Medicine and Health Sciences Commons^™

Analysis Of Indentation Loading Of Cortical Bone Using Acoustic Emission Techniques, Ashkan Safari, Ger Reilly, Brendan Mccormack

Conference Papers

In this study, we recorded the number of Acoustic emission (AE) hits and related AE energy during indentation fracture of cortical bone using a PAC PCI-2 card and pico sensor. A threshold value of 43dB was used to filter premature trigger due to background noise. Registered AE hits had more than one count (threshold crossing). Amplifier gain was set at 40dB with a (0.1-1) MHz band pass filter. 8mm cubes of cortical bones were indented in the longitudinal direction at constant crosshead speed of 1 mm min-1 using a large 2D, 50˚ wedge indenter. We hypothesised that signals occurring as …

Comparison Of Two Surveys Of Head Injured Patients Presenting During A Calendar Year To An Urban Medical Centre 32 Years Apart, Rashid Jooma, Shahid Ahmed, Abdul Malik Zarden

Section of Neurosurgery

Objective: To study the patients presenting with head injuries to a tertiary hospital in Karachi during the year 2003.
Methods: During the calendar year 2003, a cross-sectional study was conducted of all patients presenting to the casualty department of Jinnah Postgraduate Medical Centre (JPMC) with head injury. Personal information was collected from the patient's attendants at presentation or later if the patient had been brought in by the emergency services as an unknown person. The circumstances of the injury were similarly established and the clinical features documented.
Results: During the year 2003, a total of 3008 patients reported to the …

Speech Results With Tracheoesophageal Voice Prosthesis After Total Laryngectomy, Mohammad Sohail Awan, Imtinan Ahmed, Yassar Iftikhar Ahmad, Daniyal Ahmad

Section of Otolaryngology, Head & Neck Surgery

Objective: To assess the success rate of tracheoesophageal voice prosthesis as the primary mode of voice rehabilitation in patients after total laryngectomy.Methods: Medical record files of 35 patients subjected to total laryngectomy were reviewed for determining success or failure of the voice prosthesis. The indicators used were quality of speech and utility of the device. Subsequent complications that developed were also assessed. In addition other factors taken into consideration were pharyngeal myotomy, use of radiation, and timing of replacement. All thirty five patients (n=35) had prosthesis placed at the time of laryngectomy.Results: The success rate at one month and four …

A Case Of Transient Diabetes Insipidus Following Cardiopulmonary Bypass, Omer Ashraf, Hasanat Sharif, Mansoor Shah

Section of Cardiothoracic Surgery

Cardiopulmonary bypass surgery has been linked with a number of postoperative complications. One of the frequently reported physiological alterations is the relative diuresis seen in the immediate post-op period. Rarely reported though is the development of full-blown diabetes insipidus in such patients. The etiology is unknown and has only been hypothesized in the past. We present the clinical course of a 54 year old male who developed transient diabetes insipidus post bypass surgery with subsequent recovery following exogenous vasopressin administration. The physiological alteration leading to the development of diabetes insipidus in a small fraction of bypass patients remains unknown. We …

Dural Metastases Presenting As An Extradural Hematoma: A Rare Presentation, Muhammad Shahzad Shamim, Muhammad Ehsan Bari, S. Ather Enam

Department of Surgery

Abstract

We report a case of an elderly man who presented with hemiparesis and plain CT scan findings highly suggestive of an extradural hematoma as the underlying cause. This patient was later found to have dural metastases secondary to bronchogenic carcinoma. Dural metastases are rare, usually presenting as dural mass, but may also present as chronic subdural or extradural hematoma on non contrast CT scan, leading to an erroneous diagnosis in the unsuspecting.

Metanephric Adenoma: A Rare Benign Renal Tumour, Nausheen Yaqoob, Jai Pal Paryani, Naila Kayani, Mohammad Zafar Rafique, Raziuddin Biyabani

Department of Pathology and Laboratory Medicine

Metanephric adenoma is a rare benign renal tumour. We are reporting one histologically proven such case in a 23 year old male from Afghanistan. He presented with severe right flank pain since 3 weeks. Nephrectomy was done and histopathology was consistent with the diagnosis of metanephric adenoma. This novel renal mass has been reported to have benign clinical course despite its symptomatic presentation and large tumour size. There is no distinguishing radiological feature with can differentiate it from malignant tumours. So far, a uniformly benign clinical course has been associated with Metanephric adenoma, but given its relatively recent identification and …

Detection Of Microcracks During Bone Cutting Using Acoustic Emission Techniques, Ashkan Safari, Ger Reilly, Brendan Mccormack

Conference Papers

Surgeons may use a number of cutting instruments such as osteotomes and chisels to cut bone during operative procedures. The initial loading of cortical bone during the cutting process results in the formation of microcracks in the vicinity of the cutting zone with main crack propagation to failure occurring with continued loading; microcracking acts as a stimulus for main crack formation and has also been shown to occur during the propagation of the main crack. It has also been reported that Acoustic Emission (AE) is generated due to microcrack formation and crack growth, prior to, and during final fracture in …

An Experimental Technique For Measurement Of Heat Generated During Bone Sawing, Hamid Khalili Parsa, Ger Reilly, Brendan Mccormack

Conference Papers

Orthopaedic bone cutting processes such as osteotomy and hip arthroplasty involve the cutting of one with the aid of various manual and powered cutting instruments including manual and powered bone saws. The extent of surgically induced bone necrosis at the point of the cutting tool and the bone is mainly due to the frictional heat generated by bone cutting. Bone necrosis has an impact on bone regeneration, and the rate of healing of the bone post operation. The threshold temperature for impaired regeneration of bone is in the range of 44°C to 47°C. Overheating also affects the sharpness life of …

Clinical Kidney Transplantation: A 50th Anniversary Review Of The First Reported Series, Vivian Charles Mcalister

Surgery Publications

BACKGROUND: Histories of kidney transplantation rarely mention a series reported by Gordon Murray of Toronto and published by the American Journal of Surgery 50 years ago.

METHODS: The papers and biographies of Gordon Murray were reviewed in the context of knowledge at that time about renal failure management to determine their contribution to transplantation research and to current practice.

RESULTS: Murray proceeded from a unique leadership position in vascular surgery, anticoagulation therapy, and dialysis to undertake a rational series of animal experiments and human trials of kidney transplantation that led him to the practices of graft irrigation, cold storage, pelvic …

Sequential Labelling And Acoustic Emission Analysis Of Damage Occurring In Cortical Bone During Indentation Cutting, Ger Reilly, Ashkan Safari, David Taylor, Brendan Mccormack

Conference Papers

When a surgeon uses a wedge shaped blade or an osteotome to cut cortical bone during an operative procedure the bone will fail by a process of microcracking and primary crack propagation. It has previously been observed that crack propagation is dependent on the direction of cutting relative to the main axis of the bone. It has also been observed that microcracks occurring during fracture release acoustic signals that facilitate real-time monitoring of a cutting process. In these novel studies, we labelled damage accumulation during cutting of cortical bone using sequential chelating dyes and we correlated recorded AE signals during …

Leiomyosarcoma Of Thelarynx: A Case Report, Akbar Abbas, Mubasher Ikram, Nausheen Yaqoob

Section of Otolaryngology, Head & Neck Surgery

Leiomyosarcoma of the larynx is an extremely rare neoplasm; only about 50 cases have been reported in the English-language literature. We report a new case of laryngeal leiomyosarcoma in a 65-year-old man. The metastatic work-up was negative, and the patient underwent total laryngectomy. He remained disease-free 12 months postoperatively.

Pulmonary Embolism In Pemphigus Vulgaris, The Need For Judicious Immunotherapy, Omer Ashraf, Hasanat Sharif

Section of Cardiothoracic Surgery

Pemphigus vulgaris is a serious chronic mucocutaneous ailment. In recent decades advances in diagnostic and therapeutic measures have led to a significant decline in morbidity and mortality. However, with the advent of active and prolonged immunotherapy involving corticosteroids, there has been a rise in steroid-associated complications. This has led to significant concern globally over the sensible use of treatment regimen in pemphigus patients. We present a patient who underwent a massive pulmonary embolism following over usage of corticosteroid therapy for pemphigus vulgaris. Whilst the patient survived owing to timely assessment and aggressive surgical intervention, the need for cautious and judicious …

Recollections Of My Research In Developing The Heart-Lung Machine At Jefferson Medical College, Bernard J. Miller

Jefferson Biographies

A personal memoir written by Dr. Bernard J. Miller about his introduction to and interest in medical research as well as his experiences working on the heart-lung machine. He focuses specifically on his working relationship with John H. Gibbon, Jr., the development of a viable oxygenator and ventilator, and early testing of the machine on animals

Prevalence And Predictors Of Smoking In Pakistan: Results Of The National Health Survey Of Pakistan, Khabir Ahmed, Fahim Jafary, Imtiaz Jehan, Juanita Hatcher, Abdul Qayum Khand , Khan, Nish Chaturvedi, Tazeen Jafar

Department of Surgery

No abstract provided.

Sacred Disease Of Our Times: Failure Of The Infectious Disease Model Of Spongiform Encephalopathy, Vivian Mcalister

Vivian C. McAlister

BACKGROUND: Public health and agricultural policy attempts to keep bovine spongiform encephalopathy out of North America using infectious disease containment policies. Inconsistencies of the infectious disease model as it applies to the spongiform encephalopathies may result in failure of these policies.

METHODS: Review of historical, political and scientific literature to determine the appropriate disease model of spongiform encephalopathy.

PRINCIPAL FINDINGS: Spongiform encephalopathy has always occurred sporadically in man and other animals. Hippocrates may have described it in goats and cattle. Transmission of spongiform encephalopathy between individuals is too uncommon for it to be usefully considered an infection. Spongiform encephalopathy is …

Self-Rated Health In Pakistan: Results Of A National Health Survey, Khabir Ahmed, Tazeen Jafar, Nish Chaturvedi

Department of Surgery

Abstract Background: Self-rated health (SRH) is a robust predictor of mortality. In UK, migrants of South Asian descent, compared to native Caucasian populations, have substantially poorer SRH. Despite its validation among migrant South Asian populations and its popularity in developed countries as a useful public health tool, the SRH scale has not been used at a population level in countries in South Asia. We determined the prevalence of and risk factors for poor/fair SRH among individuals aged ≥15 years in Pakistan (n = 9442). Methods: The National Health Survey of Pakistan was a cross-sectional population-based survey, conducted between 1990 and …

Variability In Lipid Profile Before And After Coronary Artery Bypass Grafting (Cabg), M Perwaiz Iqbal, Hasanat Mohammad Sharif, Naseema Mehboobali

Department of Biological & Biomedical Sciences

Objective: To investigate changes in total cholesterol, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, and triglycerides in serum of Pakistani patients before, immediately after and 5 days post CABG.
Method: Serum samples from 31 consecutive Pakistani angina patients undergoing CABG at the Aga Khan University Hospital were analyzed for total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides using kit methods.
Results: Immediately after CABG, there is a significant decline in the mean levels of serum cholesterol, LDL cholesterol, HDL cholesterol and triglycerides. However, 5 days post CABG, there is a significant increase in the concentrations of total …

Gas-Producing Brain Abscess, Arshad A. Siddiqui, Khalid N. Chishti

Section of Neurosurgery

A case of a known psychiatric patient who presented with rapid neurological deterioration is reported. Neuroimaging revealed a gas-producing brain abscess in left parietal lobe with a contiguous focus of infection in the adjacent bone and scalp initiated by obsessive scalp scratching. On complete surgical excision of abscess, followed by culture-based antibiotic therapy, a good neurological recovery was achieved with minimal residual deficits at follow-up.

Olfactory Neuroblastoma: A Case Report And Review Of The Literature, Shehzad Ghaffar, Iftikhar Salahuddin

Section of Otolaryngology, Head & Neck Surgery

Malignant tumors of the nasal cavity are rare. We report the case of an elderly woman who consulted us with a 4-year history of progressive nasal obstruction, occasional epistaxis, facial pain, and watering of the eyes. A diagnosis of olfactory neuroblastoma was established by histopathology and confirmed by immunohistochemistry. On staging, the mass was classified as a Kadish stage B tumor. The mass was excised via a lateral rhinotomy approach, and the tumor was peeled away completely from the cribriform plate with endoscopes. The patient underwent postoperative radiation, and she was free of recurrence at follow-up 15 months later.

Demarcated Truncal Jaundice: A Sign Of Retroperitoneal Bile Leakage, Vivian C. Mcalister, Alp Sener

Vivian C. McAlister

The characteristic feature of the clinical sign described here is the demarcation between jaundiced and unaffected areas of the body. The flanks and the genitalia are stained more than would be expected by examination of the sclera or estimation of bilirubin level. Superiorly, a horizontal line about 3 cm below the clavicles, corresponding to the insertion of the fascia of Scarpa into the clavipectoral fascia, allows an easy comparison between the jaundiced trunk and unaffected adjacent areas, such as the neck, shoulder, and arm. Similarly, a line 3 cm below the groin skin crease corresponds to the insertion of the …

Surgical Images: Soft Tissue. Incarcerated Gallbladder In A Parastomal Hernia., Shawn D. St Peter, Jacques Heppell

Manuscripts, Articles, Book Chapters and Other Papers

No abstract provided.

An Investigation Of The Heat Affected Zone In Cortical Bone Sawing, Hamid Khalili Parsa, Ger Reilly, Brendan Mccormack, Andrew Macey

Conference Papers

Surgical procedures such as osteotomy and hip replacement involve the cutting of bone with the aid of various manual and powered cutting instruments including manual and powered bone saws. Frictional rubbing between the blade of the saw and the bone results in the generation of localised heating of the cut bone and increased cutting forces (Ark et al, 1997). Overheating in localised areas can cause bone necrosis and have an impact on the rate of healing of the bone post operation and overheating also affects the sharpness life of the blade. A review of the literature indicates that work has …

Robot Assisted Ultrasound Imaged Guided Interstitial Lung Brachytherapy In A Porcine Model, Richard A. Malthaner, Edward Yu, Jerry J. Battista, Chris Blake, Donal Downey, Aaron Fenster

Oncology Presentations

We set out to see if permanent interstitial brachytherapy seeds could be safely and reproducibly inserted thoracoscopicaly with the ZEUS Robotic system and intraoperative ultrasound into in-vivo porcine lungs.

Extended Vs. Small Field Irradiation In High Risk Post Esophagectomy Patients Receiving Combined Chemoradiation Therapy: A Decade Experience In Treatment Of Esophageal Cancer, Edward Yu, Patricia Tai, George Rodrigues, Robert Ash, Larry Stitt, Rashid A. Dar, Pauline Truong, Gregory M. Videtic, Richard Malthaner, Richard Inculet, Anna Tomiak, Jawaid Younus, Brian Dingle, Walter Kocha, Mark Vincent

Oncology Presentations

OBJECTIVE: To assess the impact of extended field irradiation with anastomotic coverage on local recurrence in high risk resected esophageal cancerpatients.

METHODS: From 1989-1999, high risk resected esophageal cancer cases receiving post-resection chemoradiation were reviewed. Adjuvant chemotherapy consisted of four cycles of fluorouracil-based regimens. Loco-regional irradiation with or without coverage of anastomotic site had radiation a dose range from 45-60 Gyat 1.8-2.0 Gy/fraction given with initial anterior-posterior/posterior-anterior arrangement with either extended (with anastomotic coverage), or small (without anastomotic coverage) field followed by oblique fields for boost.

RESULTS: One hundred eighty-eight charts were reviewed. Seventy-two patients were eligible for post-resection chemoradiation. …

Bacillus Calmette-Guerin (Bcg) Lymphadenitis: Changing Trends And Management, Zafar Nazir, Saqib Hamid Qazi

Section of Paediatric Surgery

Background: Bacillus Calmette-Guérin (BCG) vaccination is performed as a part of expanded Programme of Immunization (EPI). Suppurative lymphadenitis is the common complication of BCG vaccination. The optimum treatment for this complication is debated.
Methods: All cases of BCG lymphadenitis presenting to pediatric surgical service over a 17-year study period were reviewed to determine the optimum treatment for this problem.
Results: Sixty children were referred for the management of BCG lymphadenitis during the study period. Most patients (n=43) presented during 1988 and 1990. Children were healthy and received BCG (Pasteur strain) vaccination at EPI during first 2 months of life. Initially …

Delayed Supramalleolar Flap: An Innovative Technique For Enhanced Viability, Syed Kamran Ahmed, Pervaiz Mehmood Hashmi

Section of Orthopaedic Surgery

Background: Delaying flap rotation for 48 to 72 hours leads to opening of choke anastomotic vessels linking adjacent vascular territories. This mechanism enhances flap circulation. Lateral supramalleolar flap with larger dimensions or vascular variations can potentially have survival problems. The purpose of this study is to assess the outcome of delayed lateral supramalleolar flap.
Methods: This descriptive case series was conducted at Aga Khan University Hospital, Karachi from May 1999 to December 2004. Eight cases of delayed lateral supramalleolar flap were identified through medical records maintained through Health Information Management Systems (HIMS). A detailed questionnaire was developed addressing variables of …

Non-Traumatic Aortic Emergencies - Experience From A Tertiary Care Centre In, Nadeem Khan Ullah Khan, Junaid A. Razzak, Hasanat Sharif, Saqib Hamid Qazi

Department of Emergency Medicine

Objective: To review the incidence, clinical presentation and outcome of Non traumatic Aortic emergencies in a tertiary care hospital and its evaluation in the Emergency department (ED).
Methods: We conducted a retrospective review of cases presented to the ED at Aga Khan University Hospital during 15 year period (1988 - 2002) who had final diagnosis of Aortic Dissection or Ruptured Aortic Aneurysm. Patients without confirmatory investigations were excluded. We aimed at looking for the incidence, clinical presentation, evaluation in the ED and final outcome.
Results: Of the 12 cases, 7 had aortic dissection while the remaining 5 had ruptured aortic …

Management Outcome Of Residual Common Bile Duct Stones At Aga Khan University Hospital, Muhammad Rizwan Khan, Sameera Naureen, Dildar Hussain, Rizwan Azami

Department of Surgery

Background: The frequency of residual common bile duct (CBD) stones in patients with previous cholecystectomy ranges from 2-10%, and a minimally invasive approach is generally recommended for these patients. This study reviews the experience in the management of residual CBD stones at the Aga Khan University Hospital.Methods: All adult patients diagnosed to have residual CBD stones, from 1993 to 2001, were identified and analyzed in terms of the treatment modality utilized and its associated complications. The role of endoscopic sphincterotomy was particularly analyzed in our set-up.Results: The study population consisted of 66 patients. The mean age was 52 (range:18-84 years) …

Conversion From Laparoscopic To Open Cholecystectomy: Multivariate Analysis Of Preoperative Risk Factors, M Tayeb, S A. Raza, M R. Khan, R Azami

Department of Surgery

Background: Laparoscopic cholecystectomy has become the gold standard in the treatment of symptomatic cholelithiasis. Some patients require conversion to open surgery and several preoperative variables have been identified as risk factors that are helpful in predicting the probability of conversion. However, there is a need to devise a risk-scoring system based on the identified risk factors to (a) predict the risk of conversion preoperatively for selected patients, (b) prepare the patient psychologically, (c) arrange operating schedules accordingly, and (d) minimize the procedure-related cost and help overcome financial constraints, which is a significant problem in developing countries.AIM: This study was aimed …

Female Athletes And Performance-Enhancer Usage, Barbara Kay Fralinger

Seton Hall University Dissertations and Theses (ETDs)

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