Arun K. Srinivasan

Risk factors for sternal wound infection and mid-term survival following coronary artery bypass surgery

OBJECTIVE To identify risk factors for sternal wound infection following coronary artery bypass surgery (CABG), and to compare early and mid-term survival outcome. METHODS Data were prospectively collected for 4228 patients who underwent CABG surgery between April 1997 and March 2001. One hundred and nine (2.6%) patients developed sternal wound infection. We used logistic regression to identify independent risk factors associated with post-operative sternal wound infection. Patient records were linked to the National Strategic Tracing Service, which records all deaths in the UK, to establish current vital status. Deaths occurring over time were described using Kaplan-Meier techniques. To control for differences in patient characteristics, we used Cox proportional hazards analysis to calculate adjusted hazard ratios (HR) and 95% confidence intervals (CI). RESULTS The results of the logistic regression analysis found that the independent predictors of sternal wound infection were obesity (odds ratio (OR) 2.0; P<0.001), New York Heart Association class >/=3 (OR 1.6; P=0.022), use of bilateral internal mammary arteries (OR 3.2; P<0.001), increasing number of grafts (OR 1.5; P<0.001), re-exploration for bleeding (OR 3.1; P=0.011), and increased duration of mechanical ventilation (for every 10 h (OR 1.12; P<0.001)). Three hundred and forty one (8.1%) deaths occurred during the study period with mean follow up of 3.2+/-1.3 years. The crude HR of mid-term mortality for sternal wound infection patients was 2.51 (95% CI 1.59-3.94, P<0.001). After adjustment for pre, intra and post-operative factors, the adjusted HR of mid-term mortality for sternal wound infection patients was 1.64 (95% CI 1.03-2.61, P=0.037). The adjusted freedom from death for sternal wound infections at 30 days, and 1, 2 and 4 years was 96.8, 93.7, 91.4 and 86.7%, respectively, compared with 98.1, 96.1, 94.7 and 91.7% for patients without sternal wound infections. CONCLUSIONS In conclusion, we have identified risk factors for sternal wound infection, many of which are modifiable. We have also shown that there is a significant increase in mortality in patients with sternal wound infection during a 4-year follow-up period after CABG.

Off‐clamp versus complete hilar control laparoscopic partial nephrectomy: comparison by clinical stage

Study Type – Therapy (case series)

Effect of preoperative aspirin use in off-pump coronary artery bypass operations

BACKGROUND The effect of preoperative aspirin use until the day of operation on mortality rate and bleeding risks in patients who had on-pump coronary artery bypass operation has been well documented. However, the effect of aspirin use in patients undergoing off-pump coronary artery bypass operation (OPCAB) with regard to postoperative blood loss and morbidity has not been studied. We aimed to determine the effects of continuing aspirin therapy preoperatively. METHODS We performed a retrospective study of 340 patients who had first-time OPCAB between January 1998 and September 2001. A propensity score for receiving aspirin until the day of operation was constructed from core patient characteristics. All aspirin users (n = 170) were matched with unique 170 nonaspirin users by identical propensity score. The primary outcome measures were in-hospital mortality rate and hemorrhage-related outcomes (postoperative blood loss in the intensive care unit, reexploration for bleeding, and blood product requirements). Secondary outcome measures were stroke, myocardial infarction, gastrointestinal bleeding, and sternal wound infections. RESULTS There were no differences in patient characteristics between aspirin users and nonaspirin users. The average postoperative blood loss (845 mL versus 775 mL; p = 0.157) and the rate of reexploration for bleeding (3.5% versus 3.5%; p > 0.99) were similar in aspirin users and nonaspirin users. We found no significant difference between blood product requirements for the two groups. Similarly, we found no significant difference in the incidence of the secondary outcomes. CONCLUSIONS Preoperative aspirin did not increase bleeding-related complications, mortality rate, or other morbidities in patients who had off-pump coronary artery operation.

Perioperative outcomes of off‐clamp vs complete hilar control laparoscopic partial nephrectomy

Whats known on the subject? and What does the study add?

Comparison of Laparoscopic With Open Approach for Ureterolysis in Patients With Retroperitoneal Fibrosis

PURPOSE The surgical management of retroperitoneal fibrosis has traditionally involved open ureterolysis. We compared laparoscopic and open ureterolysis to determine if the minimally invasive approach offered advantages with respect to perioperative morbidity and treatment efficacy. MATERIALS AND METHODS We reviewed our retroperitoneal fibrosis database at a single institution to identify all patients who underwent open or laparoscopic ureterolysis between 1995 and 2005. Clinical, perioperative and outcome data were prospectively collected and compared between the open and laparoscopic ureterolysis cohorts. Subgroup analysis was performed on patients with primary retroperitoneal fibrosis comparing outcomes in open and laparoscopic ureterolysis groups. RESULTS We identified 36 (51.4%) patients who underwent open ureterolysis and 34 (48.6%) who underwent laparoscopic ureterolysis. Conversion to open surgery was required in 17.6% of the laparoscopic ureterolysis cohort. The etiology of obstruction was primary idiopathic retroperitoneal fibrosis in 35 (50%) patients, whereas the remainder had secondary retroperitoneal fibrosis, largely related to gynecological malignancy. There was no difference between the 2 groups when comparing operative time, estimated blood loss, length of hospital stay, complications, transfusion requirements and postoperative resolution of ureteral obstruction. Subgroup analysis limited to patients with primary idiopathic retroperitoneal fibrosis demonstrated that those who underwent laparoscopic ureterolysis had a shorter hospital stay (3.4 vs 10.8, p <0.001) and were less likely to require transfusion (3.7% vs 13.7%, p = 0.007) compared to patients who underwent open surgery. CONCLUSIONS Laparoscopic ureterolysis is an excellent option for patients with retroperitoneal fibrosis of all causes with morbidity and efficacy comparable to open surgery. In patients with primary idiopathic retroperitoneal fibrosis laparoscopy offers the added advantages of shorter hospital stay and reduced transfusion requirements.

Use of the Valveless Trocar System Reduces Carbon Dioxide Absorption During Laparoscopy When Compared With Standard Trocars

OBJECTIVES To prospectively compare a novel type of valveless trocar that creates a curtain of pressurized carbon dioxide [CO(2)] gas (which maintains pneumoperitoneum at a lower gas flow rate) with standard trocars; to quantify the volume of CO(2) used; and to characterize CO(2) elimination during laparoscopic renal surgery. METHODS A total of 51 patients undergoing laparoscopic renal surgery by a single surgeon were prospectively evaluated using either the valveless trocar (n = 26) or standard trocars (n = 25). Patient demographics, operative time, volume of CO(2) gas consumed, CO(2) elimination, perioperative parameters, and postoperative complications were recorded and analyzed. RESULTS Both patient cohorts were comparable in their preoperative demographics, including body mass index, the number of patients with chronic obstructive pulmonary disease, and smoking history. Mean operative time was lower in the valveless trocar cohort (124.1 minutes) compared with the conventional trocar group (145.6 minutes), P = .047. Use of the valveless trocar was associated with a lower volume of intraoperative CO(2) consumed (120.0 ± 82.8 vs 300.6 ± 191.5; P < .001) and reduced CO(2) elimination compared with standard trocar use after the first 16 minutes of insufflation (P < .05). Minimal complications occurred, including 2 cases of subcutaneous emphysema in the valveless trocar group, and 1 case of respiratory acidosis in the conventional trocar group. CONCLUSIONS Use of a valveless trocar significantly reduced CO(2) consumption during transperitoneal laparoscopy. The valveless trocar also demonstrated significantly reduced CO(2) elimination and absorption when compared with the standard trocar.

History and physical examination findings predictive of testicular torsion: An attempt to promote clinical diagnosis by house staff

OBJECTIVE To standardize the history and physical examination of boys who present with acute scrotum and identify parameters that best predict testicular torsion. MATERIALS AND METHODS Over a 5-month period, a standardized history and physical examination form with 22 items was used for all boys presenting with scrotal pain. Management decisions for radiological evaluation and surgical intervention were based on the results. Data were statistically analyzed in correlation with the eventual diagnosis. RESULTS Of the 79 boys evaluated, 8 (10.1%) had testicular torsion. On univariate analysis, age, worsening pain, nausea/vomiting, severe pain at rest, absence of ipsilateral cremaster reflex, abnormal testicular position and scrotal skin changes were statistically predictive of torsion. After multivariate analysis and adjusting for confounding effect of other co-existing variables, absence of ipsilateral cremaster reflex (P < 0.001), nausea/vomiting (P < 0.05) and scrotal skin changes (P < 0.001) were the only consistent predictive factors of testicular torsion. CONCLUSION An accurate history and physical examination of boys with acute scrotum should be primary in deciding upon further radiographic or surgical evaluation. While several forces have led to less consistent overnight resident staffing, consistent and reliable clinical evaluation of the acute scrotum using a standardized approach should reduce error, improve patient care and potentially reduce health care costs.

Renal Drainage After Percutaneous Nephrolithotomy

Exit strategy after percutaneous nephrolithotomy (PCNL) is an area of continuing innovation to improve postoperative morbidity and operative outcomes for patients. The two important components of an exit strategy after PCNL are hemostasis and renal drainage. We review the different techniques of renal drainage after PCNL-ie, nephrostomy tube, ureteral stents, and totally tubeless strategy with critical discussion of available evidence for and against each of these techniques. We conclude that the optimal renal drainage method depends on patient characteristics and the operative course; hence, it should be individualized. To simplify this, we group patients undergoing PCNL as routine, problematic, and complicated, based on increasing complexity of the procedure and procedural complications. In routine PCNLs, we favor placement of an ureteral stent or a small-bore nephrostomy tube. In problematic and complicated PCNLs, we think the evidence directs toward placement of a nephrostomy tube, small bore being an option in problematic PCNLs.

Long-Term Follow-Up for Salvage Laparoscopic Pyeloplasty After Failed Open Pyeloplasty

OBJECTIVES To report our long-term experience with salvage laparoscopic pyeloplasty after a failed open procedure. Laparoscopic repair of a primary ureteropelvic junction obstruction (UPJO) is associated with very high long-term success. However, there are limited data on patients who have failed previous open pyeloplasty. We have determined that salvage laparoscopic pyeloplasty is an excellent option for these patients. METHODS We queried our laparoscopic pyeloplasty database of 367 patients from July 1994 to May 2007 for patients who had undergone prior open pyeloplasty. We analyzed demographic data, perioperative course, complications, and follow-up studies on identified subjects. We assessed clinical status by verbal pain scale and diagnostic studies. Radiologic follow-up consisted of diuretic renal scan, intravenous pyelography, or both. RESULTS We identified 9 patients (2.5%) who underwent salvage laparoscopic pyeloplasty for persistent obstruction after open pyeloplasty. The mean age of our cohort was 30.5 years (range, 19-50 years). Mean operative time was 204 minutes (range, 80-264 minutes), estimated blood loss was 105 mL (range, 20-300 mL), and mean length of stay was 2.1 days (range, 2-3 days). No intraoperative or postoperative complications were reported. All patients reported relief of symptoms in the immediate postoperative period. At a median follow-up of 66 months (range, 12-119 months), 8 of 9 patients (89%) had clinical and radiologic resolution of UPJO with stable renal function, pain free status, and a patent ureteropelvic junction. The remaining patient failed laparoscopic repair within the first year with evidence of persistent obstruction, necessitating endopyelotomy. CONCLUSIONS Our findings support the use of salvage laparoscopic pyeloplasty as an excellent option for patients who failed previous open pyeloplasty. This approach provides durable long-term outcomes.

Intermediate-Term Followup of Proximal Hypospadias Repair Reveals High Complication Rate

Purpose: Results following distal hypospadias repair are favorable. Grouping proximal and distal hypospadias repair artificially increases the perceived success rate of proximal hypospadias. We identified our complication rate of proximal hypospadias repair and hypothesized a higher complication rate for 1‐stage repair. Materials and Methods: We retrospectively reviewed the records of consecutive boys who underwent proximal hypospadias from 2007 to 2014. Proximal hypospadias was defined as a urethral meatus location at or more proximal than the penoscrotal junction after penile degloving. We further stratified boys into those with planned 1‐stage vs 2‐stage repair. Univariate and Cox regression analyses were performed to assess associations with covariates and compare time to the first complication, respectively. Results: A total of 167 boys met study inclusion criteria. Median followup was 31.7 months for 1‐stage repair in 86 patients and staged repair in 81. The overall complication rate was 56%. Complications developed in 53 of 86 1‐stage (62%) vs 40 of 81 staged (49%) repairs (p = 0.11). The number of unplanned procedures per patient was higher in the 1‐stage than in the staged group (0.99 vs 0.69, p = 0.06), as was the number of patients who had at least 2 complications (29 of 86 or 33% vs 13 of 81 or 16%, p = 0.03). Cox regression showed no difference in time to the first complication for staged compared to 1‐stage repair (HR 0.77, 95% CI 0.43–1.39). Conclusions: Our 56% complication rate of proximal hypospadias warrants further long‐term patient followup. More patients in the 1‐stage group experienced at least 2 complications. However, when complications developed, they developed no differently in the 2 groups.