Unsuccessful Surgical Exploration Research Articles

Anatomic symmetry of anterolateral thigh flap perforators: a computed tomography angiographic study.

The anterolateral thigh flap is a workhorse reconstructive flap. Versatility in design is a key strength but perforator anatomy can be variable. Inability to locate perforators prompts consideration of contralateral thigh exploration. However, such exploration would be futile if the absence of perforators proves symmetrical. This study assesses the symmetry of anterolateral thigh flap vasculature using computed tomography angiography (CTA). A retrospective analysis of 20 bilateral thigh CTAs was performed. Each limb was assessed for number, course, location and size of perforators. Only vessels >0.5 mm in size at origin were included. Location was standardized between patients using perforator distance/thigh length ratio. Results were analysed using Wilcoxon signed-rank test. In each thigh, the average number of perforators was 3.58 and average perforator distance/thigh length ratio was 0.358 ± 0.08. Between both limbs of the same patient, the mean difference in number of perforators was 0.55 (P = 0.002), and difference in average perforator size was 0.3 mm (P < 0.001). Average perforator location differed by a mean of 3% of thigh length (P < 0.001) between thighs. While average vessel size and location appear similar, there does not appear to be symmetry in the number of perforators. Surgical exploration of the contralateral thigh in an absence of perforators should be considered. In patients where abnormal anatomy is expected, mapping with CTA could be considered to reduce morbidity associated with unsuccessful surgical exploration and dissection.

For Insulinomas, No Place to Hide

What a splendid idea to use the receptor for glucagonlike peptide-1 (GLP1), which is widely expressed onhealthys-cells, tovisualize their tumorous counterpart, insulinomas! After the preliminary report of this novel technique in animals (1) and in two patients (2), Christ et al. (3) now report in a series of six consecutive insulinoma patients that they could localize the typically small insulinomas in all cases. Inspired by the finding that GLP-1 receptors are commonly expressed in insulinoma cells, this observation was based on a sound hypothesis. This novel approach certainly extends our armamentarium of imaging techniques (transabdominal ultrasound, endoscopic ultrasound, intraoperative ultrasound, computed tomography scan, magnetic resonance imaging, angiography, somatostatin receptor scintigraphy, selective arterial calcium injection/insulin stimulation, and portal venous sampling), which have traditionally been used with mixed success. This less than optimal success is due to the small size of a typical insulinoma often being below the detection limit of the respective methods. In the absence of a more reliable direct imaging method, the diagnosis of an insulinoma, and thus the recommendation for explorative laparotomy, has often been based solely on the biochemical evidence for an insulin-producing tumor. However, by this traditional approach, patients with other causes of hyperinsulinemia (e.g. factitious hypoglycemia due to sulfonylureas) may also be subjected to surgery, and the intraoperative detection of the tumor solely depends on the experience of the surgical team. Finally, extrapancreatic insulinomas may remain undetected even during an exploratory laparotomy. The evidence for an insulinoma based on this novel imaging approach will certainly facilitate the decision of patients and physicians to undergo and to accept the potential risks of surgery. Despite the results presented by Christ et al. (3) certainly being promising, a couple of questions related to the potential future role for GLP-1 receptor scintigraphy in the diagnostic workup of insulinoma patients remain. How does this method perform in selected patients in whom other methods did not clarify the site of the insulinoma? The standard to be compared against probably should be endoscopic ultrasound, which identifies the greatest percentage of insulinomas [ 90% (4)] compared with other methods. Even more challenging would be a group of patients with firm biochemical proof of hyperinsulinemic hypoglycemia, but an unsuccessful surgical exploration by an experienced surgeon, and especiallywhenintraoperativeultrasoundwasemployed(5). Such patients will most likely benefit from being referred to the authors of the current study or other sites that can offer this method in the future. Anotherquestionof interest iswhether false-positive findings could potentially be observed. This would be particularly deleterious in cases of sulfonylurea-induced factitious hypoglycemia (6), a condition that can be biochemically difficult to discern from an insulinoma. Furthermore, will metastases, which occur in approximately 10% of insulinomas with malignant features (7), be reliably detected, or is it possible that malignant insulinoma cells dedifferentiate and lose GLP-1 receptor expression? The fact that in the present report “difficult to localize” insulinomas were included, especially one residing in an extrapancreatic site, certainly provides a rationale for positive expectations. Technically speaking, a rather large dose of exendin-4 (30 g per injection) was used for GLP-1 receptor scintigraphy in the study of Christ et al. (3) published in this issue of JCEM (3). It was not surprising that this dose was associated with nausea (8). More surprising, however,

Strategy for the Maximal Use of Native Arteriovenous Fistulae for Hemodialysis

The long-term survival and quality of life of patients on hemodialysis is dependent on the adequacy of dialysis via an appropriately placed vascular access. The native arteriovenous fistula (AV fistula) at the wrist is generally accepted as the vascular access of choice in hemodialysis patients due to its low complication and high patency rates. It has been shown beyond doubt that an optimally functioning AV fistula is a good prognostic factor of patient morbidity and mortality in the dialysis phase. Recent clinical practice guidelines recommend the creation of a vascular access (native fistula or synthetic graft) before the start of chronic hemodialysis therapy to prevent the need for complication-prone dialysis catheters. A multidisciplinary approach, including nephrologists, surgeons, interventional radiologists, and nurses should improve the hemodialysis outcome by promoting the use of native AV fistulae. An important additional component of this program is the Doppler ultrasound for preoperative vascular mapping. This approach may be realized without unsuccessful surgical explorations, with a minimal early failure rate, and a high maturation, even in risk groups such as elderly and diabetic patients. Vascular access care is responsible for a significant proportion of health care costs in the first year of hemodialysis. These results also support clinical practice guidelines that recommend the preferential placement of a native fistula.

Impact of pre-operative venography on the planning and outcome of vascular access for hemodialysis patients

Pre-operative venous mapping has increased dramatically in most dialysis units since the Dialysis Outcome Quality Initiative (DOQI) guidelines recommended a native arteriovenous venous fistula (AVF) rather than a graft for hemodialysis (HD) access procedures. However, there are conflicting consequences as a result of this policy. Some studies have showed that routine mapping has resulted in a marked increase in maturation rate while others have observed the reverse. This study aimed to evaluate the impact of pre-operative venography on the planning and outcome of AVF for our HD patients. A prospective study was performed on all patients with end-stage renal disease (ESRD) who had HD access procedures and pre-operative venography between October 2003 and November 2005. Upper limb venography was done for all patients except those that required primary access and had visible veins. All patients had HD immediately after the venography. Access procedure selection was based on the result of the venography. The complications of venography, the surgical procedure and the outcome were recorded. One hundred and twenty-nine patients with ESRD who had pre-operative venography were included in this study. They were mostly middle age (mean age +/- SD = 41 +/- 15.5 yrs) with a high rate of diabetes mellitus (53%). No single complication was reported. A graft was placed in six patients (5%) only. Unsuccessful surgical exploration was 0%. Early failure was in 10 patients (8%). Pre-operative venography resulted in an increase in the number of AVFs. It can improve the results of HD access procedures by selecting the most suitable veins.

Strategy for the Maximal Use of Native Arteriovenous Fistulae for Hemodialysis

The long-term survival and quality of life of patients on hemodialysis is dependant on the adequacy of dialysis via an appropriately placed vascular access. The native arteriovenous fistula (AV fistula) at the wrist is generally accepted as the vascular access of choice in hemodialysis patients due to its low complication and high patency rates. It has been shown beyond doubt that an optimally functioning AV fistula is a good prognostic factor of patient morbidity and mortality in the dialysis phase. Recent clinical practice guidelines recommend the creation of a vascular access (native fistula or synthetic graft) before the start of chronic hemodialysis therapy to prevent the need for complication-prone dialysis catheters. A multidisciplinary approach, including nephrologists, surgeons, interventional radiologists, and nurses should improve the hemodialysis outcome by promoting the use of native AV fistulae. An important additional component of this program is the Doppler ultrasound for preoperative vascular mapping. This approach may be realized without unsuccessful surgical explorations, with a minimal early failure rate, and a high maturation, even in risk groups such as elderly and diabetic patients. Vascular access care is responsible for a significant proportion of health care costs in the first year of hemodialysis. These results also support clinical practice guidelines that recommend the preferential placement of a native fistula.

Surgical treatment of insulinoma.

The role of preoperative and intraoperative procedures for the localization of insulinoma has been extensively debated. Transhepatic portal vein sampling before surgery has been recommended when other tests fail to localize the tumour. To determine the role of different investigations, 53 patients with insulinoma, four with hyperplasia or nesidioblastosis and one with insulin autoimmune syndrome were studied. Patients were operated on in three consecutive periods during each of which a different localization procedure was considered to represent the 'gold standard'. During the first period, of 16 patients (including one with hyperplasia) investigated by arteriography, 13 underwent successful resection. Tumours in the other three patients with insulinoma were resected at a second operation, one during the first period and one each during the second and third periods. During the second period, 28 patients underwent exploration after transhepatic portal sampling: the tumour was found in all 26 patients with insulinoma operated on in this hospital, one patient with hyperplasia is receiving medical treatment and one patient had unsuccessful surgical exploration elsewhere despite positive findings on arteriography and transhepatic portal sampling performed in this department. During the third period 13 procedures were performed. All were successful using intraoperative ultrasonography without transhepatic portal sampling. In three further patients intraoperative localization failed because of non-adenomatous beta cell disease. Left-sided resection successfully cured symptoms in two patients with hyperplasia and prompted the diagnosis of insulin autoimmune syndrome. High success rates for surgical treatment of insulinoma can be achieved with transhepatic portal vein sampling or intraoperative ultrasonography. Transhepatic portal sampling is therefore unnecessary before a first operation on the pancreas for insulinoma. In the rare failures of intraoperative localization of an insulinoma, a small left pancreatic resection can help to distinguish insulinoma from hyperplasia without precluding further segmental resection.

Vascular Access for Hemodialysis: Arteriovenous Fistula

The long-term survival and quality of life of patients on hemodialysis (HD) is dependant on the adequacy of dialysis via an appropriately placed vascular access. The optimal vascular access is unquestionably the autologous arteriovenous fistula (AVF), with the most common method being the conventional radio-cephalic fistula at the wrist. Recent clinical practice guidelines recommend the creation of native fistula or synthetic graft before the start of chronic HD therapy to prevent the need for complication-prone dialysis catheters. This could also have a beneficial effect on the rapidity of worsening kidney failure. A multidisciplinary approach (nephrologists, surgeons, radiologists and nurses) should improve the HD outcome by promoting the use of AVF. An important additional component of this program is the Doppler ultrasound for preoperative vascular mapping. Such an approach may be realized without unsuccessful surgical explorations, with a minimal early failure rate and a high maturation, even in patients with diabetes mellitus.

US vascular mapping before hemodialysis access placement.

To prospectively assess the effect of preoperative ultrasonographic (US) mapping on surgical selection, placement of arteriovenous fistulas (AVFs) and grafts, and negative surgical exploration rates. US assessment of the upper extremity arterial and venous anatomy was performed in 70 patients with chronic renal failure before surgical evaluation. The surgeon documented the planned access procedure, which was based on physical examination results, and then reviewed the US preoperative mapping report. The surgical procedure and outcome were recorded. Fifty-two of the 70 patients who underwent mapping had vascular access placement. Preoperative US mapping resulted in a change in the planned surgical procedure in 16 (31%) of the 52 patients. An AVF rather than the planned graft was placed in eight (15%) patients. The AVF placement rate increased from 32% (126 of 395 patients) to 58% (30 of 52 patients). Unsuccessful surgical explorations decreased from 11% (28 of 256) to 0%. Preoperative US mapping before hemodialysis access placement can result in a change in surgical management, with an increased number of AVFs placed and an improved likelihood of selecting the most functional vessels preoperatively. Further study is needed to determine longer term outcomes.

Localization of Abnormal Parathyroid Tissue With Use of Technetium-99m-Sestamibi

To evaluate the efficacy of "double-phase" technetium-99m-sestamibi scanning in the localization of abnormal parathyroid tissue in patients with hyperparathyroidism. We present a prospective review of patients with hyperparathyroidism seen at a university teaching hospital between June 1994 and May 1997. Twenty-four patients entered into the study underwent preoperative localization with double-phase technetium-99m-sestamibi. The nuclear medicine results were compared with the operative findings. The Tc-99m-sestamibi scan correctly identified the location of single parathyroid adenomas in 22 patients (100%). Of the other two patients, both with diffuse parathyroid hyperplasia, one had a negative sestamibi scan and one had only the two inferior parathyroid glands localized on the sestamibi scan. One patient with recurrent hypercalcemia, who previously underwent total parathyroidectomy and parathyroid autotransplantation into the left forearm, had activity localized to that forearm but not to the neck. Subsequently, hyperplastic parathyroid tissue was successfully removed from the transplantation site. Another patient, who had previously undergone two unsuccessful surgical explorations prompted by hyperparathyroidism, had sestamibi localization of an adenoma inferior and medial to the right submandibular gland. The third surgical exploration disclosed a large adenoma medial to the carotid artery, just below the angle of the jaw. In two elderly, debilitated women with positive scans, adenomas were removed with use of local anesthesia. Of 22 patients in whom long-term follow-up was available, 21 remained normocalcemic for a mean period of 11.4 +/- 1.7 months postoperatively. One patient in whom hyperplastic parathyroid tissue had been removed from the left forearm had recurrence of hypercalcemia 1 year after operation. Technetium-99m-sestamibi scanning is a reliable method for identifying parathyroid adenomas but not as helpful in localizing hyperplastic parathyroid glands. The precise localization of an adenoma simplifies surgical exploration and in selected patients may allow excision of the adenoma under local anesthesia. Tc-99msestamibi scanning has become the preferred method for noninvasive localization of abnormal parathyroid glands.

Diagnosis and microsurgical approach to far-lateral disc herniation in the lumbar spine

Lumbar-disc herniations that occur beneath or far lateral to the intervertebral facet joint are increasingly recognized as a cause of spinal nerve root compression syndromes at the upper lumbar levels. Failure to diagnose and precisely localize these herniations can lead to unsuccessful surgical exploration or exploration of the incorrect interspace. If these herniations are diagnosed, they often cannot be adequately exposed through the typical midline hemilaminectomy approach. Many authors have advocated a partial or complete unilateral facetectomy to expose these herniations, which can lead to vertebral instability or contribute to continued postoperative back pain. The authors present a series of 25 patients who were diagnosed as having far lateral lumbar disc herniations and underwent paramedian microsurgical lumbar-disc excision. Twelve of these were at the L4-5 level, six at the L5-S1 level, and seven at the L3-4 level. In these cases, myelography is uniformly normal and high-quality magnetic resonance images may not be helpful. High-resolution computerized tomography (CT) appears to be the best study, but even this may be negative unless enhanced by performing CT-discography. Discography with enhanced CT is ideally suited to precisely diagnose and localize these far-lateral herniations. The paramedian muscle splitting microsurgical approach was found to be the most direct and favorable anatomical route to herniations lateral to the neural foramen. With this approach, there is no facet destruction and postoperative pain is minimal. Patients were typically discharged on the 3rd or 4th postoperative day. The clinical and radiographic characteristics of far-lateral lumbar-disc herniations are reviewed and the paramedian microsurgical approach is discussed.

Laparoscopy as an aid in the diagnosis and management of the impalpable testis

Fourteen children with impalpable testes, 10 bilateral and 4 unilateral, were examined laparoscopically. Eleven testes and two primitive undifferentiated gonads were seen in the abdomen. Exploration of the inguinal canals into which the vasa and testicular vessels were seen passing from the abdomen revealed a further two testes but nine were absent. One testis had atrophied as a result of previous torsion. Inappropriate internal genitalia were seen in two boys with hypospadias. One boy in whom both testes were seen in the abdomen had undergone a previous unsuccessful surgical exploration. None of the children developed any complications from the laparoscopy and the examination failed to reveal only one abdominal testis.

Selective spermatic arteriography for localization of an impalpable undescended testis.

Thirty patients with undescended testes, including 15 children, were studied by selective spermatic angiography. Six patients had both arteriography and venography, and 24 had bilateral arteriography for assessment of testicular size. In 7 patients, arteriography revealed an impalpable testis following unsuccessful surgical exploration. In 17, subsequent surgery confirmed the angiographic findings; testicular agenesis was diagnosed in 7, and catheterization failed in 2. There were no complications. Preoperative testicular arteriography localizes the testis, facilitates surgery, and may aid in tumor detection. Angiographic identification of testicular agenesis precludes exploration. Arteriography is more accurate, simpler, and less complicated than venography.