated with a potentially deleterious systemic effect and that it may be possible to attenuate this pharmacologically. The clinical significance of this is yet to be determined.

Aged↗
PubMed1994

Falsely elevated ankle pressures in severe leg ischaemia: the pole test--an alternative approach.

Ankle-branchial pressure indices (ABPIs), measured by sphygmomanometer and Doppler probe, are an accepted index of chronic leg ischaemia. However, tibial artery sclerosis or calcification decreases compliance, producing falsely elevated cuff occlusion pressures. Arterial cannulation is invasive and impractical, but by elevating the foot and measuring the height at which the Doppler signal disappears, ankle systolic pressure in mmHg can be derived. Using an 8MHz Doppler apparatus and calibrated pole, ankle systolic pressures measured by sphygmomanometer and elevation were compared in 49 severely ischaemic legs (40 patients). ABPIs were derived by dividing ankle systolic pressure by brachial pressure. Median (interquartile range) ABPI assessed by sphygmomanometry was 0.46 (0.35-0.56). Median ABPI measured by leg elevation was significantly lower at 0.21 (0.14-0.30), p < 0.0001, Wilcoxon. In 20 patients undergoing in situ vein bypass grafting, direct transducer-derived pressure measurements were obtained. Median ABPI for this method was 0.15 (0.11-0.27). No significant difference was found when compared with ABPIs derived by elevation, median 0.2 (0.13-0.31), p = 0.324, however median ABPI measured by sphygmomanometry was significantly higher at 0.37 (0.27-0.6), p = 0.0008. Correlation of elevation with transducer-assessed pressure measurements (r = 0.88) was closer than with cuff-derived measurements (r = 0.69). Pressures derived by leg elevation provide a more accurate index of severe leg ischaemia than sphygmomanometry, although the technique is limited to assessing pressures of less than approximately 60 mmHg. Falsely elevated ABPIs may underestimate the extent of disease in patients assessed for vascular reconstruction.

Aged↗
PubMed1993

Intermittent claudication incites systemic neutrophil activation and increased vascular permeability.

Reperfusion following severe ischaemia incites a systemic response involving neutrophil activation and vascular injury. Recent work suggests that intermittent claudication may also be capable of inducing similar changes, reversible by revascularization. This observation may have implications for the treatment of claudication and explain the high associated cardiovascular mortality. This hypothesis was investigated using an in vivo model. Rats underwent repeated hindlimb stimulation after common iliac artery ligation. Intravital fluorescence microscopy was used to observe postcapillary venules of the tibialis anterior muscle in the hindlimb. This revealed a bilateral increase in leucocyte-endothelial adhesion and vascular permeability to albumin after unilateral subtotal ischaemia and muscle stimulation, associated with increased urinary albumin excretion. These results provide further evidence supporting the association of intermittent claudication with potentially deleterious systemic manifestations.

Animals↗
PubMed1993

Adjuvant prostanoid treatment during femorodistal reconstruction.

A prospective randomized placebo-controlled trial was conducted to determine the effects of the stable prostacyclin analogue iloprost on early graft patency and hemodynamic parameters during femorodistal reconstruction for critical leg ischemia. Peripheral resistance and graft blood flow were measured using an operative Doppler flowmeter and graft pressure transducer. Postoperative graft surveillance was continued at 1-month and then at 3-month intervals by duplex Doppler ultrasonography, measurement of ankle-brachial pressure indices, and intravenous digital subtraction angiography when indicated. In patients receiving 3000 ng of iloprost (n = 45) infused into the graft on completion there was an immediate mean decrease in peripheral resistance of 44% that persisted to skin closure in comparison with controls (n = 38) in whom no such decrease in resistance occurred (p < 0.001, Wilcoxon test). During the same period, mean graft blood flow increased in iloprost-treated patients by 74.5% compared with controls in whom there was a 6% increase in flow (p < 0.001). Primary cumulative patencies at 1 month were significantly higher in iloprost-treated grafts, 98% compared to 83% for controls (p < 0.05, log-rank test). Cumulative primary patencies at 1 year and secondary patencies at 1 month and 1 year were also greater in the iloprost-treated group (67%, 98%, and 87.6%, respectively) compared to controls (65%, 86%, and 79.3%, respectively), but these did not achieve statistical significance. A single bolus infusion of iloprost has prolonged beneficial effects on graft blood flow and peripheral resistance during femorodistal reconstruction. This is reflected by improved early primary graft patencies.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Postoperative chylothorax: a case for recycling?

Postoperative chylothorax in a patient who was rapidly deteriorating despite conservative treatment is described. A system of recycling chyle from the pleural space through a filter and pump into the subclavian vein is discussed. The history of reinfusion of chyle is reviewed.

Aged↗