Management of peritoneal tear during endoscopic extraperitoneal inguinal hernioplasty

BACKGROUND

Peritoneal tear during endoscopic extraperitoneal inguinal hernioplasty (TEP) results in pneumoperitoneum and loss of extraperitoneal space. To avoid bowel adhesions, internal herniation, and mesh migration, closure of the peritoneal opening is preferred. The present study was conducted to evaluate the efficacy of various operative techniques for the closure of peritoneal laceration.

METHODS

Between April 2000 and May 2001, 100 consecutive patients undergoing 123 TEPs were recruited for the present study. The incidence of peritoneal tear and techniques for the closure of peritoneal opening were documented. Operative time and postoperative morbidity were compared among groups for which different closure methods of peritoneal laceration were used.

RESULTS

The incidence of peritoneal tear was 47%. The mean operative times of unilateral TEPs with and without peritoneal laceration were 66 min and 53 min, respectively (p<0.05). Techniques for the closure of the peritoneal opening included endoscopic stapling (n = 12), endoscopic suturing (n = 14), and pretied suture loop ligation (n = 21). The mean operative times for unilateral TEPs with endoscopic stapling, pretied suture loop ligation, and endoscopic suturing of peritoneal tear were 53, 64, and 82 min, respectively (p<0.05). Comparison of postoperative morbidity showed no significant differences among the three groups.

CONCLUSION

Peritoneal tear is a frequent and challenging intraoperative event during TEP. Its occurrence significantly prolongs the length of operation. Endoscopic stapling and pretied suture loop ligation are safe and quick techniques for the closure of peritoneal tear during TEP.

Prophylaxis of radiation-associated mucositis in conventionally treated patients with head and neck cancer: a double-blind, phase III, randomized, controlled trial evaluating the clinical efficacy of an antimicrobial lozenge using a validated mucositis scoring system

PURPOSE

Mucositis occurs in almost all patients treated with radiotherapy for head and neck cancer. The aim of this multicenter, double-blind, prospective, randomized trial was to evaluate the clinical efficacy of an economically viable antimicrobial lozenge (bacitracin, clotrimazole, and gentamicin [BcoG]) in the alleviation of radiation-induced mucositis in patients with head and neck cancer.

PATIENTS AND METHODS

One hundred thirty-seven eligible patients were randomized to treatment with either antimicrobial lozenge (69 patients) or placebo lozenge (68 patients). The primary end point of the study was the time to development of severe mucositis from the start of radiotherapy. Secondary end points included severity and duration of mucositis, pain measurement, radiation therapy interruption, and quality of life. Mucositis was scored using a validated mucositis scoring system.

RESULTS

Toxicity profiles were similar between the two arms of the study. The median time to development of severe mucositis from the start of radiotherapy was 3.61 weeks on BCoG and 3.96 weeks on placebo (P =.61). There were no statistically significant differences between the arms in the extent of severe mucositis as measured by physician, in oral toxicities as recorded by patients, or in radiotherapy delays.

CONCLUSION

This study was conducted on the basis of a pilot study that demonstrated the BCoG lozenge to be tolerable and microbiologically efficacious. A validated mucositis scoring system was used. However, in this group of patients treated with conventional radiotherapy, the lozenge did not impact significantly on the severity of mucositis. Whether such a lozenge would be beneficial in treatment situations where rate of severe mucositis is higher (ie, in patients treated with unconventional fractionation or with concomitant chemotherapy) is unknown.

Epigastric hernia and its etiology

BACKGROUND

Controversies still prevail as to how exactly epigastric hernia occurs. Both the vascular lacunae hypothesis and the tendinous fibre decussation hypothesis have proved to be widely accepted as possible explanations for the etiology.

PATIENT

We present a patient who suffered from early-onset epigastric hernia.

CONCLUSIONS

We believe the identification of the ligamentum teres and its accompanying vessel at its fascial defect supports the vascular lacunae hypothesis. However, to further our understanding, biopsy of the linea alba in patients with epigastric hernias is indicated.

Distinct regional expression of SNARE proteins in the feline oesophagus

Abstract Soluble N-ethylmaleimide-sensitive factors attachment protein receptors (SNAREs), initially found to mediate membrane fusion, have now been shown to also bind and regulate a number of membrane ion channels in neurones and neuroendocrine cells. We recently reported that the SNARE protein SNAP-25 regulates Ca(2+)- activated (K(Ca)) and delays rectifier K(+) channels (K(V)) in oesophageal smooth muscle cells. This raised the possibility that cognate and other SNARE proteins could also be present in the oesophageal smooth muscle cell to regulate these and other functions. Circular muscle tissue sections and single freshly isolated muscle cells from the oesophageal body circular and longitudinal layers, and from lower oesophageal sphincter clasp and sling regions were studied. The subcellular location of SNAP-23, SNAP-25, syntaxins 1 to 4, and vesicle-associated membrane protein (VAMP)-2 were explored using a laser scanning confocal imaging system. Feline oesophageal smooth muscle of all regions examined demonstrated the presence of SNAP-23, SNAP-25, syntaxins 1 to 4, and VAMP-2 on the plasma membrane. The intensity of these syntaxins and SNAP-25/-23 proteins varied between the different muscle groups of the oesophagus. In some regions, some SNARE proteins were also noted in the muscle cell cytoplasm. No differential expression was found for VAMP-2. The differential expression of SNAP-25 and its regulation of K(+) channels indicate the important role of SNAP-25 in regulating the distinct membrane excitability and contractility along the smooth muscle of the oesophagus. This is further contributed by its interactions with the cognate syntaxins, which are also differentially expressed in the muscle groups of the oesophageal body and lower oesophageal sphincter (LOS). These SNARE proteins probably have other functions in the smooth muscle cell, such as regulating vesicular transport processes.

Transitions in laparoscopic cholecystectomy: the impact of ambulatory surgery

BACKGROUND

Ambulatory laparoscopic cholecystectomy is a common practice in the United States, but its development remains slow in most other countries. The objective of the current study was to report the impact of ambulatory surgery on the practice of laparoscopic cholecystectomy in a major teaching hospital since the inception of the service.

METHODS

The hospital database of patients who underwent cholecystectomies for benign hepatobiliary pathologies was reviewed between January 1993 and December 1999. Changes in the practice of laparoscopic cholecystectomy and the length of hospital stay were analyzed. Clinical characteristics of the ambulatory and inpatient groups were compared.

RESULTS

Of 2,891 laparoscopic cholecystectomies involved in the current study, 888 (31%) were performed as day cases, and 2,003 (69%) were performed as inpatient laparoscopic cholecystectomies. The annual number of ambulatory laparoscopic cholecystectomies increased from 3 (0.6%) in 1993 to 212 (48%) in 1997. This was followed by a plateau in the next 3 years. The ambulatory group comprised a significantly higher prevalence of young women (87%) who underwent surgery mainly for biliary colic (88%).

CONCLUSIONS

The current study demonstrated a net trend toward ambulatory laparoscopic cholecystectomy and a shorter length of hospital stay. Almost half of our patients with gallstone disease currently are using the ambulatory laparoscopic cholecystectomy service, with young women constituting the majority. We predict that ambulatory laparoscopic cholecystectomy heralds the wave of the future, and our experience may serve as a blueprint for other institutions wishing to embark on this journey.

Extrahepatic portal vein aneurysm: a case report and review of the literature

Portal vein aneurysm is a rare clinical entity with only 42 published cases in the English literature. We present a 30-yr old woman who was incidentally diagnosed with an extrahepatic portal vein aneurysm during the investigation for dyspepsia. Expectant management with regular follow-up and surveillance imaging was adopted. This pathology is increasingly encountered with the frequent use of radiological imaging modalities in the work-up of abdominal disorders. Etiology, clinical significance and management strategies for extrahepatic portal vein aneurysms are discussed.

A prospective trial of analgesia following endoscopic totally extraperitoneal (TEP) inguinal hernioplasty

BACKGROUND

The extraperitoneal instillation of bupivacaine has been shown to be superior to the use of a placebo for postoperative analgesia following endoscopic extraperitoneal inguinal hernioplasty. The objective of the present study was to compare the efficacy of postoperative analgesia by local wound infiltration to instillation of the extraperitoneal space with bupivacaine.

METHODS

Between 1 September 1999 and 2 June 2000, a total of 100 patients who underwent unilateral endoscopic extraperitoneal inguinal hernioplasties were recruited to receive either local wound infiltration with 10 ml of 0.5% bupivacaine (group I, n = 50) or instillation of the extraperitoneal space with 40 ml of 0.25% bupivacaine after mesh placement (group II, n = 50). Daily postoperative pain was assessed by visual analogue pain score on a scale from 0 to 10 at rest and upon coughing. Total amount of oral analgesic consumed and clinical outcomes of the two groups were compared.

RESULTS

A comparison of daily pain scores of the two groups at rest and upon coughing showed no significant difference (p = ns). The mean number of oral analgesic tablets consumed were 3.2 +/- 0.5 (SEM) and 3.3 +/- 0.5 (SEM) in groups I and II, respectively (p = ns). During follow-up, asympatomatic groin collections were more common in group II (n = 4) than group I (n = 2) (p = ns).

CONCLUSIONS

Compared to local wound infiltration with bupivacaine, the extraperitoneal instillation of bupivacaine did not bestow any additional analgesic benefits. Therefore, the routine infiltration of skin incisions with bupivacaine is recommended after endoscopic extraperitoneal inguinal hernioplasty.

Pharmacotherapies for attention-deficit/hyperactivity disorder: expected-cost analysis

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a common childhood neurobehavioral disorder characterized by inattention, hyperactivity, and impulsivity. Prevalence estimates in elementary school children generally range from 3% to 8%. ADHD is frequently treated with psychostimulant medications, which have been shown to improve both cognitive and behavioral outcomes for most children.

OBJECTIVE

The goal of this study was to estimate the total expected costs for the treatment and management of school-age children with ADHD using 6 commonly prescribed pharmacotherapies: methylphenidate immediate-release/extended-release (MPH IR/ER), methylphenidate immediate-release (MPH IR), Metadate CD (branded MPH IR/ER), Concerta (branded MPH ER), Ritalin (branded MPH IR), and Adderall (a combination of dextroamphetamine and amphetamine salts).

METHODS

A literature review and clinical assessment using a 27-question survey instrument were used to capture information on the clinical characteristics of ADHD, including common treatment regimens, clinical management of patients, pathways of care, and components of care. A meta-analysis provided response rates for 3 commonly used pharmacotherapies: Metadate CD, MPH IR, and Adderall. Information from the clinical assessment and the meta-analysis were used to populate a decision-analytic model to compute total expected cost for each comparator.

RESULTS

The average total annual expected cost per patient was $1,487 for Metadate CD, $1,631 for Concerta. $1,792 for MPH IR/ER, $1,845 for MPH IR, $2,080 for Ritalin, and $2,232 for Adderall.

CONCLUSIONS

Metadate CD had the lowest total expected cost and Adderall had the highest total expected cost among the ADHD pharmacotherapies evaluated. The differences were attributable to differences in drug-acquisition costs and the need for in-school dosing of twice-daily and thrice-daily medications.

Predictive factors for unanticipated admissions after ambulatory laparoscopic cholecystectomy

HYPOTHESIS

Analysis of the causes of unanticipated admission after ambulatory laparoscopic cholecystectomy may permit the identification of predictive clinical factors for postoperative admission.

DESIGN

Univariate and multivariate analyses of clinical variables associated with unplanned admission in a retrospective case-control series of ambulatory laparoscopic cholecystectomies.

SETTING

A major university-affiliated teaching hospital.

PATIENTS

Seven hundred thirty-one consecutive patients who underwent ambulatory laparoscopic cholecystectomies between January 1, 1996, and December 31, 1999.

INTERVENTION

Ambulatory laparoscopic cholecystectomy.

MAIN OUTCOME MEASURES

Unplanned postoperative admissions. Univariate and multivariate analyses of 19 clinicopathologic factors were performed to identify independent predictive factors for these admissions.

RESULTS

Seven hundred six patients were discharged on the day of operation. The remaining 25 required admission because of pain (n = 10), nausea and vomiting (n = 6), retention of urine (n = 5), patient preference (n = 3), and medical observation (n = 1), giving an unanticipated admission rate of 3.4%. Significant factors associated with unplanned admission included operative duration of longer than 60 minutes and thickened gallbladder wall on ultrasonographic and pathological findings. By means of logistic regression, length of operation was the only independent predictive factor. Operative time exceeding 60 minutes incurred a 4-fold increased risk for unanticipated admission.

CONCLUSIONS

Operative duration was the best predictive factor for unplanned admission after ambulatory laparoscopic cholecystectomy. During selection of patients for day surgery, ultrasonographic demonstration of a thickened gallbladder wall should be taken into consideration.

Laparoscopic repair of incisional hernia

A 75-year-old man developed an incisional hernia over the upper abdomen following a wedge resection of a gastric stromal tumour in 1996. This is the first published report of a successful repair of an incisional hernia via a laparoscopic intraperitoneal on-lay technique using GORE-TEX DualMesh material in Hong Kong. Compared with conventional open repair of incisional hernia, long incisions and wound tension are avoided using the laparoscopic approach. This translates into a reduced risk of wound-related complications and facilitates recovery. In selected cases, minimally invasive surgery is a safe technique for the repair of incisional hernias.

Carboplatin and gemcitabine in metastatic transitional cell carcinoma of the urothelium: effective treatment of patients with poor prognostic features

PURPOSE

To evaluate the activity and toxicity of gemcitabine and carboplatin in consecutive patients presenting with locally advanced or metastatic transitional cell carcinoma of the urothelium (TCC).

PATIENTS AND METHODS

Seventeen consecutive patients referred to a single institution with locally advanced or metastatic TCC were treated with carboplatin AUC 5 on day 1 and gemcitabine 1000 mg/m2 on day 1 and 8 of a 21-day cycle. All patients were assessable for response and toxicity. Minimal eligibility criteria were used to minimize patient selection.

RESULTS

Seventeen patients with measurable stage IV TCC of the urothelium were treated. The median age was 69 years (range 54-78), the median creatinine clearance was 56 ml/min (range 34-90) and 30% of patients had an ECOG performance score of two. Nine patients (53%) had visceral metastases and the majority of patients had multiple sites of metastases. There were three complete responses, seven partial responses, for an overall response rate of 58.8%. Responses were seen at all sites including the liver. One patient had a response within a previously irradiated field and three patients with prior chemotherapy had responses. Median overall survival was 10.5 months and median time to progression was 4.6 months. Toxicity was primarily haematologic with six patients having grade 3 neutropenia and six patients with grade 4 neutropenia. There were five cases of grade 3 and three cases of grade 4 thrombocytopenia. There were no episodes of febrile neutropenia and only one patient required admission for management of toxicity. Thirteen patients required dose reduction or delay due to neutropenia or thrombocytopenia. There were no treatment-related deaths.

CONCLUSION

The combination of carboplatin and gemcitabine is active in metastatic transitional cell carcinoma of the urothelium with manageable toxicity in a relatively elderly group of patients with some poor prognostic features.

Carotid artery aneurysm secondary to cystic medial necrosis

Carotid artery aneurysm secondary to cystic medial necrosis is a rare clinical entity. We report a 59-year-old Chinese male patient who presented with a pulsatile right neck swelling for 2 months. Partial resection of the aneurysm with primary anastomosis of the internal carotid artery was performed. Histopathological examination of the aneurysmal wall demonstrated cystic degeneration of the media with accumulation of glycosaminoglycan material, consistent with the features of cystic medial necrosis. The pathogenesis of carotid artery aneurysm secondary to cystic medial necrosis is discussed.

Long-term prognosis of femoropopliteal bypass: an analysis of 349 consecutive revascularizations

BACKGROUND

Femoropopliteal bypass is the commonest procedure for lower limb revascularization. The aim of the present study was to determine the long-term outcomes of femoropopliteal bypass and evaluate the prognostic significance of various clinical factors on the long-term results.

METHODS

From 1976 to 1998, 349 consecutive primary femoropopliteal bypass operations were performed on 314 patients at the University of Hong Kong Medical Centre. Indications for operation included claudication (n = 85) and limb-threatening ischaemia (n = 264). Univariate and multivariate analyses of 14 clinical variables were undertaken to identify significant prognostic factors affecting the graft patency, limb salvage and patient survival rates.

RESULTS

The overall primary patency rates of femoropopliteal bypass were 88%, 79% and 76% at 1, 3 and 5 years, respectively. Type of graft material and age of patient were independent prognostic factors of graft patency. The cumulative limb salvage rates were 90%, 86% and 86% at 1, 3 and 5 years, respectively. No clinical factor was found to be predictive of ultimate limb loss. The overall survival rates were 89%, 85% and 78% at 1, 3 and 5 years, respectively. Coronary artery disease was the main cause of late death. Gender and indication for operation were the significant predictive factors of long-term survival.

CONCLUSIONS

Femoropopliteal bypass using reversed long saphenous vein provided the most durable long-term patency. Autologous saphenous vein should be the choice of vascular conduit if available. Male gender and limb-threatening ischaemia were associated with a poor survival.

Comparison of spiral CT angiography with conventional digital subtraction angiography in the evaluation of renal transplant donors: a pilot study

Conventional digital subtraction renal arteriography (IA-DSA) has been traditionally used as the preoperative imaging modality for assessment of renal vascular anatomy for renal transplant donors. This study evaluates the potential use of spiral CT angiography in replacing IA-DSA in the preoperative assessment of this group of patients. Seven patients underwent both spiral CT angiography and IA-DSA between October 1997 and April 1998. It is concluded that spiral CT angiography can demonstrate the number, length and location of renal arteries and it is suggested that spiral CT angiography can potentially replace IA-DSA in the preoperative assessment of renal donors.

Is the preferential use of ePTFE grafts in femorofemoral bypass justified?

The choice of prosthetic graft material for cross-femoral bypass has been evolving in the past two decades. Expanded polytetrafluoroethylene (ePTFE) has become our preferred graft material since 1995. However, few studies have looked into the optimal graft material in this procedure. Justification for the preferential use of ePTFE graft in lower limb revascularization remains unknown. The aim of the present study was to compare the long-term outcomes of Dacron and ePTFE grafts in femorofemoral bypass. The records of 61 consecutive patients who underwent femorofemoral bypass at the University of Hong Kong Medical Center from 1981 to 1998 were retrospectively reviewed. Dacron grafts were used in 27 patients and 34 patients had ePTFE grafts. The demographic features, patency, and limb salvage rates of the two groups of patients were compared. The 3-year primary patency rates of Dacron and ePTFE grafts were 85% (SE = 9.5%) and 66% (SE = 14.5%), respectively. The difference was not statistically significant. The limb salvage rates of Dacron and ePTFE grafts were 91% and 83% at 3 years, respectively (p = 0.27). The long-term outcomes of Dacron and ePTFE grafts in femorofemoral bypass were equivalent. The preferential use of ePTFE graft in femorofemoral bypass is not evidence based. Selection of an appropriate prosthetic graft for femorofemoral bypass should be based on the cost and its handling characteristics.

A prospective study of early tactile stimulation after digital nerve repair

Forty-nine patients with 65 digital nerve injuries were randomized into two groups after nerve repair. Group 1 received early tactile stimulation and Group 2 was a control group. The patients were assessed prospectively for 6 months for recovery of functional sensibility. Tactile stimulation in Group 1 was provided from 3 weeks after nerve repair with a specially designed rotating tactile stimulator and a pocket tactile stimulator. Constant two-point discrimination, moving two-point discrimination, and cutaneous pressure threshold were measured and sensibility was graded with the Medical Research Council (UK) sensibility grading. At 6 months, 68.8% of patients in Group 1 had a Medical Research Council grading of S3+ or S4 sensibility compared with 36 % in Group 2. With this prospective randomized study, the value of sensory reeducation in improving sensibility after digital nerve injury was confirmed. Starting tactile stimulation from the early postoperative period is recommended; however, use of the rotating tactile stimulator and pocket tactile stimulation need additional study.

Determinant factors of pain after ambulatory inguinal herniorrhaphy: a multi-variate analysis

Pain is common after inguinal herniorrhaphy. The objective of our study was to evaluate the significance of various clinical factors on the level of post-operative pain after ambulatory inguinal herniorrhaphy. Between January, 1996 and December, 1998, 239 ambulatory inguinal hernia repair patients were recruited. Operative techniques included nylon darn (n = 152), modified Bassini repair (n = 56), and prolene mesh hernioplasty (n = 30). Linear analogue pain scores--ranging in value from 0 to 10--were assessed by telephone interviews on the first and third post-operative days. Uni-variate and multi-variate analyses were performed to identify the significant independent determinant factors affecting the severity of post-operative pain. Clinical factors studied were age, sex, operative technique, hernia anatomy and post-operative complication(s). By uni-variate analysis, patients of age < or = 50 years and indirect inguinal hernia were associated with a significantly higher pain score on the first postoperative day 1. On post-operative day 3, patients of age < or = 50 years, with an indirect inguinal hernia and modified Bassini repair reported a significantly higher pain score. Following inguinal herniorrhaphy, multiple regression analysis showed that age was the only independent predictive factor of pain score on post-operative days 1 and 3. In conclusion, post-operative pain was not affected by surgical technique, sex, hernia anatomy and post-operative morbidity. Only age had a significant influence on the post-operative pain score following ambulatory inguinal herniorrhaphy. Therefore, the age of a patient should be taken into consideration when prescribing post-operative analgesics.

Clinical factors influencing return to work after ambulatory inguinal herniorrhaphy in Hong Kong

Ambulatory inguinal hernia repair is the commonest day case general surgery operation. The present study was conducted to evaluate factors influencing the contemporary pattern of convalescence following ambulatory inguinal hernia repair in Hong Kong. A total of 271 consecutive ambulatory inguinal hernia repairs were performed at a day surgery centre from December 1995 to December 1998. The convalescent period prior to resuming work was analysed by multi-variate analysis with respect to significant clinical variables. A sick leave of 3 weeks was adequate for most patients following uncomplicated ambulatory inguinal hernia repairs. Factors associated with early return to work included age </=50 years, indirect inguinal hernia and sedentary occupation. Occupation was the only independent factor affecting the duration of time off work on multi-variate analysis.

Efficacies of lipophilic inhibitors of dihydrofolate reductase against parasitic protozoa

Competitive inhibitors of dihydrofolate reductase (DHFR) are used in chemotherapy or prophylaxis of many microbial pathogens, including the eukaryotic parasites Plasmodium falciparum and Toxoplasma gondii. Unfortunately, point mutations in the DHFR gene can confer resistance to inhibitors specific to these pathogens. We have developed a rapid system for testing inhibitors of DHFRs from a variety of parasites. We replaced the DHFR gene from the budding yeast Saccharomyces cerevisiae with the DHFR-coding region from humans, P. falciparum, T. gondii, Pneumocystis carinii, and bovine or human-derived Cryptosporidium parvum. We studied 84 dicyclic and tricyclic 2,4-diaminopyrimidine derivatives in this heterologous system and identified those most effective against the DHFR enzymes from each of the pathogens. Among these compounds, six tetrahydroquinazolines were effective inhibitors of every strain tested, but they also inhibited the human DHFR and were not selective for the parasites. However, two quinazolines and four tetrahydroquinazolines were both potent and selective inhibitors of the P. falciparum DHFR. These compounds show promise for development as antimalarial drugs.

Duration of effect of botulinum toxin type A in adult patients with cervical dystonia: a retrospective chart review

BACKGROUND

Clinical trials have established the efficacy and safety of botulinum toxin type A (BTX-A) in patients with cervical dystonia. To maintain the clinical benefits of BTX-A, injections need to be repeated whenever patients' symptoms begin to recur.

OBJECTIVE

The purpose of this study was to determine, in clinical practice settings, the mean duration of effect of BTX-A in the treatment of adult patients with cervical dystonia.

METHODS

A retrospective chart review was undertaken at an academic center and a private neurology practice. At each site, > or =50 patients being treated for cervical dystonia were identified and randomized for chart review. Patients had to have received the first assessable injection of BTX-A between January 1, 1998, and March 31, 1998, to coincide with the clinical availability of the most current formulation of the neurotoxin. A chart was eligible for review if the patient was aged > or =18 years, had a documented diagnosis of idiopathic cervical dystonia, was being treated with BTX-A, and had been under the continuous care of investigators from January 1, 1998, to August 31, 1999. Of the 102 patients initially identified, the first 30 from each site who met the study inclusion criteria were assessed for (1) age and sex; (2) severity of dystonia; (3) years of BTX-A use; (4) dates of first, second, third, and fourth BTX-A injections; (5) drug dose; (6) use of electromyography; (7) use of other prescribed therapies; (8) laboratory tests; and (9) adverse events. The mean interval between each visit and mean per-patient duration of effect were calculated and stratified by patient characteristics.

RESULTS

The mean age of the patients was 56.4 years. Two thirds of the patients were women. Forty-one of the 60 patients (68.3%) had either moderate or severe disease, and 48 (80.0%) had experienced cervical dystonia for >5 years. The mean per-patient duration of effect across the 4 visits was 15.5 weeks (range, 12.2-24.3 weeks). The duration of effect did not differ significantly between study sites despite the differences in disease severity, drug dose, and use of adjunctive therapy.

CONCLUSION

BTX-A the controls symptoms of cervical dystonia for 12 to 24 weeks, with a mean duration of effect per patient of 15.5 weeks.

Population PK and PK/PD modelling of microencapsulated octreotide acetate in healthy subjects

AIMS

To develop a population model that can describe the pharmacokinetic profile of microencapsulated octreotide acetate in healthy cholecystectomized subjects. To investigate the correlation between serum IGF-1 and octreotide concentration.

METHODS

A population pharmacokinetic analysis was performed on octreotide data obtained following a single dose of 30 mg microencapsulated octreotide acetate intramuscularly. The relationship between serum IGF-1 concentration and octreotide concentration was effectively described by a population pharmacokinetic/pharmacodynamic model.

RESULTS

The pharmacokinetic profile of octreotide was characterized by an initial peak of octreotide followed by a sustained-release of drug. Plateau concentration were sustained up to day 70, and gradually declined to below the detection limit by day 112. A one-compartment linear model was constructed which consisted of two absorption processes, characterized by KIR and KSR, rate constants for immediate-release and sustained-release, respectively, with first-order elimination (Ke; 1.05 h-1). The surface, unencapsulated drug was immediately absorbed into the central compartment with first-order absorption (KIR; 0.0312 h-1), while the microencapsulated drug was first released in a zero-order fashion into a depot before being absorbed into the central compartment with first-order absorption (KSR; 0.00469 h-1) during a period of tau (1680 h). Body weight and gender were important covariates for the apparent volume of distribution. The type of formulation was an important covariate for KIR but had no effect on KSR. An inhibitory Emax population pharmacokinetic/pharmacodynamic model could adequately describe the relationship between IGF-1 (expressed as percent baseline) and octreotide concentration. Baseline IGF-1 concentration was found to be a significant covariate for the baseline effect (E0). A relationship between GH concentration and octreotide concentration was not established.

CONCLUSIONS

The pharmacokinetic profile of microencapsulated octreotide acetate was effectively described by the derived population model. The relationship between IGF-1 and drug concentration could be used to guide optimization of therapeutic octreotide dosage regimens.

Laparoscopic totally extraperitoneal inguinal hernioplasty: an audit of the early postoperative results of 100 consecutive repairs

INTRODUCTION

With the establishment of a hernia specialist service at our medical centre in 1999, laparoscopic inguinal hernia repair was offered to all patients who presented with inguinal hernias. This is a report of our early experience of 100 consecutive laparoscopic totally extraperitoneal inguinal hernioplasties.

MATERIALS AND METHODS

Between June 1999 and January 2000, a total of 82 patients with 100 inguinal hernias underwent laparoscopic totally extraperitoneal hernioplasties. The mean age of the study population was 64 +/- 16 (SD) years with a male to female ratio of 79:3. A prospective evaluation and analysis of perioperative outcomes were performed.

RESULTS

A total of 97 laparoscopic extraperitoneal inguinal hernioplasties were successfully performed. Three patients required conversion to transabdominal preperitoneal repair because of adhesion (n = 1), large peritoneal defect (n = 1) and the presence of bowel within hernial sac (n = 1). There were no other intraoperative complications. Postoperative morbidity included retention of urine (n = 4), asymptomatic groin collection (n = 4) and wound bruising (n = 2). All complications resolved uneventfully. The visual analogue pain score at rest was 2, 1 and 1 on postoperative days 0, 1 and 2, respectively. The mean length of hospital stay was 2 +/- 1 (SD) days. Forty-seven patients (57%) returned to normal activities within one week.

CONCLUSIONS

The early outcomes of laparoscopic extraperitoneal inguinal hernioplasties were encouraging. It confirmed the early success of laparoscopic repairs of inguinal hernias at our centre. Laparoscopic approach is a safe technique for repair of inguinal hernia in specialised centres.

Long-term outcome of aortofemoral bypass for aortoiliac occlusive disease

INTRODUCTION

Revascularisation of aortoiliac occlusive disease has been evolving in the past 2 decades. The present study was undertaken to evaluate the long-term outcomes of aortofemoral bypass for aortoiliac occlusive disease at a tertiary vascular disease centre in Hong Kong.

MATERIALS AND METHODS

A retrospective analysis of 94 patients (176 limbs) who survived aortofemoral bypass was performed to evaluate the graft patency, long-term complications, limb loss and patient survival rates. Thirty-six patients were operated for incapacitating claudication (Group I) and 58 for limb salvage (Group II).

RESULTS

The overall primary patency rates of aortofemoral bypass were 97%, 90%, 89% and 84% at 1, 3, 5 and 10 years, respectively. Poor distal run-off and neointimal hyperplasia were the leading causes of late graft failure. Other late complications included femoral pseudoaneurysm (n = 1), infection (n = 1) and femoral graft aneurysms (n = 2). The limb loss rate was 5.1% at 4 years. The overall survival rates were 95%, 86%, 81% and 75% at 1, 3, 5 and 10 years, respectively. Ischaemic heart disease and malignancy were the 2 major causes of late death. The 5-year survival rate of group I patients (96%) was significantly superior to that of group II patients (70%).

CONCLUSIONS

Aortofemoral bypass achieved a primary patency rate of 89% at 5 years and a satisfactory limb salvage rate. It remains the preferred treatment option for good risk patients with complete occlusion or extensive stenosis of the aortoiliac arteries.