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Biomedical subjects

L T Lim

Publications and source records attributed to L T Lim.

At least 19 recordsLinked to original sources

Therapeutic deep lamellar keratoplasty for corneal perforations.

OBJECTIVES/AIMS: Corneal perforation can be potentially blinding unless the integrity of the globe is restored quickly. Although penetrating keratoplasty (PK) may achieve this, it carries a high risk of endothelial rejection in inflamed eyes. Deep lamellar keratoplasty (DLK) may be an alternative option to PK in such eyes owing to its potential for a lower incidence of rejection. We report the efficacy of DLK in patients with corneal perforations. PATIENTS AND METHODS: Four patients underwent layer-by-layer DLK for noninfective corneal perforation, after measures such as the use of a bandage contact lens, tissue adhesive, and conjunctival pedicle flap had failed. The preoperative visual acuity was hand movements in one patient, 1/60 in two, and 6/60 in one. All four had iris incarcerated within the corneal perforations. SF6 gas (three patients) and air (one patient) were injected into the anterior chamber at the end of surgery. RESULTS: The integrity of the globe was restored in all four patients with an improvement in visual acuity (6/60 in one and 6/36 or better in three). The mean follow-up time was 7 months. All four patients had clear corneas 3 months postoperatively, apart from the area of the original perforation. There was no recurrence of ulceration or perforation. CONCLUSION: DLK is a safe and effective therapeutic measure in the management of patients with corneal perforations acting to preserve the integrity of the globe and restore vision.

Adolescent↗

Management and outcome of sight-threatening diabetic retinopathy in pregnancy.

AIMS: To report the management and outcomes of sight-threatening diabetic retinopathy in pregnancy. METHODS: A retrospective review of 8 diabetic females who developed pregnancy related sight-threatening diabetic retinopathy requiring treatment over a 12-year period. RESULTS: In total, 16 eyes of eight patients were included in this series. The mean age of the patients at presentation was 30.75 years +/-3.8 SD and the mean duration of diabetes was 21.0 years +/-5.1 SD. The mean follow-up period was 46.75 months +/-47.2 SD. A total of 87.5% of patients showed progression of diabetic retinopathy during pregnancy, 71% of which were in the sight-threatening proliferative category. In the postpartum period, 81% of patients continued to progress to proliferative diabetic retinopathy, requiring panretinal photocoagulation and multiple other surgical procedures. In all, 69% of eyes retained visual acuity equal to or better than 0.3 logMAR units (6/12). CONCLUSION: Sight-threatening diabetic retinopathy in pregnancy is a rare disease, but it can have devastating consequences for mother and child. Laser photocoagulation should be considered for pregnant women with severe preproliferative diabetic retinopathy. Proliferative diabetic retinopathy may not regress postpartum. Close followup should be extended in the postpartum period in this group of patients until the retinopathy is stabilised. The presence of combined rhegmatogenous and tractional retinal detachment and neovascular glaucoma were associated with the worst outcome.

Adult↗

Quantification of the surface morphologies of lactose carriers and their effect on the in vitro deposition of salbutamol sulphate.

Application of the scanning probe microscopy technique for quantitative measurement of the surface roughness of lactose carriers was evaluated. The roughness values of four different lactose carriers were related to the in vitro deposition results of the drug, salbutamol sulphate. The rugosity values of the lactose carriers were represented by Ra values which were in the order of DCL-40>DCL-11>lactose 325M>lactose 200 M. In vitro deposition results using a twin impinger showed that rougher carrier surfaces generally allowed more drug particles to be emitted from the capsules and inhaler but the availability of the drug to stage 2 was reduced, as detachment of drug particles from the carrier surfaces was more hindered. There was an optimum Ra value for greater delivery of the drug particles to stage 2 of the twin impinger. A balance between adherence and detachment of the drug from the carrier surface was needed in order to optimize the delivery of a drug to the desired target sites using a dry powder inhaler.

Adrenergic beta-Agonists↗

Results of venous reconstruction after civilian vascular trauma.

The treatment of venous injuries remains controversial. In an attempt to evaluate the results of current management of venous injuries, we retrospectively reviewed our experience between 1979 and 1984. During this period 142 patients had sustained injuries to 158 veins in the neck (31 patients), abdomen (45 patients), upper extremity (20 patients), and lower extremity (62 patients). Overall, 90 venous injuries (61%) were repaired, including 83% of caval and iliac vein injuries and 90% of injuries to the common femoral, superficial femoral, and popliteal veins. There was no morbidity after repair of 73 major veins. Morbidity occurred in four of 11 patients after ligation of major veins (edema in two patients and above-knee amputation in two others). Both ligation (N = 51) and repair (N = 17) of lesser veins (jugular, brachial, profunda femoral, tibial, and minor abdominal veins) resulted in no morbidity. Overall mortality was 6% with all deaths occurring in patients with abdominal venous trauma. These data indicate that repair of venous injuries can be performed without morbidity and that minor veins can be ligated without adverse sequelae. However, in view of the morbidity associated with ligation of major veins, efforts to restore flow to these injured vessels appear appropriate unless contraindicated by life-threatening injury.

Adolescent↗

Improved results in the treatment of civilian vascular injuries associated with fractures and dislocations.

Patients with vascular injuries associated with fractures or dislocations of the extremities were managed according to a standard protocol, which included the liberal use of preoperative arteriography, early fasciotomy when indicated, individualization of timing and type of orthopedic procedures, arterial reconstruction primarily with interposition reversed saphenous vein grafts, repair of major venous injuries, routine completion arteriography, and regular postoperative monitoring of Doppler-derived ankle/brachial indices. Adherence to these principles led to a limb salvage rate of 97% in 38 patients with such injuries.

Adolescent↗

The necessity of mandatory exploration of penetrating zone II neck injuries.

To reevaluate the validity of our policy of mandatory surgical exploration of penetrating zone II neck injuries, the charts of 110 patients who underwent surgical exploration for such injuries were reviewed. Fifty-three percent of the patients had normal findings at exploration, whereas 33% had injuries involving vascular structures of the neck and 14% had nonvascular injuries. Injuries were not suspected on clinical grounds preoperatively in 23% of the patients in whom surgical exploration revealed injury. The injuries most likely to escape preoperative diagnosis were isolated venous injuries and isolated pharyngoesophageal injuries. Arteriography yielded false-negative results in two arterial injuries. No deaths and only a 5% incidence of minor complications occurred in the group with no injuries detected at exploration. We conclude that surgical exploration of penetrating zone II neck injuries is safe and appropriate.

Adolescent↗

Optimal limb salvage in penetrating civilian vascular trauma.

To evaluate current treatment of peripheral vascular trauma, we reviewed our recent experience with noniatrogenic penetrating vascular injuries of the extremities. Between 1979 and 1984, 139 patients sustained 204 vascular injuries inflicted by single gunshots (64%), stabbings (24%), and shotguns (12%). Eighty-four percent of patients underwent preoperative arteriography, which revealed occult arterial injury in 13 patients (9%). Compartmental hypertension necessitated fasciotomy in 19% of patients and was required more often after combined arterial and venous injuries (29%) than after isolated arterial injury (14%). Arterial continuity was restored by interposition grafting with reversed saphenous vein (62%), end-to-end anastomosis (19%), vein patch angioplasty (8%), or primary repair (4%). After arterial repair, completion angiography detected the need for revision in 8% of patients. Arterial ligation was performed in 7% of injuries and was only used in the treatment of tibial and distal profunda femoris injuries. Forty-five percent of patients sustained concomitant venous injury; 64% of all venous injuries and 90% of femoropopliteal venous injuries were repaired. No deaths occurred, and a single patient required amputation. We conclude that a protocol of preoperative arteriography, liberal. use of fasciotomy, frequent use of autologous interposition grafts, repair of major venous injuries, and routine use of completion arteriography can result in limb salvage rates that approach 100% after penetrating vascular trauma to the extremities.

Adolescent↗

Peripheral vascular trauma from close-range shotgun injuries.

This report summarizes an eight-year experience (1976 to 1983) with 49 close-range shotgun blasts with associated major vascular injuries seen in a large urban hospital. Injuries to the upper extremity (40%), lower extremity (56%), and neck (4%) were seen. A high frequency of associated deep venous injury (82%), nerve injury (37%), fracture (33%), massive soft-tissue loss (43%), and compartmental hypertension (39%) was observed. There were no deaths in this series, and the limb salvage rate was 96%. Neither patient with multiple carotid artery injuries suffered a neurologic deficit. We attribute our success in the management of these complex injuries to rapid fracture immobilization, early and aggressive use of fasciotomy, adequate débridement of devitalized tissue, repair of deep venous injuries, arterial repair with autogenous tissue, and extra-anatomic bypass grafting in selected cases.

Adolescent↗

The treatment of cerebral ischemia by external carotid artery revascularization.

Thirteen patients with internal carotid artery occlusion and symptomatic external carotid artery stenosis underwent external carotid artery revascularization by means of endarterectomy (n = 10) or subclavian artery--external carotid artery bypass (n = 3). All patients but one were followed up, for five to 46 months (mean, 20 months). There were no operative deaths or complications and no late strokes. One patient (7.7%) required early extracranial-intracranial (EC-IC) bypass for failure of the external carotid artery endarterectomy to relieve the initial symptoms. All remaining patients were completely (n = 9) or partially (n = 2) relieved of symptoms, and EC-IC bypass was not required. There were no criteria identified by either oculopneumoplethysmography or angiography that could reliably predict the need for subsequent EC-IC bypass. Ninety-two percent of the patients were adequately treated with external carotid artery revascularization alone, suggesting that subsequent EC-IC bypass is seldom required in patients with ipsilateral internal carotid artery occlusion and external carotid artery stenosis.

Aged↗

Elimination of iatrogenic impotence and improvement of sexual function after aortoiliac revascularization.

One hundred ten men who underwent revascularization for aortoiliac occlusive disease by either aortic reconstruction (n = 66), crossover femorofemoral bypass (n = 38), or axillofemoral bypass (n = 6) were examined with regard to preoperative and postoperative sexual function. Aortic reconstructions were performed using a nerve-sparing technique, and special emphasis was placed on preservation or improvement of pelvic blood supply. Thirty patients (27%) were impotent preoperatively and postoperatively, 67 patients (61%) had normal sexual function preoperatively and postoperatively, and 13 patients (12%) who were impotent preoperatively regained sexual function as a result of revascularization, indicating that 30% (13/43) of all patients with preoperative impotence regained sexual function. No patient with normal preoperative sexual function was impotent postoperatively. Nerve-sparing aortic dissections, attention to preservation or improvement of pelvic blood flow, and, when appropriate, extra-anatomic bypass are essential in the preservation or improvement of sexual function after aortoiliac revascularization.

Adult↗

Intraoperative assessment of limb revascularization by Doppler-derived segmental blood pressure measurements.

Prompt recognition and correction of technical errors in vascular procedures in the lower extremities decreases patient morbidity and improves the chances for successful revascularization. A simple, versatile technique for intraoperative hemodynamic assessment of lower extremity revascularization procedures is described. Salient features include ability to detect and correct technical errors without reoperation and its associated morbidity, use of commonly available, inexpensive equipment, and ease of performance without involvement of either specifically trained or inexperienced personnel.

Blood Pressure Determination↗

Anatomic and hemodynamic evaluation of percutaneous transluminal angioplasty.

Of 34 balloon angioplasties of the lower extremity performed during a two year period, 29 were observed for three to 21 months. Hemodynamic measurements were performed preangioplasty, immediately postangioplasty and at three month intervals thereafter. Immediately, postangioplasty arteriograms were performed upon all patients. Late follow-up arteriograms were obtained for selected patients. Immediate anatomic success was achieved in 93 per cent of procedures, but early hemodynamic improvement occurred in only 62 per cent of the angioplasty procedures. At a mean follow-up time of nine months, continued success was noted in only 48 per cent of the procedures. Late failure with iliac artery procedures was demonstrated in only 18 per cent of the patients, while, in femoropopliteal angioplasty, late failure occurred in 50 per cent of the procedures. The results of this study and of others indicate that femoropopliteal balloon angioplasty in not a durable procedure. The durability of iliac artery angioplasty requires further evaluation.

Angiography↗

The effect of carotid siphon stenosis on stroke rate, death, and relief of symptoms following elective carotid endarterectomy.

It has been suggested that carotid endarterectomy for carotid bifurcation disease may be contraindicated in the presence of carotid siphon lesions. This study was undertaken to assess any difference in stroke rate, mortality, or relief of symptoms in patients with and without such "tandem" lesions following elective carotid endarterectomy. Ninety-one bifurcation endarterectomies were performed in 79 patients. The patients were divided into two groups. Group I (44 patients, 47 endarterectomies) had carotid bifurcation stenosis only; group I (35 patients, 44 endarterectomies) had siphon stenosis plus bifurcation stenosis. All patients in both groups who were symptomatic before operation were relieved of their symptoms. In group I there were no intraoperative or perioperative strokes, four late strokes (8.7%), one operate death (2.1%), and no late deaths. Group II patients had two intraoperative strokes (4.5%), three perioperative strokes (6.8%), two late strokes (5.1%), four operative deaths (9.1%), and three late deaths (7.5%). Eighteen of the 35 patients in group II had a greater degree of carotid siphon stenosis than bifurcation stenosis. In this subgroup, there was one operative stroke (5.6%), only perioperative stroke (5.6%), one late stroke (5.9%), one postoperative death (5.6%), and one late death (5.6%). None of these differences were statistically significant. Relief of symptoms was the same in patients with and without tandem carotid lesions, and there was no significantly increased risk of stroke or death following bifurcation endarterectomy in patients with tandem carotid lesions.

Adult↗

Popliteal artery trauma. 31 consecutive cases without amputation.

Injury to the popliteal artery is the most common cause of amputation in injured extremities. A six-year experience (1974-1979) at Cook County Hospital, Chicago, involved 31 popliteal artery injuries without amputation. Penetrating trauma was the most frequent cause of injury; however, a considerable number of blunt trauma injuries with fractures and dislocations were also present. Prolonged ischemic time was not a deterrent to successful vascular reconstruction. The recognition of compartmental hypertension and performance of fasciotomy before vascular repair were credited as major factors in our success. The use of interposition saphenous vein graft in the arterial reconstruction, repair of concomitant popliteal vein injuries, initial bone fixation of fractures with external fixators, and the performance of intraoperative arteriography were all important steps taken to ensure a 100% limb salvage.

Adolescent↗

Management of complex vascular injuries to the extremities.

Complex vascular injuries to the extremities are challenging and, to this day, continue to cause significant morbidity and tax the ingenuity of the vascular surgeon. we have presented complicating factors and conditions that may jeopardize a successful outcome. Distal ischemia and limb loss may be caused by conditions other than arterial injury. Venous repair for major venous injury, decompression fasciotomy in compartmental hypertension, early recognition and management of associated vascular injuries in fractures and dislocations, sensible use of arteriography and venography, and prevention of postoperative wound infection by radical debridement and adequate wound coverage for close-range shotgun wounds and replanted limbs are some of the important features that will aid in successful efforts to preserve the anatomy and function of the traumatized limb.

Adolescent↗

Jejunoaortic fistula from ingested seamstress needle.

A 27-year-old man was evaluated for sudden onset of massive hematemesis and hematochezia. A bleeding site was not seen on esophagogastroduodenoscopy. There was little blood in the stomach, which suggested that the bleeding site was below the ligament of Treitz. Angiography demonstrated the presence of an intra-aortic metallic foreign body that resembled a sewing needle. At operation, a chronic jejunoaortic fistula that contained the sewing needle was found and repaired. The patient had no recollection of having swallowed the needle, and it is presumed that he ingested it in infancy. He had an uneventful recovery.

Adult↗

The therapy of peripheral vascular ulcers--surgical management.

Venous ulcers are a common malady of the civilized world. The etiology and its pathogenesis has been presented for a better understanding of its appropriate therapy. A conservative and surgical approach is necessary for effective treatment, of which the final goal is to reduce ambulatory venous hypertension and the prevention of venous ulcer formation. An effective regime of elastic support, periodic leg elevation and surgery for incompetent perforators is highly rewarding. The good results in the use of dextranomer for highly exudative ulcers have also been presented as another adjunct in the local care of venous ulcers.

Humans↗