Steatorrhea and Hyperoxaluria in Severely Obese Patients Before and After Roux-en-Y Gastric Bypass.

BACKGROUND AND AIMS: Hyperoxaluria after Roux-en-Y gastric bypass (RYGB) is generally attributed to fat malabsorption. If hyperoxaluria is indeed caused by fat malabsorption, magnitudes of hyperoxaluria and steatorrhea should correlate. Severely obese patients, prior to bypass, ingest excess dietary fat that can produce hyperphagic steatorrhea. The primary objective of the study was to determine whether urine oxalate excretion correlates with elements of fat balance in severely obese patients before and after RYGB. METHODS: Fat balance and urine oxalate excretion were measured simultaneously in 26 severely obese patients before and 1 year after RYGB, while patients consumed their usual diet. At these time points, stool and urine samples were collected. Steatorrhea and hyperoxaluria were defined as fecal fat >7 g/day and urine oxalate >40 mg/day. Differences were evaluated using paired 2-tailed t tests. RESULTS: Prior to RYGB, 12 of 26 patients had mild to moderate steatorrhea. Average urine oxalate excretion was 61 mg/day; there was no correlation between fecal fat and urine oxalate excretion. After RYGB, 24 of 26 patients had steatorrhea and urine oxalate excretion averaged 69 mg/day, with a positive correlation between fecal fat and urine oxalate excretions (r = 0.71, P < .001). For each 10 g/day increase in fecal fat output, fecal water excretion increased only 46 mL/day. CONCLUSIONS: Steatorrhea and hyperoxaluria were common in obese patients before bypass, but hyperoxaluria was not caused by excess unabsorbed fatty acids. Hyperphagia, obesity, or metabolic syndrome could have produced this previously unrecognized hyperoxaluric state by stimulating absorption or endogenous synthesis of oxalate. Hyperoxaluria after RYGB correlated with steatorrhea and was presumably caused by excess fatty acids in the intestinal lumen. Because post-bypass steatorrhea caused little increase in fecal water excretion, most patients with steatorrhea did not consider themselves to have diarrhea. Before and after RYGB, high oxalate intake contributed to the severity of hyperoxaluria.

Surgical weight loss >65 years old: is it worth the risk?

BACKGROUND: Weight loss surgery in patients >65 years old has been underused, secondary to the morbidity and mortality concerns of healthcare providers. Comparative outcomes analyses of this patient population have been lacking. The purpose of the present report was to evaluate the safety and outcome of gastric bypass in patients >65 years of age. METHODS: A prospective database was used to analyze the safety, operative morbidity, and outcome. All patients undergoing surgery since January 2005 were included. RESULTS: The analysis of 1474 patients demonstrated a greater operative risk profile for patients >65 years (n = 100) compared with those <65 years old (n = 1374) related to sleep apnea (45% versus 34%), diabetes mellitus (65% versus 33%), and hypertension (81% versus 57%). The operative outcomes were similar for the 2 groups as determined by the operative time (70 versus 65 minutes), length of stay (1.97 versus 1.3 days), and 30-day readmission rate (6.0% versus 7.4%). The postoperative complication rates were low in the patients >65 years old (bleeding 1.0%, pulmonary 3.0%, cardiac 2.0%, wound 2.0%, and 30-day mortality rate 0%). The percentage of excess body weight loss in the gastric bypass patients was similar between the patients >65 years old and those <65 years old at 12 months (74.8% versus 77.8%) and 24 months (83.4% versus 78.5%). CONCLUSION: Our experience represents one of the largest series of laparoscopic gastric bypass in elderly patients. The data have demonstrated excellent outcomes compared with a younger population.

The contribution of malabsorption to the reduction in net energy absorption after long-limb Roux-en-Y gastric bypass.

BACKGROUND: Roux-en-Y gastric bypass (RYGB) restricts food intake, and when the Roux limb is elongated to 150 cm, the procedure is believed to induce malabsorption. OBJECTIVE: Our objective was to measure total reduction in intestinal absorption of combustible energy after RYGB and the extent to which this was due to restriction of food intake or malabsorption of ingested macronutrients. DESIGN: Long-limb RYGB was performed in 9 severely obese patients. Dietary intake and intestinal absorption of fat, protein, carbohydrate, and combustible energy were measured before and at 2 intervals after bypass. By using coefficients of absorption to measure absorptive function, equations were developed to calculate the daily gram and kilocalorie quantities of ingested macronutrients that were not absorbed because of malabsorption or restricted food intake. RESULTS: Coefficients of fat absorption were 92 ± 1.3% before bypass, 72 ± 5.5% 5 mo after bypass, and 68 ± 8.7% 14 mo after bypass. There were no statistically significant effects of RYGB on protein or carbohydrate absorption coefficients, although protein coefficients decreased substantially in some patients. Five months after bypass, malabsorption reduced absorption of combustible energy by 124 ± 57 kcal/d, whereas restriction of food intake reduced energy absorption by 2062 ± 271 kcal/d. Fourteen months after bypass, malabsorption reduced energy absorption by 172 ± 60 kcal/d compared with 1418 ± 171 kcal/d caused by restricted food intake. CONCLUSION: On average, malabsorption accounted for ≈6% and 11% of the total reduction in combustible energy absorption at 5 and 14 mo, respectively, after this gastric bypass procedure.

Operative probe scintimetry with indium and technetium for colorectal cancer.

Surgeons introduced the hand-held gamma detection probe in combination with tumor-directed monoclonal antibodies in patients with colorectal cancer. The clinicians conducted innovative research involving antibody chemistry and variation as well as radioactive dosimetry and decay. The results of these studies represented an era when surgeons began reporting on specific lesion detection and the impact of the antibody administration on the management of the patient. The summary of the important early trials involving monoclonal antibodies and probe scintimetry provides a valuable look into the early development of the antibody technology and a glimpse of potential future applications using the gamma detection probe.

The utility of capsule endoscopy and its role for diagnosing pathology in the gastrointestinal tract.

BACKGROUND: Capsule endoscopy (CE) is a new device that enables visualization of areas of the small bowel that were previously inaccessible through other noninvasive procedures. The purpose of this study is to evaluate this new diagnostic tool and its efficacy in finding occult GI tract pathology. METHODS: A single-institution retrospective review was completed on patients undergoing CE from January 2002 to September 2004. Data evaluated included indications for CE, results of previous studies, CE findings, and complications of the CE study. RESULTS: A total of 702 CE studies in 652 patients were performed during the study period. Suspicious GI bleeding presenting as anemia, guaiac positive stools, or history of gross bleeding were the most common reasons to perform CE (75.8%). Other indications included abdominal pain (11.5%), diarrhea (3.1%), or others (9.5%). In studies performed for GI bleeding (N = 532), a source was found in 49.3% of CE studies. Arteriovenous malformation (AVM) was the most common reported finding (43.9%), followed by ulcer (24.1%), colon or gastric pathology (14.1%), mass/tumor (9.1%), and stricture (6.9%). Patients with abdominal pain (n = 81) had findings 46.9% of the time including edema/ulcer (47.4%), stricture (10.5%), mass/tumor (26.3%), gastric pathology (10.5%), AVM (2.6%), or sprue (2.6%). Patients with diarrhea (n = 22) had findings 45.5% of the time including edema/ulcer (75%), mass/tumor (12.5%), or sprue (12.5%). A total of 66 patients underwent operative exploration after a CE study at this institution either because of the observed findings or for other reasons. There were 12 (1.7%) CE studies in which the capsule was retained and required surgical removal. Pathology at the retention site included benign strictures or adhesions (n = 9, 75%), Crohn's stricture (n = 1, 8.3%) carcinoid tumor (n = 1, 8.3%), and villous adenoma (n = 1, 8.3%). CONCLUSIONS: CE is an accurate study to locate abnormalities in the GI tract that may have either been missed by previous diagnostic studies or cannot be observed through other non-invasive means. When used for diagnostic challenges such as GI bleeding with no apparent source, CE can be helpful in guiding surgical decisions in patients and thus should be integrated as part of the diagnostic workup.

Survival analysis following sentinel lymph node biopsy: a validation trial demonstrating its accuracy in staging early breast cancer.

Few long-term follow-up studies prove sentinel lymph node biopsy (SLNB) effectively stages breast cancer without the further evaluation of a completion axillary dissection. Our prospective study addressed this issue, enrolling 345 women with clinically node-negative breast cancer who underwent SLNB from October 1997 through December 2000. The median age of the patients in the study was 56.7 years. Average primary tumor size was 1.42 cm. Ninety-three patients had a positive sentinel lymph node (27%); 70 (75.3%) of these patients underwent completion axillary dissection, while 23 patients (24.7%) declined further surgery. Most (91.3%) of the patients who declined further surgery had evidence of micrometastatic disease only. The median follow-up period for all patients was 60 months. No tumor recurrences in the axilla were reported in either sentinel node-negative or -positive patients. The local and systemic recurrence rates were 3.1% and 4% in node-negative patients and 2.2% and 4.3% in node-positive patients. Two patients (0.9%) in the node-negative group and 6 (6.5%) in the node-positive group died of their disease. Estimated 5-year disease-free survival rates were 96% for node-negative patients and 87% for node-positive patients (P = 0.02). The clinical false-negative rate of the SLNB in this study was 0%. This long-term validation trial proves the accuracy of the SLNB and its extremely low false-negative rate. The findings indicate that patients with a positive SLNB have significantly different survival rates than patients with a negative SLNB.

Usefulness of endoscopic ultrasound in patients at high risk of choledocholithiasis.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) has been considered the nonsurgical gold standard for the diagnosis and treatment of choledocholithiasis (CDL). Complications include a 0.1% to 1.3% mortality rate and a 5% to 19% morbidity rate, including a reported 1.8% to 6.7% incidence of postprocedure pancreatitis. Twenty-seven percent to 67% of ERCPs done for suspected choledocholithiasis ultimately have negative results. Endoscopic ultrasound (EUS) has been proposed as an alternate means of diagnosing choledocholithiasis that may eliminate the need for ERCP and its associated morbidities in certain patients. METHODS: Retrospective chart review identified 30 patients who underwent EUS with or without ERCP for suspected choledocholithiasis. Reports of all procedures performed were obtained and data were collected on all biliary abnormalities identified on both EUS and ERCP. RESULTS: Pancreaticobiliary abnormalities were identified in 27 of 30 patients (90%) at EUS. Most common diagnoses included CDL (n = 9, 30%), biliary sludge (n = 11, 37%), pancreatitis (n = 8, 27%), and cholelithiasis (n = 7, 23%). Subsequent ERCP was performed in 14 patients (47%). Indications included a diagnosis of CDL by EUS (n = 9) and abnormal liver function tests (n = 5). CDL was identified in 5 of 14 patients (36%), and microlithiasis/biliary sludge was identified in an additional 5 patients (36%). In 4 patients, CDL was identified by EUS but not by ERCP. ERCP did not identify any new cases of CDL after EUS: of 21 patients without evidence of CDL on EUS, none were subsequently shown to have CDL or to develop any complications related to common duct stones. CONCLUSIONS: EUS is an effective method of diagnosing CDL. It demonstrates both a high sensitivity and specificity for identifying common bile duct stones. Its use as a screening modality in patients suspected of having CDL may allow more selective use of ERCP.

Validation study of intraoperative fine-needle aspiration of parathyroid tissue with measurement of parathyroid hormone levels using the rapid intraoperative assay.

BACKGROUND: Surgical treatment of hyperparathyroidism relies on the ability to accurately identify parathyroid tissue. The use of intraoperative fine-needle aspiration (FNA) with measurement of intact parathyroid hormone level (iPTH-FNA) has been suggested as a useful adjunct and is evaluated in this pilot study. METHODS: An institutional review board-approved retrospective review was performed on patients undergoing parathyroid exploration for primary hyperparathyroidism who also underwent selective FNA at the end of the procedure. FNA was performed on excised parathyroid tissue, ipsilateral thyroid tissue, and muscle. RESULTS: Ten patients underwent FNA. Mean iPTH-FNA values were 1559.6 pg/mL (range, 675-1775) for parathyroid, 51.4 pg/mL(range, 10-248) for thyroid, and 34.1 pg/mL (range, 14-128) for muscle. All iPTH-FNA assay results were significantly higher for parathyroid tissue than for either thyroid tissue (P < 0.05) or muscle (P < 0.05). There were no significant iPTH-FNA assay differences between thyroid and muscle (P = 0.09). CONCLUSIONS: Intraoperative FNA of parathyroid tissue with the rapid iPTH assay can correctly identify parathyroid tissue. It may prove to be a useful surgical adjunct in the treatment of hyperparathyroidism.

Optimizing outcomes in bariatric surgery: outpatient laparoscopic gastric bypass.

BACKGROUND: Roux-en-Y gastric bypass (RYGB) is an effective treatment of severe obesity and one of the fastest growing surgical procedures in the United States. METHODS: A single institution prospective database of patients undergoing outpatient laparoscopic (lap) RYGB over a 3-year period was reviewed. Study end points included hospital discharge within 23 hours, 30-day hospital readmission rate, early (<30 day) and late complication rates, and 30-day perioperative mortality. Variables assessed included surgeon experience, patient demographics, comorbidities, operative time, Roux limb pathway, intraoperative steroid bolus, and use of dexmedetomidine. RESULTS: Two thousand consecutive patients undergoing outpatient lap RYGB were identified, and 84% (n = 1669) were discharged within 23 hours. Of these, 1.7% (n = 34) were readmitted within 30 days. The overall early and late complication rates were 1.9% (n = 38) and 4.3% (n = 86), respectively. The 30-day mortality rate was 0.1% (n = 2), and neither patient was discharged before death. Univariate analysis demonstrated surgeon experience (<50 cases), age (<56 years), body mass index (<60 kg/m), weight (400 lbs), comorbidities (<5), and intraoperative steroid bolus as predictive of successful outpatient discharge. Multivariate analysis revealed surgeon experience, comorbidities, body mass index, and steroid bolus as predictive variables. CONCLUSIONS: These data suggest that outpatient lap RYGB can be performed with acceptable perioperative complication rates, hospital readmission, and mortality rates. Surgeon experience, careful patient selection, and the use of intraoperative steroid bolus predicted optimal patient outcomes.

TNFerade, an adenovector carrying the transgene for human tumor necrosis factor alpha, for patients with advanced solid tumors: surgical experience and long-term follow-up.

BACKGROUND: Over the last several years, attempts have been made to use the tumoricidal effects of tumor necrosis factor (TNF)-alpha to treat cancer. Many of these studies demonstrated dose-limiting systemic side effects from high concentrations of TNF-alpha. The recent focus has been on developing a local delivery system for TNF-alpha to minimize the systemic response. METHODS: This study was part of a phase I open-label multi-institutional trial using TNFerade. We focus on the patients treated at Baylor University Medical Center and provide postoperative and long-term follow-up. TNFerade uses a second-generation nonreplicating adenovirus as the vector for delivery of the human transgene TNF-alpha. An early growth response 1 promoter was placed upstream from the TNF-alpha gene. This promoter is activated by ionizing radiation, thus allowing for temporal and spatial control of TNF-alpha release. Tumors were injected over 5 weeks with ionizing radiation given 3 days after injections for 6 weeks. Tumor response was measured by computed tomographic imaging and physical examination. RESULTS: As described in our original experience, no patients experienced dose-limiting toxicities up to doses of 4 x 10(11) particles per injection. Tumors injected demonstrated a response independently of histology. Four patients had complete regression of the tumor injected. Three patients with complete regression have survived > or = 2 years from the time of treatment. CONCLUSIONS: Both short-term and long-term safety are observed with TNFerade. These data demonstrate the need for phase II trials.

A prospective randomized trial demonstrating valved implantable ports have fewer complications and lower overall cost than nonvalved implantable ports.

BACKGROUND: The purpose of the current study was to evaluate whether a totally implanted valved subcutaneous port system would have fewer complications as compared to a standard nonvalved port. METHODS: Study subjects requiring port placement were randomized to receive a valved port (PASV; Boston Scientific, Natick, MA) or a nonvalved port (BardPort; Bard Accesss Systems, Salt Lake City, UT). Each port was placed with standard operative technique. Difficulty with blood return, excess time spent accessing the port, and required interventions were reported over the initial 180 days of port usage. RESULTS: Seventy-three patients were randomized to receive either a valved port (n = 37) or a nonvalved port (n = 36). No major complications were identified from port placement, and there were no differences in rates of infection between the 2 ports. A reported inability to withdraw blood was noted in the valved port group on 21 of 364 (5.8%) port accessions and in the nonvalved port group on 37 of 341 (11%) accessions (P = 0.02). Significantly more total time was spent ensuring adequate blood draw from nonvalved ports as opposed to valved ports (750 minutes vs. 1545 minutes, respectively) (P <0.03). CONCLUSIONS: This study revealed that the PASV valved port is associated with significantly fewer instances of poor blood return and less nursing access time, indicating that a port with a PASV valve may be superior to a nonvalved device.

Routine ilioinguinal nerve excision in inguinal hernia repairs.

BACKGROUND: Chronic inguinal neuralgia is one of the most significant complications following inguinal hernia repair. Routine ilioinguinal nerve excision has been proposed as a means to avoid this complication. The purpose of this report is to evaluate the long-term outcomes of neuralgia and paresthesia following routine ilioinguinal nerve excision compared to nerve preservation. METHODS: Retrospective chart review identified 90 patients who underwent Lichtenstein inguinal hernia repairs with either routine nerve excision (n = 66) or nerve preservation (n = 24). All patients were contacted and data was collected on incidence and duration of postoperative neuralgia and paresthesia. Comparison was made by chi(2) analysis. RESULTS: The patients with routine neurectomy were similar to the group without neurectomy based on gender (male/female 51/15 vs. 19/5) and mean age (68 +/- 14 vs. 58 +/- 18 years). In the early postoperative period (6 months), the incidence of neuralgia was significantly lower in the neurectomy group versus the nerve preservation group (3% vs. 26%, P <0.001). The incidence of paresthesia in the distribution of the ilioinguinal nerve was not significantly higher in the neurectomy group (18% vs. 4%, P = 0.10). At 1 year postoperatively, the neurectomy patients continued to have a significantly lower incidence of neuralgia (3% vs. 25%, P = 0.003). The incidence of paresthesia was again not significantly higher in the neurectomy group (13% vs. 5%, P = 0.32). In patients with postoperative neuralgia, mean severity scores on a visual analog scale (0-10) were similar in neurectomy and nerve preservation patients at all end points in time (2.0 +/- 0.0 to 2.5 +/- 0.7 vs. 1.0 +/- 0.0 to 2.2 +/- 1.5). In patients with postoperative paresthesia, mean severity scores on a visual analog scale (0-10) were similar in the neurectomy and nerve preservation patients at 1 year (2.5 +/- 2.2 vs. 4.0 +/- 0.0) and 3 years (3.5 +/- 2.9 vs. 4.0 +/- 0.0). CONCLUSIONS: Routine ilioinguinal neurectomy is associated with a significantly lower incidence of postoperative neuralgia compared to routine nerve preservation with similar severity scores in each group. There is a trend towards increased incidence of subjective paresthesia in patients undergoing routine neurectomy at 1 month, but there is no significant increase at any other end point in time. When performing Lichtenstein inguinal hernia repair, routine ilioinguinal neurectomy is a reasonable option.

Neuroendocrine Tumors of the Pancreas.

Neuroendocrine tumors (NETs) are rare tumors of the endocrine pancreas that require a high degree of suspicion for timely diagnosis. Diagnosis is often delayed due to the nonspecific and intermittent presentation of symptoms. As many as 45% to 55% of tumors are nonfunctional and are typically diagnosed secondary to mass effect related symptoms or found incidentally. Functional tumors often are symptom specific and are diagnosed at an earlier stage than nonfunctional tumors. The challenging aspects of treating NETs are localizing the tumors, treating extensive or metastatic disease, and palliating symptoms. Most NETs have an indolent course, and aggressive multimodality treatment is often indicated and encouraged.

Patterns of drainage and recurrence following sentinel lymph node biopsy for cutaneous melanoma of the head and neck.

OBJECTIVES: To analyze lymphatic drainage patterns and recurrence patterns in patients undergoing sentinel lymph node biopsy (SLNB) for cutaneous head and neck melanoma. DESIGN: Retrospective review of a consecutive series with a mean follow-up of 35 months. SETTING: Tertiary cancer care center. PATIENTS: Fifty-one patients with clinically node-negative cutaneous melanoma of the head and neck region staged by means of SLNB. INTERVENTIONS: Sentinel lymph nodes (SLNs) were identified using preoperative lymphatic mapping along with intraoperative gamma probe evaluation and isosulfan blue dye injection. Patients with a positive SLNB finding by hematoxylin-eosin or immunohistochemical evaluation underwent completion lymphadenectomy of the affected lymphatic basin and were considered for further adjuvant treatment. Patients with a negative SLNB finding were observed clinically. MAIN OUTCOME MEASURES: Location characteristics of SLNs, incidence of positive SLNs, same-basin recurrence, and disease-free survival. RESULTS: The mean number of SLNs per patients was 2.75. The extent of SLNB included removal of 1 node (n = 11), multiple nodes from 1 basin (n = 18), 1 node in multiple basins (n = 7), and multiple nodes in multiple basins (n = 15). Drainage to unexpected basins was found in 13 of 51 patients. Parotid region drainage was identified in 18 patients. There were no same-basin recurrences in patients with a negative SLNB finding. Thirty-six-month disease-free survival was 88.9% for patients with a negative SLN and 72.9% for patients with a positive SLN (P=.17). CONCLUSIONS: The number and location of SLNs is variable and difficult to predict for head and neck cutaneous melanoma. Preoperative lymphoscintigraphy is an important planning instrument to guide complete removal of all SLNs. Based on 3-year follow-up, this procedure can be expected to provide low same-basin recurrence rates for patients with a negative SLN.

Laparoscopic Roux-en-Y gastric bypass in morbidly obese and super morbidly obese patients.

BACKGROUND: Our objective was to compare the outcomes after laparoscopic Roux-en-Y gastric bypass (RYGB) in morbidly obese (body mass index [BMI] <50) patients with super morbidly obese (BMI >50) patients. METHODS: A prospective analysis of 120 patients who underwent laparoscopic RYGB at a community based teaching hospital between January 2002 and August 2002 was performed. Sixty patients with BMI <50 were compared with 60 patients with BMI >50. Study endpoints included: operative time, length of stay, and overall complication rates including early (<7 days) and late (>7 days) complications. RESULTS: Mean BMI in the obese group was 44.6 (range 39 to 49) versus 58.6 (range 50 to 100) in the superobese group. Medical comorbidities, age, and sex distribution were similar in both groups. Mean operative time in the obese group was 128 minutes (range 75 to 225) versus 144 minutes (range 75 to 240) in the superobese group. The overall complication rate was 10% in the obese group versus 20% in the superobese group. (P = 0.2) With regard to the obese group, the early complication rate was 5% (n = 3). These included 2 upper gastrointestinal bleeds and 1 respiratory failure. The late complication rate in this group was also 5% (n = 3). These were all anastomotic strictures requiring endoscopic dilation. In comparison, in the superobese group, the early complication rate was 8% (n = 5). These included 2 upper gastrointestinal bleeds, 1 pneumonia, 1 superficial wound infection, and 1 small bowel obstruction. The late complication rate in this group was 12% (n = 7). These included 4 anastomotic strictures, 1 incisional hernia, 1 pulmonary embolism, and 1 anastomotic leak. There were no conversions to open gastric bypass or deaths in either group. Median length of stay in both groups was 2 days. CONCLUSIONS: Our data demonstrate no significant difference in operative times, complication rates or length of stay between morbidly obese and super morbidly obese patients undergoing laparoscopic RYGB. Laparoscopic RYGB is safe and technically feasible in the super morbidly obese patient population.

Patterns of recurrence after sentinel lymph node biopsy for cutaneous melanoma.

BACKGROUND: Previous sentinel lymph node (SLN) studies for cutaneous melanoma have shown that the SLN accurately reflects the nodal status of the corresponding nodal basin. However, there are few long-term studies that describe recurrence site patterns, predictors for recurrence, and overall survival and disease-free survival after SLN biopsy. METHODS: A retrospective review of patients over a 6-year period was performed to determine patient outcomes and the patterns of recurrence. In all cases, Tc-99 sulfur colloid along with isosulfan blue dye was injected at the primary melanoma site. After resection, the SLN was serially sectioned and evaluated by hematoxylin and eosin staining and immunohistochemistry. RESULTS: One hundred ninety-eight patients were identified who underwent SLN biopsy for cutaneous melanoma including T1 (n = 21), T2 (n = 88), T3 (n = 75), and T4 (n = 14) primary tumors. Of these patients, 38 had a positive SLN. Of the 38 patients with a positive SLN (mean follow-up 38 months), recurrent disease was identified in 10 (26.3%) at a mean interval of 14.2 months. The site of first recurrence was distant (n = 4) and local (n = 6). Regional lymphatic basin recurrence was not identified. Of the 160 patients with a negative SLN (mean follow-up 50 months), recurrent disease was identified in 16 (10.0%) at a mean interval of 31.3 months. The site of first recurrence was systemic (n = 11), local (n = 4), and nodal (n = 1). Overall survival and disease-free survival for patients with a positive SLN at 55 months was 53.3% and 47.7% respectively, while overall survival and disease-free survival for patients with a negative SLN at 53 months was 92.2% and 87.7% respectively (P <0.01). Univariate and multivariate analysis of the entire cohort (n = 198) identified primary tumor depth and positive SLN status as significant predictors of recurrence. CONCLUSIONS: The incidence of nodal basin recurrence after SLN biopsy was found to be 0.6%. Primary tumor depth and pathological status of the SLN are significant predictors of local and systemic recurrence. Long-term follow-up indicates that patients with a positive SLN clearly recur sooner and have decreased overall survival than those with a negative SLN.