Tibial vessel injuries (3) - Repair of the posterior tibial artery!

Fig: Spiral CT and Intra -Operative photo

 

Tibial vessel injuries are generally managed conservatively as one of the three is usually is patent and supplies adequate blood to the distal leg and foot. Rarely we see all the three vessels are injured and distal foot is ischemic. In such situations we do consider repair of one of the tibial vessels to save the ischemic foot. In this case ( fig) posterior tibial artery was repaired ( resection and anastomosis) and the other occluded vessels are not repaired. Nerve injury is left for the secondary repair. At the end of the procedure the repaired posterior tibial artery is pulsting well beyond the anastomosis. 

 

 

Cattle as MRSA reservoir? Can MRSA get transmitted in Milk?

Penicillin binding protein 2a is encoded by the gene mecA. It imparts the resistance to the bacteria against antibiotics. The resistance of the staphylococci is due to the acquisition of one of the several SCCmec elements carrying the gene mecA. PCR test can detect the mecA gene. PBP2a is detected by the agglutination assay.

A novel mecA homologue, mecALGA251, associated with resistance to β-lactam antibiotics was present in clinical MRSA isolates from the UK and Denmark, and bovine milk samples from the UK. This is giving raise to an alarm that the cattle can be a reservoir for the MRSA which can get transferred to the humans. In the recent past there was lot discussion about the NDM1 betalactamase producing MRSA infections and their spread across the continents. Now we are hearing that the milk and probably milk products also associated with risk of carrying the MRSA infections. It is alarming to note the ability of staphylococcus to spread with the capabilities of antibiotic resistance across the continents and species too.

Ref: The Lancet Infectious Diseases, Early Online Publication, 3 June 2011

Biomechanical properties of AAA – what does it mean to clinicians who are faced with dilemma  - To do or not to do an intervention based on the size of the AAA?

 

Abdominal aortic aneurysms are feared in the clinical practice as they are known to rupture without a prior notice and result in death. This clinical fear of rupture supports the treatment of the large aneurysms even though they are asymptomatic. But, open operative repair of the small AAA is associated with significant risks which are more in units which are not considered large volume centers. That means we have to be more selective in identifying the AAAs which are likely to rupture based on their wall ability to withstand the stress and strain.  The bio mechanical properties of the normal aortic wall and aneurysm wall are definitely going to help us in selecting the patients for early repair in addition to the diameter.

In the year 1966 Szilagyi et al observed that the aneurysms larger than 6 cm are at increased risk of rupture.  Later Foster and colleagues noted similar observations (< 6cm – 16% .,  >6cm 51%  rupture). For the next 4 decades the diameter of the aneurysm dictated the decision to operate. Now we are looking at the other parameters such as “wall stress”. 

Finite Element analysis (2002) was introduced by Fillinger colleagues was used to assess the wall stress in the aortic aneurysms (see fig). The figure shows stress as Newtons/ cm². The point of maximum stress need not be over the maximum diameter point. There are many factors in wall structure which could be deciding the strength of the wall to resist the breakdown. Finite element analysis method was used by engineers to study the elastic properties and strength the materials. The same is applied to the biological materials where the shapes are variable such as the aortic dilatation.  In women the aneuryms with small diameters are also risk of rupture (5cm). The measurement of wall stress with finite element analysis is not universally accepted and validated as a method for assessing risk of rupture. But in the coming years it may be available in our neighborhood and we may assess the aneurysms with this method to predict rupture. This is comparable to the foot pressures (pedobarograph) to assess the development of plantar foot ulcers. Probably we will be able to get this information along with CT scan report and imagine the ease with which the surgeon can tell his patients about the need for interventions.

 

HbA1c: an old friend in new clothes

Equivalent DCCT-aligned and IFCC-standardised values

DCCT=Diabetes Control and Complications Trial. 

IFCC=International Federation of Clinical Chemistry.

 

In the recent past the importance of measuring HBA1c is recognized at various levels in the management of diabetic people. But there is concern about the reliability of the HBA1c done from different laboratories which is variable between 3% to 14%. IFCC standardized the value as mmol/mol and said that it should be less than 48 mmol/mol to say some is non diabetic that is equal to <6.5gm%. It is said that in future we will be using this measure in all the studies and clinical practice to avoid the variations in the older measurement of HBA1c. We need to wait and see in India for this change. This paper is presented in the Lancet 30 April 2011

Vascular malformation in the left Supra Clavicular region

Tuberculosis in Vascular surgical patients: 

Peripheral Vascular disease patients are usually smokers and there is a good possibility that they had tuberculosis at some point of time in their life.  Recently a 50 year old smoker was referred to our clinic (emaciated  and BMI less than 18) with left upper limb ischemia.Clinically he looks like a patient of tuberculosis. X-ray showed changes of chronic both lung disease and fibrosis. The physicians are hesitating to admit the patients after Brachial artery thrombectomy in the TB hospital as they are not convinced of the active nature of the tuberculosis. Surgeons are hesitant to admit such a patient in the surgical ward where more than 15 Post operative patients are lodged with common toilet facilities.We can do the thrombectomy under local anesthesia in 15-20 minutes safely. After that it is advisable to treat such patients in outpatient departments safely. It took more than 1 hour to convince the patient and his relatives to accept and wear a face mask to prevent the spread of potential tuberculosis or other diseases to the neighbors. In a recent Lancet report it was mentioned that although tuberculosis prevails in mainly high-burden developing countries, cases in immigrants in many low-incidence countries are increasing substantially. This changing pattern of disease is clear in the UK where, between 1998 and 2009, tuberculosis notifications have risen by 46%, from 6167 cases to 9040, with much of this rise fueled by the 98% increase in cases from overseas.These individuals account for nearly three-quarters of all tuberculosis notifications in the UK with an incidence that is 20 times higher than in UK-born individuals (89 cases per 100 000 people per year vs 4 per 100 000). We have to note importance of these reports more seriously and provide or display information about tuberculosis to the patients in the high turnover hospitals (in notice boards or as wall posters) at regular intervals to sensitize the patients about the possibility of easy spread of Tuberculosis bacilli which are getting resistance to the currently available drugs. 

Medical Errors!

There is concern about the medical errors in the hospitals in developing countries and developed countries. India is going to increase the number of hospital beds. The number of hospital admissions will increase in the coming years and so are the medical errors. The US Institute of Medicine's landmark 1999 report, To Err is Human: Building a Safer Health System, estimated that avoidable medical errors contributed annually to 44 000—98 000 deaths in US hospitals. Hospital-based errors were reported as the eighth leading cause of death nationwide, ahead of breast cancer, AIDS, and motor-vehicle accidents. The report put medical errors under the national spotlight.
Who or what is to blame for medical errors and their consequences? Overworked providers, an unnecessarily complex medical system, or uninformed patients? Patients are often handed from one doctor to another and, in the process, communication between providers can break down. Time spent filling out paperwork is time not spent with patients improving the quality of their care. Decision making often does not involve informing a patient about the balance between benefits and harms of individual treatments, or incorporating patients' goals into planned treatment. And it does not help that existing guidelines allow medical residents in the USA to work on average 28 h more per week than junior doctors in countries of the European Union. In  India we need to follow the guidelines more strictly and teams should adhere to the standard protocols to reduce the medical errors.
The medical errors can turn out to be very expensive to the society and hospitals. Hospitals must develop protocols and check lists to prevent the medical errors. 

Transdermal cutaneous Oxygen therapy ( EPIFLO)

We are looking for the newer and simpler therapies for treating the chronic non healing ulcers. In the recent past negative pressure wound therapy (NPWT) has been made available in Indian hospitals. Hyperbaric oxygen therapy is used in very few centers in India for treating the non healing ulcers. But the new concept of delivering the oxygen (3 ml/hour) directly in to the wound through a small device which concentrates the oxygen from the atmosphere seems to have advantages over the other methods available to us.  This device ( Fig) is small and can be tied to the extremity very easily and patient can be mobile and expect good healing of wound within 15 to 30 days. There seems to be a definite place for this device in the vascular surgeon's clinical practice. 

World Malaria Day -25th April

According to World Health Organisation statistics, Malarial parasite infected around 225 million and killed nearly 800,000 people worldwide in 2009. They seem to be developing resistance to the available drugs. In the recent studies it was found that the parasite is dependent on the kinases in the cells ( liver, RBCs) for their survival and multiplication. If these kinases are inhibited then it becomes a halt for parasite. Now there is a new hope that the newer Cancer drugs can kill malaria parasite Plasmodium, which is transmitted via the bites of infected mosquitoes. In the human body, the parasites reproduce in the liver, and then infect and multiply in red blood cells. Joint research by few organizations showed that, in order to proliferate, the malaria parasite depends upon a signalling pathway present in the host's liver cells and in red blood cells. They demonstrated that the parasite hijacks the kinases (enzymes) that are active in human cells, to serve its own purposes. When the research team used cancer chemotherapy drugs called kinase inhibitors to treat red blood cells infected with malaria , the parasite was stopped in its tracks.

Endovascular repair of the aneurysms of descending thoracic aorta and abdominal aorta in the same sitting

We are concerned about many issues if there is a patient with Thoracic and abdominal aorta aneurysm asking for the Endo vascular repair of the aneurysms aneurysm in the same sitting. Paraplegia is always a concern when a large extent aorta is covered by the endograft. Recently I, myself along with a cardiologist repaired both the aneurysms in the same sitting but we preserved the left subclavian artery (Chimney) and left internal iliac artery with a hope to avoid the paraplegia. We noted that it was also done in  other centers, with minimal morbidity ( see the reference below). There is also concern about the amount of contrast injection and overload. But for the patient it may be convenient to get the both repaired in one sitting. Similarly groin exploration by the vascular surgeon may be difficult and time consuming during the second time.  One has to certainly weigh the benefits and risks of repairing the both aneurysms in one sitting.

Reference:

Interact Cardiovasc Thorac Surg. 2011 Feb 5. 

Stenting of the descending thoracic aorta: a 6-year single-center experience.Matsagkas MI, Kirou IE, Kouvelos G, Arnaoutoglou EM, Papakostas JC, Katsouras C, Papadopoulos G, Michalis LK. Department of Vascular Surgery Unit, School of Medicine, University of Ioannina, Ioannina, Greece. Objectives: The aim of this study was to review the six-year results of the endovascular repair of descending thoracic aortic pathologies, reporting the early perioperative outcomes as well as the mid-term follow-up of the treated patients. Methods: Fifty-five consecutive patients who underwent endovascular repair for thoracic aortic pathology (29 aneurysms, 17 acute thoracic aortic syndromes, and six traumatic aortic ruptures) during a six-year period were retrospectively reviewed. From these patients, 30 (54.5%) were treated electively and 25 (45.5%) on an emergency basis. In eight cases (14.5%) there was a need for left subclavian artery orifice overstenting. In seven patients (12.7%) an abdominal aortic lesion was simultaneously treated, while three more patients (5.5%) had previously had their abdominal aortic aneurysm repaired. Results: The primary technical success was 92.7%. Seven patients (12.7%) underwent some operation related complication, while postoperative complications occurred in five patients (9.1%), namely four myocardial infarctions, one acute respiratory distress syndrome and two delayed parapareses resulting in an overall incidence of neurological complications of 3.6%. The combined 30-day and in-hospital mortality was 9.1%, exclusively related to patients treated emergently (P=0.01). In a mean follow-up period of 34 months there were six deaths, and the overall cumulative survival at four years was estimated at 72.6%. Only one type II endoleak was observed one month after the procedure and it spontaneously disappeared 18 months later. Conclusions: The endovascular repair of descending thoracic aortic pathologies seems to be a well-established method, with favorable morbidity and mortality rates, at least for 30 days and in the mid-term. Taking into account the potential of a wide application of the endovascular technique in many vascular centers, stenting of the thoracic aorta might offer an overall better solution for patients suffering from these devastating pathologies. Keywords: Endovascular repair; Descending thoracic aortic pathology; Stent-graft.

Anticoagulant Options — Why the FDA Approved a Higher but Not a Lower Dose of Dabigatran for non valvular atrial fibrillation

NEJM | April 13, 2011 | Topics: Drugs, Devices, and the FDA

On October 19, 2010, the Food and Drug Administration (FDA) approved dabigatran for the reduction of the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation. Approval was based on a multicenter, active-control trial, the Randomized Evaluation of Long-Term Anticoagulation Therapy (RE-LY), in which patients were randomly assigned to receive 150 mg of dabigatran, 110 mg of dabigatran, or warfarin. Dabigatran was given twice daily; warfarin was titrated to achieve an international normalized ratio (INR) of 2.0 to 3.0. Assignment to warfarin or dabigatran treatment was unblinded; assignment to a specific dabigatran dose was double-blind. RE-LY was a noninferiority study, attempting to rule out a hazard ratio of more than 1.38 for the primary end point, stroke or systemic embolism.

vascular ( blood vessels)

http://www.sciencedaily.com/

Increase in Deaths in Men With Type 2 Diabetes and Testosterone Deficiency May Be Prevented by Testosterone Replacement?

Professor Jones' team conducted a six year study of 587 men with type 2 diabetes, splitting them into three groups: those with normal total testosterone levels (above 10.4nmol/L, n=338), those with low testosterone levels (below 10.4nmol/L) that weren't treated with testosterone replacement therapy (n=182), and those with low testosterone levels treated with testosterone replacement therapy for two years or more during the follow up period (n=58).

The findings show for the first time that low testosterone puts diabetic men at a significantly increased risk of death (p=0.001 log rank): 36 of the 182 diabetic men with untreated low testosterone died during the six year study, compared to 31 of the 338 men with normal testosterone levels (20% vs 9%). Furthermore, only 5 of the 58 diabetic men that were given testosterone replacement therapy died during the study (8.6%), meaning they showed significantly better survival compared to the non-treated group (p=0.049 log rank).
This is the first study to show testosterone treatment can improve survival in men with type 2 diabetes and testosterone deficiency. Further studies now need to be carried out to fully investigate the potential therapeutic benefit of testosterone replacement in diabetic men with low testosterone.
Professor Hugh Jones, Consultant Endocrinologist and Hon. Professor of Andrology, Barnsley Hospital NHS Foundation Trust and the University of Sheffield, said: "This is potentially a very exciting finding. Whilst we have shown that low testosterone levels can put diabetic men at greater risk of dying, we have also demonstrated for the first time the potential benefit that testosterone replacement therapy holds for this group of patients.
"It is well known that men with type 2 diabetes often have low testosterone levels, so it is important that we investigate the health implications of this. We now need to carry out a larger clinical trial to confirm these preliminary findings. If confirmed, then many deaths could be prevented every year."
In another study, also presented at this year's Society for Endocrinology meeting, Professor Jones' group found for the first time that low testosterone and severity of erectile dysfunction are independently associated with a reduced health-related quality of life in men with type 2 diabetes. Health-related quality of life questionnaires, such as the one used in this study, measure how a person perceives their own general health in areas such as physical and social functioning, vitality and pain. The questionnaire does not measure how good a person's health actually is; it measures how good a person thinks their health is in daily life.
In the 356 men with type 2 diabetes tested, health related quality of life decreased as testosterone levels decreased (r=0.353 p=0.044). In the 126 patients who were also assessed for erectile dysfunction, health-related quality of life decreased in the areas including physical functioning (r=0.5, p=0.003), social functioning (r=0.445, p=0.022) vitality (r=0.383, p=0.025) and pain (r=0.428, p=0.012) as the severity of erectile dysfunction increased. Although severity of erectile dysfunction has been shown to be associated with lower testosterone levels, statistical analysis shows for the first time that these are both independently associated with a reduced health-related quality of life in these men.Lead researcher Prof Hugh Jones said: "Our research shows that low testosterone impacts on health-related quality of life in men with type 2 diabetes. This finding supports previous evidence suggesting that erectile dysfunction is a marker of ill health.
"Our next step is to assess whether offering testosterone replacement therapy to diabetic men with testosterone deficiency and erectile dysfunction may help to improve their health related quality of life."

Niacin and mixed dyslipidemia

Niacin (nicotinic acid) lowers lipids by inhibiting very-low-density lipoprotein (VLDL) production in the liver and reducing the level of VLDL that can be converted into low-density lipoprotein (LDL). Niacin can lower LDL cholesterol by 10 to 25 percent and triglyceride levels by 20 to 50 percent, and can raise levels of high density lipoprotein (HDL) cholesterol by 15 to 35 percent. These effects may be even greater in patients with a predominance of small, dense LDL, which has been associated with greater coronary heart disease risk. For these reasons, niacin is considered a useful treatment in patients with mixed dyslipidemia. The adverse effects of immediate-acting niacin preparations, including flushing, itching, gastrointestinal upset and hepatotoxicity, have limited its use. An extended-release form of niacin has to be taken nightly to minimize liver toxicity and other side effects. The daily niacin dosage can be started at 375 mg taken nightly and slowly increased, to a maximum of 3,000 mg per day, at four-week intervals for a total of 25 weeks. Patients can take 325 mg of aspirin before Niacin to prevent flushing.In peripheral vascular surgery patients HDL levels are usually low in Inida. We need to increase the HDL levels in these patients and Niacin is a good  medication for these patients if the side effects such as flushing and other side effects are removed.