Surgery

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2010-02-01

Contribution of biologically derived nanoparticles to disease

Maria K. Schwartz, John C. Lieske, Virginia M. Miller — 2009-09-23

Dr Charles H. Mayo stated in 1922, “It is unfortunate that so few appreciate from what small causes diseases come.” Today, with advances in technology, the burgeoning field of nanotechnology brings new meaning to Dr Mayo's words. Manufactured and natural materials of nanometer scale () provide the medical community with new products for diagnostics, drug delivery, and biomaterials for restorative and reconstructive surgery. A key requirement for these new products is that the nanoparticle (NP) itself does not initiate detrimental or pathogenic processes in healthy tissue. This prerequisite is an important consideration in the field of nanotechnology, because nanomaterials can have unique effects on biologic systems, depending on many factors such as the materials' original composition and size. Indeed, materials on a nanolevel often have different characteristics and effects than the same materials at a macrolevel.

Prevalence and clinical relevance of pathological hepatic changes occurring after neoadjuvant chemotherapy for colorectal liver metastases

2010-02-01

Background: Hepatotoxicity from neoadjuvant chemotherapy before liver resection for colorectal metastases (CRLM) has been recently reported. The purpose of the present study was to evaluate the prevalence and the clinical relevance of this phenomenon. It was a retrospective study conducted at an academic secondary referral hospital.Methods: One hundred patients suffering from CRLM and having undergone the resection of at least 1 liver segment (114 hepatectomies; 100 first, 13 second, 1 third) were enrolled. The surgical specimens were reviewed using standardized criteria for diagnosis and grading of pathological liver changes. Their impact on perioperative bleeding, transfusion, morbidity, and mortality rates after liver resection was studied.Results: Sinusoidal congestion was the single hepatotoxic lesion significantly more frequently encountered in patients having received neoadjuvant chemotherapy (P = .0014), even in patients having received chemotherapy more than 6 months before liver resection, but was not related to the type of chemotherapy. Despite a significant increase in perioperative blood losses, the presence of sinusoidal lesions, even severe, had no clinically significant effect on postoperative mortality, morbidity, and transfusion rates.Conclusion: Neoadjuvant chemotherapy before operation for CRLM is significantly associated to sinusoidal congestion, irrespective of the type of chemotherapy but without any significant impact on postoperative clinical outcome. Sinusoidal lesions may persist more than 6 months after the end of chemotherapy.

Chemotherapy liver injury

Christopher D. Anderson, Ravi S. Chari — 2010-02-01

Advances in chemotherapy and the increased use of pre-operative chemotherapy have combined to bring a welcome improvement in the outcome of liver metastatic colorectal carcinoma. However, accompanying this has been a greater awareness of chemotherapy-associated hepatotoxicity. Thus, a clinical paradox has emerged wherein patients who present with initially unresectable liver metastatic colorectal carcinoma may be “downsized” to resectability, but the chemotherapy regimens may, in turn, increase the potential risks of or even preclude major liver resection. Many reports associate this chemotherapy-induced hepatotoxicity to increased operative morbidity and mortality. In this issue, Hubert et al attempt to address the clinical relevance of this problem by reviewing a large cohort of patients who underwent hepatic resection for liver metastatic colorectal carcinoma. Their results are corroborated by prior studies by suggesting that preresection chemotherapy, especially within the preceding 6 months, is associated sinusoidal injury of the liver. However, they fail to demonstrate an increase in operative morbidity or mortality related to preresection chemotherapy. It should be pointed out that this group employed an aggressive pre-operative planning protocol designed to optimize the remnant liver volume in chemotherapy-exposed patients.

Prognostic impact of the width of subserosal invasion in gastric cancer invading the subserosal layer

2009-09-16

Background: The depth of wall invasion is one of the most important prognostic factors in patients with gastric cancers. We hypothesized that the horizontal width of spread of the neoplasm in the subserosal layer correlated with frequency of latent tumor exposure to the subserosal surface in subserosal (ss) gastric cancer.Methods: We compared retrospectively the relationship between the horizontal width of ss invasion and other clinicopathologic factors in 124 patients with ss cancer confirmed carefully to have T2 and not T3 neoplasms. Selected clinicopathologic parameters of these ss patients were compared to 134 patients with serosal penetration (se) by gastric cancer, and 78 patients with invasion of the muscularis propria only (mp).Results: The width of ss invasion was found to be an important prognostic factor on both univariate (P < .001) and multivariate analyses (P = .006). The prognosis of ss-cancer with narrow-width invasion (less than 20 mm) was similar to that of mp-cancer, while the prognosis of ss-cancer with wide width (more than 20 mm) was similar to that of se-cancer.Conclusion: Our findings showed that narrow-width ss-cancer (<20 mm) behaved very similar to mp-cancers, while wide ss-cancers (≥20 mm) behaved very similar to se-cancers. These findings demonstrated the prognostic impact of the width of cancer invasion in subserosal layer in patients with ss-cancer. Intensive chemotherapy and close follow-up should be recommended for ss-cancer patients with greater than 20 mm involvement of the subserosal layer.

Impact of lymphovascular invasion in patients with stage I gastric cancer

2009-11-02

Background: Patients with stage I gastric cancer often suffer from tumor recurrence despite a generally favorable operative outcome. It is therefore important to determine the prognostic factors in order to improve such outcomes.Methods: Between April 1985 and March 2000, a total of 1,880 patients with histologically proven stage I gastric cancer were included in this study. Operative outcomes (survival time, prognostic factors, pattern of recurrence) were evaluated in these patients.Results: Multivariate analysis in patients with all stage I gastric cancer revealed that depth of invasion, lymph node metastasis, and lymphovascular invasion independently influenced prognosis. Moreover, advanced age was selected as an independent prognostic factor in patients with stage IA, and lymphovascular invasion in patients with stage IB gastric cancer by multivariate analyses. The 5-year survival rates in stage T1N1 patients with moderate to severe lymphovascular invasion, T2N0 with moderate to severe lymphovascular invasion, and II were 95.1%, 83.5%, and 76.9%, respectively. There was a significant difference in survival time between stage T1N1 and II (P = .0189) but not between stage T1N1 and T2N0 or stage T2N0 and II.Conclusion: T2N0 gastric cancer patients with moderate to severe lymphovascular invasion may be suitable candidates for adjuvant chemotherapy.

Repair using the pectoralis major muscle flap for anastomotic leakage after esophageal reconstruction via the subcutaneous route

2009-11-02

Background: Anastomotic leakage with an intractable cutaneous fistula frequently develops after an esophagectomy and reconstruction via the subcutaneous route.Methods: A pectoralis major muscle (PMM) flap was used for the treatment of 6 patients with esophageal cancer who developed anastomotic leakage with fistula after reconstruction via the subcutaneous route. A gastric tube and colon had been used for reconstruction in 2 and 4 patients, respectively. A trimming and repair of the leakage site was initially performed and the anastomotic site was then covered with a muscle flap.Results: Recurrent anastomotic leakage did not develop in 5 patients. Among these patients, oral intake was initiated from 11–15 days after the repair operation in 4 patients. A patient having recurrent anastomotic leakage after a repair operation recovered well with conservative therapy.Conclusion: The coverage with a PMM flap over the repair site is a simple method for preventing the development of recurrent leakage after a repair operation. Even when recurrent anastomotic leakage has occurred after this operation, healing is normally expected by means of conservative treatment. We, therefore, recommend this method for the repair of intractable anastomotic leakage after reconstruction via the subcutaneous route for esophageal cancer.

Fast-track surgery after laparoscopic colorectal surgery: Is it feasible in a general surgery unit?

2009-11-06

Background: The aim of the “fast-track surgery” program is to decrease the peri-operative stress response to surgical trauma and thus to a decrease in complication rates after elective surgery. Critics of fast-track (FT) rehabilitation may argue that all reports of successful programs came from major specialized hospital units and that implementation in smaller or less specialized units may be difficult if not impossible.Methods: We retrospectively studied 101 patients who, from November 2004 to October 2007, underwent laparoscopic colorectal surgery in our institute. A detailed FT surgery protocol had been prepared and given to patients, physicians and nurses, with the aim to create a standard treatment. Data about demographics, ASA score, pre-operative complicating diseases, diagnosis, type of surgery, and postoperative clinical data were analyzed. Univariate analysis of the relationship between all factors (patient characteristics, intervention characteristics, protocol compliance and presence of complications) described here and length of hospital stay was performed.Results: We compared our results to published major trials and observed no substantial differences in morbidity, mortality and length of postoperative hospital stay between the 2. Univariate analysis showed that compliance to the elements of the FT protocol influences the length of postoperative period more significantly than patient characteristics or surgical procedure.Conclusion: Based on 6 comparative single-center studies, the FT program was found to reduce length of hospital stay, and was deemed safe for major abdominal surgeries. Present study shows that enhanced recovery or FT program can also be implemented safely in a general surgery unit.

Significant parameters for surgery in adult intussusception

2009-11-02

Intussusception is defined as the telescoping of a proximal segment of bowel into the lumen of the adjacent distal segment. It was first reported in 1674 by Barbette of Amsterdam and remains a relatively rare entity in the adult population. Only 5% of all intussusceptions are found in adults and they comprise 1–5% of all cases of intestinal obstructions. The exact mechanism precipitating an intussusception is still unknown. It is believed that any lesion in the bowel wall or irritant within the bowel lumen may alter the normal peristalsis pattern and cause an invagination leading to intussusception. The diagnosis is difficult as the symptoms may be nonspecific. Therefore, radiographic imaging, particularly computed tomography (CT) and magnetic resonance imaging (MRI), have been the mainstay of diagnosis.

The value of various definitions of intrathoracic goiter for predicting intra-operative and postoperative complications

2010-02-01

Background: Intrathoracic goiter (IG) is a pathologic and clinical entity defined by criteria that varies from one series to the next. The objective of this study was to determine the most useful definition of IG for predicting intra-operative and postoperative complications.Methods: The study included 201 patients treated for multinodular goiter who met the following criteria: (1) they had no previous thyroid surgery; (2) they had undergone total thyroidectomy; and (3) they were diagnosed with IG according to 1 of the following definitions: (1) clinical; (2) Hsu's; (3) Kocher's; (4) Torre's; (5) Eschapase's; (6) Lahey's; (7) Lindskog's; (8) Crile's; (9) Katlic's; and (10) subcarinal. Three variables were evaluated: (1) intra-operative complications; (2) need for a sternotomy; and (3) postoperative complications.Results: During orotracheal intubation, there were difficulties in 25 cases, all of which were detected using the 6 least restrictive definitions of IG (these range from the clinical definition to Lahey's definition. In 6 (3%) cases, it was necessary to carry out a sternotomy. The thoracic approach could be predicted using Katlic's definition. None of the definitions of IG was useful for predicting postoperative complications.Conclusion: Most definitions of IG can be ignored because they are not clinically relevant. The 6 least restrictive definitions overlap in their utility to predict intubation difficult during the anesthetic process; consequently, the clinical definition should be used because it is the simplest to calculate. Katlic's definition is the most useful for predicting a possible sternotomy for extirpating goiter.

Substernal goiter: What is in a definition?

Ashok R. Shaha — 2010-02-01

Rios et al published an interesting article on the variety of definitions of substernal (intrathoracic) goiters. The authors also reviewed their own experience with 201 patients over a period of 21 years, and attempted to review their complications pertaining to various definitions of substernal goiter. The definition of substernal goiter depends on the individual surgeon and the clinical and radiologic evaluation. In their article, Rios et al describe 10 different definitions of substernal goiter. This lack of a definitive definition is, in part, why the published incidence of substernal goiter varies from 5% to 20%.

Occult lymph node metastases in neck level V in papillary thyroid carcinoma

Young Chang Lim, Eun Chang Choi, Yeo-Hoon Yoon, Bon Seok Koo — 2009-11-12

Background: The extent of lateral neck dissection for clinically evident nodal metastases in the lateral neck in a patient with papillary thyroid cancer (PTC) continues to remain controversial.Methods: We reviewed retrospectively the medical records between March 2005 and March 2008 of 70 patients with PTC who underwent therapeutic lateral neck dissections (level II–V) to establish indications for omission of a level V lymphadenectomy. No patient in the study had a clinically positive level V lymph node. Neck dissection specimens were obtained for histologic analysis for node metastasis with respect to the individual neck levels.Results: Thirty-four (49%), 52 (74%), and 48 (69%) patients had histologically positive lymph nodes in levels II, III, and IV, respectively. Occult metastases in level V were observed in 11 (16%) patients. Isolated positive level V lymph nodes were never found, while all patients with positive level V lymph nodes had simultaneous positive level IV lymph nodes. In addition, there was no instance of a pathologically positive lymph node in level V without a suspicious metastatic lymph node in level IV by preoperative ultrasonography. In multivariate analysis, simultaneous multilevel involvement (level II, III, and IV) of lymphatic metastases was associated with level V metastasis.Conclusion: Level V lymphadenectomy may be omitted in the treatment of PTC patients if positive nodes are not found on histologic exam (frozen section analysis) or by ultrasonography in level IV.

Impact of sleep deprivation on medium-term psychomotor and cognitive performance of surgeons: Prospective cross-over study with a virtual surgery simulator and psychometric tests

2010-02-01

Background: Despite recent work hour restrictions, 24-hour calls remain an important part of patient care. The aim of this study was to assess the impact of 24-hour night calls on the psychomotor and cognitive skills of surgeons with a virtual surgery simulator (VSS) and psychometric tests. We hypothesized that sleep loss impairs surgical skills and concentration performance.Methods: Seventeen surgery residents (test group) and 13 medical students (reference group) performed a 5-day training program on the VSS. The test group was then assessed during a night call on 4 test points (8 am and 4 pm on the on-call day, 8 am on the postcall day, and 8 am on the recovery day) to assess the effects of sleep loss on these surgery residents. The reference group performed the same tests but without a night call.Results: The training resulted in a homogenous performance level for both groups. The average time for the test group was 26 minutes. The analysis between rested and sleep-deprived participants (6.5 ± 0.9 vs 2.9 ± 1.4 hours of night sleep) in the on-call part showed no performance differences. No impairment was found for the VSS and the cognitive tests within the test group between the start of the working day and the start of the postcall day after the night of relative sleep loss. The subgroup analysis showed no significant differences regarding the amount of night sleep and laparoscopic experience.Conclusion: No performance impairment was found for surgeons with a VSS and standardized cognitive tests after a night of relative sleep loss. Although there is no doubt that sleep deprivation ultimately impairs human functioning, typical surgical skills do not necessarily deteriorate with a limited amount of sleep loss under clinical conditions.

The performance effects of sleep deprivation and fatigue

Colin Sugden, Ara Darzi — 2010-02-01

In this issue of Surgery, Lehmann et al present the results of a prospective study examining the effects of sleep deprivation on cognitive and psychomotor performance. The unpredictable nature of acute illness and our commitment to provide around-the-clock in-patient care have contributed to a culture in which medical professionals are required to care for patients both after extended periods of continuous wakefulness and during circadian troughs. Historically, the attitude of professional bodies and employers to this situation has been very much laissez faire. Furthermore, within the surgical profession, coping with arduous working hours as a resident has been viewed as a rite of passage. That the current climate is very different is the result of high-profile cases (such as that of Libby Zion in 1984) and mounting evidence linking sleep deprivation to human performance impairment. In North America and the United Kingdom, the profession is engaged in a debate with government and regulatory authorities regarding the introduction of work-hours restrictions aimed at tackling fatigue-related performance impairment. Many important concerns have been voiced, such as the threat to continuity of care, the significant cost implications, and the reduced availability of training opportunities for residents. At the heart of this debate is simply a lack of confidence in the quality of data that link sleep deprivation with clinical performance impairment. Sleep research is challenging to perform, particularly in the field of medicine in which prospective participants are typically chronically sleep-deprived doctors with little free time. Unfortunately, the publication of poor-quality work has led to a pool of data regarded by many as inconsistent and confusing.

Sleep deprivation and surgical performance: A difficult simulation

Gary L. Dunnington — 2010-02-01

It has now been 6 years since the Accreditation Council for Graduate Medical Education implemented the 80-hour workweek restrictions for residents. The academic surgical community remains divided into two camps regarding these reforms. Some still write longingly for “the way we were” where 100+-hour workweeks selected the fittest to survive a surgical career. The others see work-hours restriction as a long overdue reform and one that has had significant positive impact on the surgical profession and its training programs. The first camp may well look to this issue of Surgery, where Lehmann et al present the results of a prospective study examining the effects of sleep deprivation on cognitive and psychomotor performance as support of the ability of trainees and surgeons in practice to maintain surgical performance in the face of fatigue. Unfortunately, this report will not support that conclusion. Even as the authors suggest, this simulated environment is subject to the Hawthorne effect and demonstrates an ability to maintain performance in one area during a moderate 20- to 30-min time period in a competitive setting. As they point out, “the simulator tests are not standardized nor are reference data available.” The most significant difficulty in this study is the inability of even validated simulators to simulate the collection of knowledge, skills, and attitudes that represent the performance of a surgeon in a clinical setting. We diminish our standing in the public square when we use such studies to suggest that surgeons are somehow able to resist the effects of normal circadian rhythms common to all other humans.

Decreased collagen and increased matrix metalloproteinase-13 in experimental abdominal aortic aneurysms in males compared with females

2009-09-23

Background: This study examined differences in sex in collagen regulation during rodent experimental abdominal aortic aneurysm formation.Methods: Infrarenal aortas of male and female rats were perfused with elastase or saline (control). Aortic diameters were measured at baseline (day 0) and on postoperative days 7 and 14. Transforming growth factor-beta 1, collagen subtypes I and III, and matrix metalloproteinase-13 (MMP-13; collagenase-3) expression and/or protein levels from aortic tissue were determined by real-time reverse transcription polymerase chain reaction and Western blotting. Aortic tissue was stained for total collagen, neutrophils, and macrophages using immunohistochemistry on days 4 and 7.Results: At 7 and 14 days after perfusion, aortic diameter increased in elastase-perfused males compared with females (P < .001 for each). At 4 and 7 days postperfusion, significantly more neutrophils and macrophages were present in elastase-perfused males compared with females. By 7 days postperfusion, protein levels of transforming growth factor-beta 1 were less in males compared with females (P = .04). Type I collagen levels also decreased on days 7 (P < .001) and 14 (P = .002), and type III collagen levels decreased on days 7 (P < .001) and 14 (P < .001) in males compared with females. With Masson's trichrome stain, less adventitial collagen was observed in the elastase-perfused males compared with females. MMP-13 expression (P < .001) and protein levels (P = .006) in elastase-perfused males were greater than females on day 14.Conclusion: This study documents a decrease in types I and III collagen with a concurrent increase in MMP-13 after elastase perfusion in males compared with females. These data suggest that alterations in extracellular matrix collagen turnover may be responsible for altered abdominal aortic aneurysm formation between sexes.

Common femoral artery endarterectomy for occlusive disease: An 8-year single-center prospective study

Enzo Ballotta, Mario Gruppo, Franco Mazzalai, Giuseppe Da Giau — 2009-10-14

Background: Only a few operative or interventional studies have addressed the issue of isolated arterial occlusive disease at the femoral bifurcation, the early and late results reportedly being favorable in the former, controversial in the latter. The purpose of this study was to analyze the peri-operative (30-day) and long-term outcomes of isolated surgical endarterectomy in patients with occlusive disease at the common femoral artery (CFA), providing a baseline for comparison with emerging endovascular procedures.Methods: Over an 8-year period, all consecutive patients referred to our institution for claudication, rest pain, nonhealing ulcer(s), or minor tissue loss, with imaging findings of CFA occlusive disease (isolated or with additional infrainguinal lesions in the ipsilateral limb) amenable to endarterectomy of the CFA (isolated or combined with a profundoplasty or with the endarterectomy of the superficial or deep femoral artery first tract, not >1 cm long) were enrolled in the study. We excluded all patients with major tissue loss for which a contemporary infrainguinal revascularization was performed because treating the inflow disease alone would not be sufficient to heal the ischemic wound(s) owing to the presence of concomitant femoral and/or distal lesions, inadequate collateralization, or poor runoff. Descriptive demographic data, risk factors, clinical manifestations, and operative details were recorded. Primary patency (PP), assisted PP (APP), and limb salvage (LS) rates, freedom from additional proximal or distal revascularization in the ipsilateral limb, and survival were assessed using Kaplan–Meier life tables. Univariate and multivariate analyses were performed to identify which factors could influence CFA segment patency or other parameters.Results: In all, 117 patients were enrolled and underwent 121 CFA endarterectomies, 60.3% for claudication and 39.7% for critical limb ischemia (CLI); 30 patients were excluded because they underwent a contemporary infrainguinal revascularization. All procedures were performed with patients under regional anesthesia and took an average operating time of 1.3 ± 0.7 hours. There were no perioperative deaths or major complications, but 8 (6.6%) local complications. A complete follow-up (mean 4.2 years) was obtained in 111 patients (115 limbs). The 7-year PP, APP, and LS rates were 96%, 100%, and 100%, respectively; the 7-year rates of freedom from further revascularization and survival were 79% and 80%, respectively.Conclusion: Operative endarterectomy in patients with claudication or CLI for occlusive CFA disease proved safe, effective, and durable, and should provide a baseline for comparison with endovascular treatment. Proponents of endovascular procedures as a routine alternative treatment option should bear this in mind.

Tailored neurectomy for treatment of postherniorrhaphy inguinal neuralgia

Maarten J. Loos, Marc R. Scheltinga, Rudi M. Roumen — 2009-10-14

Background: Groin hernia repair occasionally leads to severe chronic pain associated with entrapped or damaged nerves. Conservative treatment is often unsuccessful. Selective neurectomy may be effective, but long-term results are scarce. The authors assessed the long-term efficacy of surgical neurectomy for chronic, postherniorrhaphy groin neuralgia.Methods: A registry of patients with postherniorrhaphy groin pain treated by neurectomy was analyzed. Patients received a questionnaire evaluating the current pain intensity, overall treatment results, and effects on sexual intercourse-related pain. The risk factors for failure and presence of a learning curve were investigated.Results: Fifty-four patients underwent a neurectomy over a 5-year time period, 49 of whom responded to the questionnaire (response rate, 91%). After a median follow-up period of 1.5 years, 52% claimed to be pain free or almost pain free (good to excellent), 24% reported some relief but still felt pain at a regular basis (moderate), and 24% did not benefit (poor or worse). Sexual intercourse-related pain responded favorably to neurectomy in two thirds of patients. There seemed to be a steep learning curve, and poor treatment results depended on previously received pain regimens (P = .021).Conclusion: A selective operative neurectomy for postherniorrhaphy groin neuralgia provides good long-term pain relief in most patients. Hernia surgeons should feel responsible for this iatrogenic complication and should consider incorporating selective neurectomy in their surgical armamentarium.

Roux-en-Y gastric bypass reverses renal glomerular but not tubular abnormalities in excessively obese diabetics

2009-12-11

Background: Obesity and type 2 diabetes are associated with renal dysfunction, which improves after Roux-en-Y gastric bypass (RYGB). During a 12-month follow-up period, we studied prospectively the changes in glomerular and tubular functions that occurred in excessively obese diabetic and non diabetic subjects after RYGB.Methods: The cohort included 35 patients, 54% of whom had type 2 diabetes. Glomerular filtration rate (GFR) was estimated using creatinine clearance. Tubular function was studied by measuring the ratio of urinary cystatin C to urinary creatinine (UCC ratio).Results: Baseline renal parameters, anthropometric characteristics, and changes in body mass index after the surgical procedures were similar between the 2 cohorts. At 12 months after RYGB, creatinine clearance decreased 15% in diabetics (P = .02) and 21% in nondiabetics (P = .03). A change in GFR was seen earlier in the nondiabetics (–29% after 6 months; P = .003). The UCC ratio was increased at both 6- and 12-month follow-ups (P = .03 and .003, respectively) only in the diabetic group.Conclusion: GFR was improved at 12 months after RYGB, with nondiabetics showing a greater propensity score. Tubular function remained unchanged in the nondiabetic subjects, but worsening occurred in the diabetic subjects. These results underscore the importance of reversal of excessive obesity before the onset of frank diabetes.

Antiangiogenic response after 70% hepatectomy and its relationship with hepatic regeneration and angiogenesis in rats

2009-12-11

Background: The aim of this study was to evaluate the antiangiogenic response and its relation to regeneration and angiogenesis after 70% hepatectomy in a rat model.Methods: Sixty-four Wistar albino rats were included in the study. Animals were allocated into 8 groups (n = 8). After a 70% hepatectomy, liver regeneration, angiogenesis, and antiangiogenic response were evaluated in the remnant liver on days 0, 1, 2, 3, 5, 7, 10, and 14. Regeneration and angiogenesis were determined with immunoreactivity to proliferating cell nuclear antigen and vascular endothelial growth factor. Antiangiogenic response was evaluated by detecting collagen 18 m RNA with reverse transcriptase polymerase chain reaction.Results: We showed that liver regeneration peaked at day 1, whereas angiogenesis in the periportal and perisinusoidal areas reached their peak values on days 3 and 7, respectively. Both regeneration and angiogenic activity around perisinusoidal hepatocytes returned to basal activity on the day 10. Antiangiogenic response first appeared on day 5, reached a peak on day 10, and returned to basal values on day 14.Conclusion: Collagen18 mRNA expression is present in the normal liver during the regenerative process. We suggest that the stimulus that causes the cessation of regeneration process may come from hepatocytes, and collagen 18 produced by hepatocytes may modulate this event by inhibiting the angiogenesis.

Matrix metalloproteinase-9 delays wound healing in a murine wound model

2009-12-11

Background: Metalloproteinase-9 (MMP-9) is a type IV collagenase found at elevated levels in chronic wounds. As wounds heal, MMP-9 diminishes. In this study, we investigated whether MMP-9 directly contributes to chronic wound pathogenesis.Methods: Recombinant proMMP-9 was prepared using immortalized keratinocytes transduced by a lentivirus. ProMMP-9 was purified from cell culture media and activated using 4-aminophenylmercuric acetate. Active MMP-9 was then suspended in xanthan gum to a concentration paralleling that found in human chronic wounds. Two parallel 6-mm punch biopsies were made on the backs of C57BL mice. Wounds were treated daily with MMP-9 or vehicle. Wound areas were measured and tissues examined by densitometry, real-time RT-PCR, histology, and immunohistochemistry at days 7, 10, and 12.Results: Exogenous MMP-9, at the level found within chronic wounds, delayed wound healing in this animal model. By 7 days, wounds in the MMP-9–injected group were 12% larger than control wounds (P = .008). By day 12, wounds in the MMP-9–injected group were 25% larger than those of the control group (P = .03). Histologic examination shows that high levels of active MMP-9–impaired epithelial migrating tongues (P = .0008). Moreover, consistent with elevated MMP-9, the collagen IV in the leading edge of the epithelial tongue was diminished.Conclusion: MMP-9 appears to directly delay wound healing. Our data suggests that this may occur through interference with re-epithelialization. We propose that MMP-9 interferes with the basement membrane protein structure, which in turn impedes keratinocyte migration, attachment, and the reestablishment of the epidermis.

The utility of [11C] dihydrotetrabenazine positron emission tomography scanning in assessing β-cell performance after sleeve gastrectomy and duodenal-jejunal bypass

2009-10-14

Background: The aim of this study was to evaluate the effect of sleeve gastrectomy (SG) and duodenal-jejunal bypass (DJB) on glucose homeostasis and to evaluate the utility of positron emission tomography (PET) scanning for assessing β-cell mass.Methods: Goto-Kakizaki rats were divided into 4 groups: control, sham, SG, or DJB. Oral glucose tolerance, insulin, and glucagon-like peptide-1 (GLP-1) were measured before and after surgery. Before and 90 days after treatment, [11C] DTBZ micro PET scanning was performed.Results: The control and sham animals gained more weight compared with SG and DJB animals (P ≤ .05). Compared with control animals, the glucose area under the curve was lower in DJB animals 30 and 45 days after operations (P ≤ .05). At killing, GLP-1 levels were greater in the DJB group compared with sham and SG (P ≤ .05), whereas insulin levels were greater in both DJB and SG compared with sham (P ≤ .05). With PET scanning, the 90-day posttreatment mean vesicular monoamine transporter type 2 binding index was greatest in the DJB animals (2.45) compared with SG (1.17), both of which were greater than baseline control animals (0.81).Conclusion: In type 2 diabetic rodents, DJB leads to improved glucose homeostasis and an increase in VMAT2 density as measured by PET scanning.

Response to “Cancer care in the pediatric surgical patient: A paradigm to abolish volume-outcome disparities in surgery”

Elvira C. van Dalen, Renée L. Mulder, Huib N. Caron, Leontien C.M. Kremer — 2009-09-23

To the Editors: We read with interest the article by Gutierrez et al, who addressed the important question of whether children diagnosed with neuroblastoma or Wilms tumor treated at a high-volume center had a better survival than children treated at a low-volume center. Gutierrez et al defined high-volume centers as centers that cumulatively treated more than approximately 50% of patients for each diagnosis; the remainder were classified as low-volume centers. For both tumors, no statistically significant differences (ie, P > .05) in 5- or 10-year survival and risk of death between high-volume centers and low-volume centers were identified. The authors conclude that, for children with neuroblastoma and Wilms tumor, survival is unrelated to the hospital surgical volume and that care models for pediatric cancer patients may provide insight into ways to improve the treatment of adult cancer patients.

Operative management of solitary intra-abdominal recurrence of hepatocellular carcinoma

2009-11-30

To the Editors: The recent strategies of treatments for local recurrent hepatocellular carcinoma (HCC), including radiofrequency ablation, percutaneous ethanol injection, and transcatheter arterial chemoembolization, have resulted good control of intrahepatic recurrence and prolonged the survival of patients with HCC. In contrast, the appropriate treatment of extrahepatic recurrence remains controversial, especially operative resection. We report 5 patients who underwent resection for solitary intra-abdominal, extrahepatic metastases after a curative hepatectomy 5–32 months previously. Three were males and 2 were females (age range, 40–82 years); their recurrent disease intra-abdominally was in stomach, adrenal, diaphragm (n=1 each), or in lymph nodes (n=2). Resection of these apparent solitary recurrences led to relatively good results with mean survival of 40 months. Three patients died from recurrence 17, 24, and 49 months after resection. The remaining 2 patients are still alive without further recurrence, and 1 survives >8 years.

An organized response to resident work-hours restrictions

R. Matthew Walsh — 2009-12-11

To the Editors: I would compliment the editors for compiling the series of articles regarding resident work hour restrictions. In aggregate, they demonstrate a thoughtful and impassioned response of the entire organized surgical community to the issues of resident training. I would find it difficult to imagine that the readership of Surgery would not overwhelmingly concur with the multiple concerns for patient care and future of the profession. The question is, who else is listening? The perception is, certainly not the Institute of Medicine. When the ACS Task Force presents its concerns to the current work hour restriction in March of 2008 and the IOM issues more draconian recommendations in December of 2008, it is easy to conclude that our input has been marginalized or ignored. The question for Dr Britt is, what recourse do we have within the ACGME to continue ownership of the surgical training program? Should no recourse exist, then the most erudite position paper risks falling on deaf ears. What is to prevent the ACGME from heading toward the European model of a 50 or 40 hour work-week should they deem it desirable?

2010-02-01

Surgery

Cover 1

Contribution of biologically derived nanoparticles to disease

Prevalence and clinical relevance of pathological hepatic changes occurring after neoadjuvant chemotherapy for colorectal liver metastases

Chemotherapy liver injury

Prognostic impact of the width of subserosal invasion in gastric cancer invading the subserosal layer

Impact of lymphovascular invasion in patients with stage I gastric cancer

Repair using the pectoralis major muscle flap for anastomotic leakage after esophageal reconstruction via the subcutaneous route

Fast-track surgery after laparoscopic colorectal surgery: Is it feasible in a general surgery unit?

Significant parameters for surgery in adult intussusception

The value of various definitions of intrathoracic goiter for predicting intra-operative and postoperative complications

Substernal goiter: What is in a definition?

Occult lymph node metastases in neck level V in papillary thyroid carcinoma

Impact of sleep deprivation on medium-term psychomotor and cognitive performance of surgeons: Prospective cross-over study with a virtual surgery simulator and psychometric tests

The performance effects of sleep deprivation and fatigue

Sleep deprivation and surgical performance: A difficult simulation

Decreased collagen and increased matrix metalloproteinase-13 in experimental abdominal aortic aneurysms in males compared with females

Common femoral artery endarterectomy for occlusive disease: An 8-year single-center prospective study

Tailored neurectomy for treatment of postherniorrhaphy inguinal neuralgia

Roux-en-Y gastric bypass reverses renal glomerular but not tubular abnormalities in excessively obese diabetics

Antiangiogenic response after 70% hepatectomy and its relationship with hepatic regeneration and angiogenesis in rats

Matrix metalloproteinase-9 delays wound healing in a murine wound model

The utility of [11C] dihydrotetrabenazine positron emission tomography scanning in assessing β-cell performance after sleeve gastrectomy and duodenal-jejunal bypass

Response to “Cancer care in the pediatric surgical patient: A paradigm to abolish volume-outcome disparities in surgery”

Operative management of solitary intra-abdominal recurrence of hepatocellular carcinoma

An organized response to resident work-hours restrictions

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