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Biomedical subjects

Kent W Kercher

Publications and source records attributed to Kent W Kercher.

At least 37 records · Page 2Linked to original sources

Laparoscopic adrenalectomy for malignancy.

The superiority of the minimally invasive approach to adrenal resections has been well documented for benign pathology. With technical advances and increased experience, surgeons have successfully performed laparoscopic adrenalectomies for metastatic and primary malignancies of the adrenal gland. The technique of laparoscopic adrenalectomy as it pertains to malignant lesions is presented. A review of the literature demonstrates the safety and efficacy of laparoscopic adrenalectomy for metastatic colorectal, lung, and renal tumors. For primary adrenal malignancies, radical resections can be effectively performed laparoscopically; however, continued long-term follow-up is needed to establish the minimally invasive technique as the preferred approach.

Adrenal Gland Neoplasms↗

Laparoscopic restoration of intestinal continuity after Hartmann's procedure.

BACKGROUND: Colostomy closure after a Hartmann's procedure typically requires a laparotomy. It also carries the risk of significant morbidity including anastomotic leak, wound infection, and incisional hernia. The aim of this study was to review our experience with laparoscopic restoration of intestinal continuity after Hartmann's procedure. METHODS: After institutional review board approval, we retrospectively reviewed the medical records of patients undergoing laparoscopic colostomy reversal between July 1997 and July 2004. RESULTS: Twenty-two patients were identified; all patients had left colon colostomies. A laparoscopic technique was used in 21 patients, and 1 patient underwent hand-assisted colostomy reversal concurrently with right radical nephrectomy. The laparoscopic approach was successful in 20 cases, and there were 2 conversions to open (9%) secondary to dense adhesions around the rectal stump. The mean time to closure of the colostomy was 168 days (range 69-385 days). The mean operative time was 158 minutes (range 84-356 minutes). The estimated blood loss averaged 114 mL (range 30-250 mL). The average length of hospitalization was 4.2 days (range 2-6 days). Bowel function returned on an average of 3.5 days (range 2-5 days). Three patients (14%) developed postoperative wound infections. There were no anastomotic leaks and no mortality. At a mean follow-up of 14.7 months, the only long-term complication has been a small hernia at a colostomy site. CONCLUSIONS: Laparoscopic colostomy reversal after Hartmann's procedure can be performed with low morbidity and a short hospital stay. The need for conversion to open surgery is uncommon despite patients' previous surgeries. A laparoscopic approach to colostomy takedown is safe and feasible and may result in a reduction in complications and length of stay as has been seen with other minimally invasive procedures.

Adult↗

Evaluation of adhesion formation and host tissue response to intra-abdominal polytetrafluoroethylene mesh and composite prosthetic mesh.

BACKGROUND: The purpose of this study was to measure the extent of adhesion formation to ePTFE mesh (DualMesh, W.L. Gore & Associates, Inc, Flagstaff, AZ) and two composite prosthetic materials, ePTFE and polypropylene (Bard Composix, C.R. Bard, Inc, Murray Hill, NJ) and hyaluronic acid/carboxymethylcellulose and polypropylene (Sepramesh, Genzyme Corp, Cambridge, MA) after their intra-abdominal placement on an intact peritoneum, simulating laparoscopic ventral hernia repair, and to evaluate host tissue response to the prosthetic biomaterials. MATERIALS AND METHODS: Through a midline laparotomy, a 2 x 2 cm piece of mesh (n = 60) was sewn to an intact peritoneum on each side of a midline incision in 30 New Zealand white rabbits. Mesh adhesions were scored using a modified Diamond scale (0 = 0%, 1 = 1-25%, 2 = 26-50%, 3 >50%) at 1, 3, 9, and 16 weeks by serial microlaparoscopy (2 mm). All laparoscopic evaluations were videotaped for blinded scoring by three surgeons. Host tissue response was graded (1-4) for inflammation, tissue ingrowth, and mesothelialization. The predominant cell type (polymorphonuclear leukocytes versus foreign body giant cell) was recorded. Statistical differences (P value <0.05*) were measured using a two-tailed t test and Kruskal-Wallis test. RESULTS: The mean adhesion score was significantly (P < 0.001) less for ePTFE mesh at 1, 3, 9, and 16 weeks compared with the two composite prosthetic materials. There were no differences in the mean adhesion scores between the two biosurgical composite meshes at any of the time intervals. There were no differences in the mean score for inflammation, tissue ingrowth and mesothelialization between any of the prosthetic biomaterials. The predominant cell type on all histological evaluations was polymorphonuclear leukocytes. CONCLUSIONS: Placing ePTFE mesh (DualMesh) intra-abdominal against an intact peritoneum results in significantly fewer adhesions than the composite prosthetic meshes during a 4-month follow-up. The host tissue response is equivalent for the three prosthetic biomaterials. The long-term consequences of increased adhesion formation to the composite meshes and the ultimate biocompatibility of the nonabsorbable and absorbable barriers on the polypropylene mesh are to be determined.

Abdomen↗

Laparoscopic repair of incisional hernias.

Laparoscopic repair of incisional hernia has been shown safe and efficacious, with low rates of conversion to open, short hospital stay, moderate complication rate, and low recurrence. Using the benefits of open retromuscular, sublay repair, the laparoscopic approach provides adequate mesh overlap and allows for identification of the entire abdominal wall fascia at risk for hernia formation. Fixation of the prosthesis to the abdominal wall is best provided by transabdominal to secure the mesh during the initial phase of incorporation. Long-term follow-up data support the durability of laparoscopic repair of ventral hernias with reduced rate of recurrence, low risk of infection, and applicability to difficult patient populations, such as the morbidly obese and those with prior failed attempts.

Abdominal Wall↗

Clinical outcomes of laparoscopic adrenalectomy for lateralizing nodular hyperplasia.

BACKGROUND: Nodular adrenal hyperplasia (NAH) may mimic the biochemical characteristics of an aldosterone-producing adenoma. The authors evaluated the outcomes of unilateral laparoscopic adrenalectomy in the setting of lateralizing aldosterone hypersecretion by NAH. METHODS: Retrospective review of consecutive patients who underwent a laparoscopic adrenalectomy for primary hyperaldosteronism owing to NAH was performed. Patient demographics, perioperative symptoms, medications, radiographic findings, and serum chemistries were analyzed. Response to operation was classified according to postoperative control of hypertension and hypokalemia as resolved, improved, or refractory. RESULTS: From January 1999 to October 2004, 15 patients underwent a laparoscopic unilateral adrenalectomy for hyperaldosteronism owing to lateralizing NAH. Nine (60%) patients presented with > or =5 years of hypertension, including 8 (53%) patients with labile or malignant hypertension. Ten (67%) patients had hypokalemia. Abdominal imaging results were normal in 9 (60%) patients. All patients underwent adrenal venous sampling (94% successfully), which revealed an average adjusted aldosterone ratio of 17.6 (range, 1.2 to 75.9). At a mean follow-up of 26 (range, 4 to 58) months, hypertension had resolved in 4 (27%), improved in 8 (53%), and was refractory in 3 (20%) patients. Hypokalemia resolved in all patients. There were no complications, conversions, or mortalities. CONCLUSION: This series shows that unilateral adrenalectomy for lateralizing NAH results in eradication of hypokalemia and resolution or significant improvement in hypertension in 80% of patients at long-term follow-up. When lateralization of aldosterone production is noted, laparoscopic adrenalectomy provides significant clinical improvement even in patients with a pathologic diagnosis of NAH.

Adrenal Glands↗

Gas embolism during laparoscopic cholecystectomy.

Advancements in laparoscopic surgery have resulted in decreased length of hospitalization, reduced postoperative pain, and better cosmesis following general surgical procedures. Carbon dioxide gas embolism is a rare occurrence that can be fatal. We report the case of a patient with a venous gas embolism during laparoscopic cholecystectomy. A 63-year-old woman presented with intermittent right upper quadrant pain, and her abdominal ultrasound showed a possible gallbladder polyp. A laparoscopic cholecystectomy was planned. A Veress needle was placed in the right upper quadrant to initiate abdominal access. Shortly after carbon dioxide insufflation, the patient's hemodynamic status deteriorated, her oxygen saturation dropped, and her end-tidal CO2 decreased. Gas insufflation was immediately stopped, and the patient was resuscitated. She stabilized quickly, and the procedure was performed without further event. She did well postoperatively and was discharged home the next day. Carbon dioxide embolism during laparoscopy, albeit rare, can be a fatal complication of the procedure. Whenever sudden changes in hemodynamic stability occur, venous gas embolism should be considered. As laparoscopic techniques and applications are expanded, the general surgeon must be aware of this entity.

Carbon Dioxide↗

Laparoscopic curative resection of pheochromocytomas.

PURPOSE: Pheochromocytomas are relatively uncommon tumors whose operative resection has clear medical and technical challenges. While the safety and efficacy of laparoscopic adrenalectomy are relatively well documented, few studies with extended follow-up have been conducted to measure the success of the procedure for the most challenging of the adrenal tumors. In addition, several reports question the applicability of a minimally invasive approach for sizeable pheochromocytomas. The purpose of our investigation was to assess the outcomes of laparoscopic adrenalectomy for pheochromocytomas in the largest study to date when performed by experienced laparoscopic surgeons. METHODS: All pheochromocytomas removed by the authors from January 1995 to October 2004 were reviewed under an Institutional Review Board approved protocol. Eighty-five percent were documented in a prospective fashion. RESULTS: Eighty consecutive patients underwent laparoscopic resection of 81 pheochromocytomas. Seventy-nine were found in the adrenal (42 left, 35 right, 1 bilateral); 2 were extra-adrenal paragangliomas. Eight patients had multiple endocrine neoplasia syndrome. Two lesions were malignant. There were 48 females and 32 males with a mean age of 45 years (range, 15-79 years). Mean tumor size was 5.0 cm (range, 2-12.1 cm); 41 of these lesions were 5 cm in size or larger. Average operative time and blood loss were 169 minutes (range, 69-375 minutes) and 97 mL (range, 20-500 mL), respectively. Intraoperative hypertension (systolic blood pressure, >170 mm Hg) was reported in 53% of patients and hypotension (systolic blood pressure, <90 mm Hg) in 28% of patients. There were no conversions to open surgery. Mean length of stay was 2.3 days (range, 1-10 days). There were 6 perioperative morbidities (7.5%) and no mortalities. No patient required a blood transfusion. No recurrence of endocrinopathy has been documented at a mean follow-up of 21.4 months. CONCLUSION: Laparoscopic resection of pheochromocytomas, including large lesions, can be accomplished safely by experienced surgeons. A short hospital stay with minimal operative morbidity and eradication of endocrinopathy support the minimally invasive approach for adrenalectomy in the setting of pheochromocytoma.

Adolescent↗

The argument for lightweight polypropylene mesh in hernia repair.

The development of polypropylene prosthetics revolutionized surgery for the repair of abdominal wall hernias. A tension-free mesh technique has drastically reduced recurrence rates for all hernias compared to tissue repairs and has made it possible to reconstruct large ventral defects that were previously irreparable. The repair of abdominal wall defects is one of the most commonly performed general surgical procedures, with over 1 million polypropylene implants inserted each year. Surprisingly, little research has been performed to investigate the interaction of abdominal wall forces on a ventral hernia repair or the required amount or strength of the foreign-body material necessary for an adequate hernia repair. The long-term consequences of implantable polypropylene prosthetics are not without concern. The body generates an intense inflammatory response to the prosthetic that results in scar plate formation, increased stiffness of the abdominal wall, and shrinkage of the biomaterial. Reducing the density of polypropylene and creating a ''light weight'' mesh theoretically induces less foreign-body response, results in improved abdominal wall compliance, causes less contraction or shrinkage of the mesh, and allows for better tissue incorporation. A review of the laboratory data and short-term clinical follow-up is reviewed to provide a strong basis or argument for the use of ''light weight'' prosthetics in hernia surgery.

Dioxanes↗

Evaluation of the efficacy of the electrosurgical bipolar vessel sealer (LigaSure) devices in sealing lymphatic vessels.

Various sources of ultrasonic and thermal energy have been developed to facilitate blood vessel ligation. However, their efficacy in sealing lymphatics has not been clearly established to date. We hypothesized that the electrosurgical bipolar vessel sealer (EBVS) produces reliable and durable sealing of large lymphatic vessels in a porcine model. Thoracic ducts from 4 adult pigs were explanted and sealed at multiple levels by using 3 different EBVS devices: LigaSure Atlas, XTD, and V. Fifteen seals (5 per group) were analyzed for sealing time and visual quality. Seal burst strength was measured by using a graduated pressure saline injection system. Twelve intact seals also underwent a histologic analysis. The mean overall burst strength of the seals was 271+/-78 mm Hg (127 to 360 mm Hg). The burst pressures in the 3 groups were not statistically different. The overall mean time to achieve a seal was 5.1+/-2.2 seconds (3 to 10 seconds). Seals were achieved significantly faster in the V group (4.1+/-0.6 seconds) compared with the Atlas (6.3+/-2.3 seconds) and XTD (6.4+/-2.6 seconds) groups. Qualitative seal assessment revealed minimal sticking and charring, a favorable degree of seal tissue clarity, and desiccation in the 3 groups. Histologic analysis demonstrated a fusion of lymphovascular channels with a complete obliteration of the lumens. We demonstrated that the use of EBVS results in a fast and effective sealing of large porcine lymphatic vessels. The seals created by all 3 devices burst at markedly supraphysiologic intraluminal pressures. Ongoing randomized human trials may prove the clinical benefits of the routine use of EBVS devices for various tissue dissections.

Animals↗

National study of the effect of patient and hospital characteristics on bariatric surgery outcomes.

The influence of patient and hospital demographics on gastric bypass (GB) outcomes is unknown. We analyzed year 2000 data from the Nationwide Inpatient Sample database for all GB patients. In 2000, 5876 GB were performed in the 137 sample hospitals (M:F, 14%:86%). Length of stay (LOS, days), charges, comorbidities, and morbidity were higher for those aged >60 years compared to < 40 years. LOS, charges, comorbidities, morbidity, and mortality were highest in males. LOS was longest in African Americans compared to Caucasians and Hispanics. Charges and comorbidities were greatest in African Americans and Hispanics compared to Caucasians. Medicare and Medicaid-insured patients have higher LOS, charges, comorbidities, morbidity, and mortality compared to privately insured and self-pay patients. Lower income patients have higher LOS and total charges. Nonteaching hospitals have an increased LOS and charges and treat patients with more comorbidities compared to teaching hospitals. LOS, charges, and morbidity are directly proportional to hospital size. Urban hospitals have lower LOS and higher charges compared to rural hospitals. As hospital GB volume increases, LOS, charges, and morbidity decrease with no mortality effect. After controlling for all other covariates, male gender, increased age, and large hospital size were predictors of increased morbidity. Having had a complication predicted increased mortality, while female gender had a protective effect. Patient income, insurance status, and race did not play a role in morbidity or mortality. Neither academic, teaching status of the hospital or hospital gastric bypass volume influenced patient outcomes. Patient and hospital demographics do affect the outcomes of patients undergoing GB. Increasing age, male gender, and surgery performed in large hospitals are predictors of morbidity. Male gender and postoperative complications predict increased mortality. Neither comorbidities, race, payer, income, hospital academic status, location, nor hospital volume affect the outcome after GB.

Adult↗

Prospective, blinded evaluation of accuracy of operative reports dictated by surgical residents.

Incomplete or inaccurate operative notes result in delayed, reduced, or denied reimbursement. Deficient reports may be more common when dictated by the surgical residents. We performed a blinded study to assess the accuracy of residents' dictations and their effect on the appropriate level of coding for reimbursement. A prospective, blinded study was performed comparing operative reports dictated by senior surgical residents (postgraduate years 3, 4, and 5) to reports dictated by attending surgeons. All residents had previously undergone group instruction on the importance and structure of operative notes. The trainees were blinded to the fact that the attending surgeons were dictating the operative reports on a separate dictation system. The dictations were analyzed by faculty reimbursement billing personnel for accuracy and completeness. Fifty operative reports of general surgical procedures dictated by both surgical residents and attending physicians were reviewed. A total of 97 CPT codes were used to report services rendered. Residents' dictations resulted in incorrect coding in 14 cases (28% error rate). The types of inaccuracies were a completely missed procedure (4) and insufficient documentation for an appropriate CPT code and/or modifier (10). All deficiencies occurred in complex, multicode, and/or laparoscopic cases. Sixty-seven per cent of late dictations were incomplete. The financial analysis revealed that deficiencies in resident dictations would have reduced the reimbursement by $18,200 (9.7%). For cases with deficient dictations, 29.5 per cent of charges would have been missed, delayed, or denied if the resident-dictated note was used to justify charges. Operative reports dictated by surgical residents are often incomplete or inaccurate, likely leading to reduced or delayed reimbursement. Dictations of complex, multicode, or laparoscopic surgeries, especially if delayed beyond 24 hours, are likely to contain significant deficiencies that affect billing. Attending surgeons may be better equipped to dictate complex cases. Formal housestaff education, mentorship by the attending faculty, and ongoing quality control may be paramount to minimize documentation errors to ensure appropriate coding for the services rendered.

Current Procedural Terminology↗

Optimal closure method of five-millimeter trocar sites.

BACKGROUND: Although many surgeons use absorbable sutures for skin closure of 5-mm trocar sites, effective alternative materials exist. We compared 5-mm trocar site closures using a vicryl suture (VS), cyanoacrylate tissue adhesive (CTA), or skin tape (ST). METHODS: Patients rated wound pain and appearance at 1 and 6 weeks after surgery. Seven surgeons masked to the closure method rated wound photographs at these time points using the Hollander wound evaluation scale. Logistic regression analysis was used to evaluate the ratings of each closure group. RESULTS: The 137 wounds of 48 patients undergoing laparoscopic procedures were randomized among three closure method groups. Patient demographics and procedure type were similar for all groups. Long closure times (>30 seconds) was significantly higher for VS compared with CTA and ST. Patients favored VS over ST and CTA at 1 week with respect to pain and wound appearance (P = 0.04 and P = 0.02, respectively). They rated CTA closures more likely to have pain and poor wound appearance at 6 weeks (P = 0.05 and P = 0.03, respectively). Surgeons rated VS less likely (P = 0.02) and CTA more likely (P = 0.003) to show moderate to severe scar formation. Vicryl suture was less likely to have wound separation and edge inversion (P = 0.017 and P = 0.006, respectively). Cyanoacrylate tissue adhesive was more likely to yield step-off (P = 0.03), contour irregularities (P = 0.005), separation (P = 0.004), excessive distortion (P = 0.001), and edge inversion (P = 0.03). CONCLUSIONS: Although VS closure time of 5-mm trocar sites takes longer than CTA and ST, VS scar formation and comfort is superior to CTA and ST. Cyanoacrylate tissue adhesive yields poor results with respect to both wound healing and pain.

Equipment Design↗

Laparoscopic splenectomy reverses thrombocytopenia in patients with hepatitis C cirrhosis and portal hypertension.

Pegylated-interferon (IFN) plus ribavirin remains the most effective therapeutic regimen for patients with chronic hepatitis C infection. Thrombocytopenia is a common side effect of this treatment, often leading to discontinuation of a potentially curative therapy. We sought to determine the safety and efficacy of laparoscopic splenectomy in correcting thrombocytopenia, thus allowing completion of IFN therapy. Data were collected prospectively from September 2000 to May 2003 on all patients undergoing laparoscopic splenectomy for thrombocytopenia associated with IFN therapy and/or hepatitis C cirrhosis with portal hypertension. Demographic data, model of end-stage liver disease (MELD) score, platelet count, operative time, blood loss, spleen weight, complications, length of stay, and follow-up time were calculated. Eleven patients (7 men, 4 women) underwent laparoscopic splenectomy; their mean age was 45.4 years (range 27 to 55 years) and mean body mass index was 27 kg/m(2) (range 21 to 44 kg/m(2)). All patients were Child's class A, with a mean preoperative MELD score of 9.1 (range 6 to 11). Mean operative time was 189 minutes (range 70 to 245 minutes), and blood loss averaged 141 ml (range 10 to 600 ml). A hand-assisted laparoscopic technique was used in four cases. Six patients received empiric intraoperative platelet administration. None required transfusion with packed red cells. Splenic weight averaged 1043 g (range 245 to 1650 g). Average length of stay was 2.6 days (range 1 to 6 days). Four patients had the following minor postoperative complications: self-limited atrial fibrillation (n=1), trocar site cellulitis (n=1), and atelectasis (n=2). There have been no major complications over an average follow-up of 11 months (range 1 to 18 months). Mean postoperative MELD score was 8.3 (range 6 to 10). Platelet counts improved from a preoperative mean of 55000/ul (16000 to 88000/microl) to 439000/microl (200000 to 710000/microl) postoperatively and have remained above 100000/microl (104000 to 397000/microl) during subsequent pegylated-IFN therapy. Three patients have completed a full course of IFN therapy and have obtained a sustained virologic response. Treatment is ongoing in the remaining patients. Laparoscopic splenectomy is safe in the setting of portal hypertension and thrombocytopenia associated with chronic hepatitis C infection. It can be performed with little blood loss, no need for red cell transfusion, and minimal perioperative morbidity. Laparoscopic splenectomy appears to effectively reverse thrombocytopenia and may allow these patients to safely complete IFN therapy.

Adult↗

Laparoscopic splenectomy for splenic abscess.

Splenic abscess is a rare clinical entity, and splenectomy remains the treatment of choice. We sought to determine the safety and efficacy of laparoscopic splenectomy in this setting. Using a prospective database of laparoscopic splenectomy, we identified 4 patients who underwent surgery for splenic abscess (3 male, 1 female). Mean age was 55.5 (range 42-78) years. Patient symptoms included: fever and abdominal pain in 4 patients, pleural effusions in 2, and nausea and leukocytosis in 1. Risk factors for splenic abscess included septic emboli from bacterial endocarditis in 2 patients and acquired immune deficiency syndrome in 1. All patients underwent successful laparoscopic splenectomy. Mean operative time was 200 (range 160-220) minutes, and blood loss was 220 (range 100-450) mL. There were no postoperative complications or deaths; postoperative length of stay averaged 14 (range 2-26) days. Despite the difficulty of the operation, the laparoscopic approach appears to be a safe and effective treatment of splenic abscess.

Abscess↗

Surgical treatment of achalasia in the 21st century.

BACKGROUND: Achalasia is a primary motility disorder of the esophagus characterized by poor mid-esophageal motility and failure of the lower esophageal sphincter to properly relax. The optimal treatment of the disease would improve esophageal peristalsis and promote lower esophageal sphincter relaxation. Currently, such therapy is not possible, so treatment of the disorder is aimed at relief of symptoms by disruption of the lower esophageal sphincter. METHODS: Data were collected prospectively on all patients undergoing laparoscopic myotomy and Toupet fundoplication during a 6-year period. RESULTS: Fifty-nine patients with a mean age of 44 years were treated during a 6-year period. Fifty-three patients underwent laparoscopic myotomy with Toupet fundoplication (91%), and four had laparoscopic myotomy without a fundoplication (6%). Fundoplication was not performed in two patients who had a megaesophagus. Two patients required conversion to an open operation. Sixty percent of patients were discharged the day after surgery; the average length of stay for all patients was 2.1 days. Ten percent of patients had minor complications; none required reoperation. Mortality was 0%, and 96% of patients rated their postoperative swallowing ability as excellent or good. CONCLUSION: Surgical myotomy is becoming first-line therapy for all patients with achalasia. A strong working relationship between surgeon and gastroenterologist helps to optimize patient care.

Adult↗

Energy sources in laparoscopy.

Traditional monopolar and bipolar electrosurgery remain very useful in laparoscopic surgery. The need for meticulous hemostasis and the tedium of vessel ligation in advanced cases has propelled the development of new energy source devices that have proved to be remarkably helpful in both laparoscopic and open surgery. Energy sources in the form of argon beam coagulation, ultrasonic coagulation, and bipolar vessel sealing systems have revolutionized laparoscopic surgery. Although each of these energy sources has improved the efficiency and safety of minimally invasive techniques, they can also be associated with distressing complications. This report describes the biophysics of these tools, their spectrum of effectiveness, and methods of application that may improve our ability to perform surgery in a safe and proficient manner.

Argon↗