Category Archives: Perioperative Care

Can vein diameter predict arteriovenous fistula maturation?

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One discussion this week included the relationship between vein size and fistula failure.

Reference: Bashar K, et al. The role of venous diameter in predicting arteriovenous fistula maturation: when not to expect an AVF to mature according to pre-operative vein diameter measurements? A best evidence topic. International Journal of Surgery. 2015 Mar;15:95-99. doi: 10.1016/j.ijsu.2015.01.035.

Summary: This best evidence topic was investigated according to a described protocol, and asked the question: what is the minimal vein diameter that can successfully predict maturation of an arteriovenous fistula (AVF) in patients undergoing dialysis?

The search retrieved 804 papers, of which 5 represented the best evidence to answer the clinical question. All studies assessed the association between successful AVF maturation and the size of vein used.

Highlighted findings:

  1. The strongest evidence came from a non-randomised controlled follow-up study in which 76% of fistulas created using >2 mm cephalic vein successfully matured compared to 16% when the vein measured ≤2 mm.
  2. Another prospective, multicentre study showed 65% successful maturation using veins >4 mm compared to 45% with veins < 3 mm. Vein diameter was found to be an independent predictor of maturation in multivariate regression analysis in two retrospective observational studies.
  3. A retrospective observational study found that using venous measurements of ≥2.5 mm following tourniquet application resulted in more fistulas been created that would have otherwise been denied based on venous ultrasound mapping.
  4. Routine use of tourniquet makes it possible to form AVFs in patients who otherwise would have been rejected. One study showed good results from using a transposed BBAVF when a BCAVF was deemed inappropriate following US.

In conclusion, a vein diameter of <2.5 mm should be considered inadequate for formation of an AVF, particularly if those measurements remain unchanged following the use of tourniquet.

The timing and accuracy of SLNB for nodal management after NAC

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One discussion this week included nodal management after neoadjuvant chemotherapy (NAC).

Reference: Pilewskie M and Morrow M. Axillary nodal management following neoadjuvant chemotherapy. JAMA Oncology. 2017 Apr 1;3(4):549-555.

Summary: The increasing use of NAC has raised questions about the optimal approach to the axilla, including accuracy and timing of sentinel lymph node biopsy (SLNB) in patients who are clinically node negative (cN0) at presentation, use of NAC to avoid axillary lymph node dissection (ALND) in patients presenting with node-positive disease, and the relative importance of pre-and post-NAC stage in predicting the risk of locoregional recurrence (LRR).

The decrease in nodal metastases in cN0 patients undergoing post-NAC axillary staging and the increasing rates of pCR in the breast in patients treated with current chemotherapy regimens led to the study of SLNB among patients presenting with cN+ disease. Table 3 (below) summarizes data from three prospective, multi-institutional trials assessing the accuracy of SLNB after NAC among node-positive patients.

SLNB

The authors conclude: NAC reduces the need for ALND, and SLNB is an accurate
method of determining nodal status post NAC. The demonstration that SLNB accurately stages the axilla after NAC regardless of the presenting nodal stage (cN0, cN1) provides an important rationale for the use of NAC for axillary downstaging in patients who are candidates for breast-conserving surgery at presentation or who desire mastectomy. SLN identification rates and FNRs in those who are cN0 are similar to those seen with initial SLN surgery, and nodal recurrence after a negative SLNB is uncommon.

 

Additional Reading: Boughey JC, et al. Sentinel lymph node surgery after neoadjuvant chemotherapy in patients with node-positive breast cancer: the ACOSOG Z1071 (Alliance) clinical trial. JAMA. 2013 Oct 9;310(14):1455-1461. doi:10.1001/jama.2013.278932.

Restrictive vs liberal red-cell transfusion strategy: the Transfusions Requirements in Critical Care (TRICC) trial

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One discussion this week included the TRICC trial.

Reference: Herbert PC, et al…the Transfusion Requirements in Critical Care Investigators for the Canadian Critical Care Trials Group. A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care. NEJM. 1999 Feb 11;340(6):409-417.

Summary:  The aim of the study was to determine whether a restrictive strategy of red-cell transfusion and a liberal strategy produced equivalent results in critically ill patients, we compared the rates of death from all causes at 30 days and the severity of organ dysfunction.

Methods: Between 1994 and 1997, the trial enrolled 838 critically ill patients with euvolemia after initial treatment who had hemoglobin concentrations of less than 9.0 g per deciliter within 72 hours after admission to the intensive care unit and randomly assigned 418 patients to a restrictive strategy of transfusion, in which red cells were transfused if the hemoglobin concentration dropped below 7.0 g per deciliter and hemoglobin concentrations were maintained at 7.0 to 9.0 g per deciliter, and 420 patients to a liberal strategy, in which transfusions were given when the hemoglobin concentration fell below 10.0 g per deciliter and hemoglobin concentrations were maintained at 10.0 to 12.0 g per deciliter.

Results: The use of a threshold for red-cell transfusion as low as 7.0 g of hemoglobin per deciliter, combined with maintenance of hemoglobin concentrations in the range of 7.0 to 9.0 g per deciliter, was at least as effective as and possibly superior to a liberal transfusion strategy (threshold, 10.0 g per deciliter; maintenance range, 10.0 to 12.0) in critically ill patients with normovolemia. There was a trend toward decreased 30-day mortality among patients who were treated according to the restrictive transfusion strategy. The significant differences in mortality rates during hospitalization, rates of cardiac complications, and rates of organ dysfunction all favored the restrictive strategy.

TRICC trial

Overall, 30-day mortality was similar in the two groups (18.7 percent vs. 23.3 percent, P= 0.11). However, the rates were significantly lower with the restrictive transfusion strategy among patients who were less acutely ill — those with an Acute Physiology and Chronic Health Evaluation II score of < or =20 (8.7 percent in the restrictive-strategy group and 16.1 percent in the liberal-strategy group; P=0.03) — and among patients who were less than 55 years of age (5.7 percent and 13.0 percent, respectively; P=0.02), but not among patients with clinically significant cardiac disease (20.5 percent and 22.9 percent, respectively; P=0.69). The mortality rate during hospitalization was significantly lower in the restrictive-strategy group (22.3 percent vs. 28.1 percent, P=0.05).

Conclusion:  On the basis of the trial’s results, the authors recommend that critically ill patients receive red-cell transfusions when their hemoglobin concentrations fall below 7.0 g per deciliter and that hemoglobin concentrations should be maintained between 7.0 and 9.0 g per deciliter. The diversity of the patients enrolled in this trial and the consistency of the results suggest that these conclusions may be generalized to most critically ill patients, with the possible exception of patients with active coronary ischemic syndromes.

 

Enterocutaneous fistulas: causes, management, and Emory authors

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One discussion this week involved enterocutaneous fistulas.

Reference: Haak CI, Galloway JR, Srinivasan J. Enterocutaneous fistulas: a look at causes and management. Current Surgery Reports. 2014 Oct;2:71.

Summary: Despite advances in medical technology and surgical care, the management of enterocutaneous fistulas (ECF) remains one of the most challenging problems faced by physicians. Success depends on an expert multidisciplinary team, access to long-term enteral and parenteral nutrition support, advanced wound care, optimal medical management and meticulous, methodical, surgical decision-making and technique.

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Graft reconstruction in pancreaticoduodenectomy: outcomes and survival

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One discussion this week included use of prosthetic graft reconstruction …

Reference: Chu CK, et al. Prosthetic graft reconstruction after portal vein resection in pancreaticoduodenectomy: a multicenter analysis. Journal of the American College of Surgeons. 2010 Sep;211(3):316-324. doi: 10.1016/j.jamcollsurg.2010.04.005

Summary: Use of prosthetic grafts for reconstruction after portal vein (PV) resection during pancreaticoduodenectomy is controversial. This paper (by Emory authors) review 33 patients who underwent pancreaticoduodenectomy (PD) with vein resection and reconstruction using PTFE grafts between 1994 and 2009. Patient, operative, and outcomes variables were studied. Graft patency and survival were assessed using the Kaplan-Meier technique.

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Foley or no Foley? Criteria for perioperative Foley placement

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One discussion this week included the use of Foley catheters.

Reference: Meddings J, et al. Michigan Appropriate Periopeartive (MAP) criteria for urinary catheter use in common general and orthopaedic surgeries: results obtained using the RAND/UCLA Appropriateness Method. BMJ Quality & Safety. 2019 Jan;28(1):56-66. doi:10.1136/bmjqs-2018-008025

Summary: Indwelling urinary catheters are commonly used for patients undergoing general and orthopaedic surgery. Despite infectious and non-infectious harms of urinary catheters, there is limited guidance available to surgery teams regarding appropriate perioperative catheter use.

Meddings et al (2019) used the RAND Corporation/University of California Los Angeles (RAND/UCLA) Appropriateness Method 21 to formally rate the appropriateness of urinary catheter placement and timing for removal across routine general and
orthopaedic surgical procedures in adults, as rated by clinicians in different clinical settings across the US and informed by the available literature involving perioperative urinary catheter use.

foley

(Meddings et al, 2019, p.61)

Adjuvant chemotherapy for rectal cancer: The PROCTOR-SCRIPT trial

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A discussion this week included adjuvant chemotherapy for rectal cancer after neoadjuvant and surgery.

Reference: Breugom AJ, et al. Adjuvant chemotherapy for rectal cancer patients treated with preoperative (chemo)radiotherapy and total mesorectal excision: a Dutch Colorectal Cancer Group (DCCG) randomized phase III trial. Annals of Oncology. 2015 Apr;26(4):696-701. doi:10.1093/annonc/mdu560.

Summary: Locoregional recurrence rates and survival have significantly
improved with the introduction of total mesorectal excision (TME) for patients with rectal cancer. The addition of preoperative radiotherapy to TME surgery resulted in a more than 50% decrease in locoregional recurrences. However, the combination of preoperative (chemo)radiotherapy and TME surgery did not improve overall or disease-free survival.  Up to 30% of all patients treated with curative intent for localized rectal cancer will develop distant metastases, and distant metastases are still the main cause
of death after rectal cancer.

A multicentre, randomized phase III trial, PROCTOR-SCRIPT, was conducted to investigate the value of adjuvant chemotherapy with fluoropyrimidine monotherapy after preoperative (chemo)radiotherapy and TME surgery. The primary outcome was overall survival. Secondary outcomes were disease-free survival, overall recurrence rate, and locoregional and distant recurrence rate separately.

METHODS: Patients from 52 hospitals were recruited. Those with histologically proven stage II or III rectal adenocarcinoma were randomly assigned to observation (n=221) or adjuvant chemotherapy (n=216) after preoperative (chemo)radiotherapy and TME. Radiotherapy consisted of 5 × 5 Gy. Chemoradiotherapy consisted of 25 × 1.8-2 Gy combined with 5-FU-based chemotherapy. Adjuvant chemotherapy consisted of 5-FU/LV (PROCTOR) or eight courses capecitabine (SCRIPT). Randomization was based on permuted blocks of six, stratified according to centre, residual tumour, time between last irradiation and surgery, and preoperative treatment. The primary end point was overall survival.

RESULTS: Between 1 March 2000 and 1 January 2013, 470 patients were included, of whom 33 were incorrectly randomized. Therefore, 437 patients (309 Dutch and 128 Swedish patients) were eligible for analyses. The trial was finally closed due to poor patient accrual without reaching the intended inclusion.

  • Survival: A total of 95 patients died. Five-year overall survival was 79.2% in the observation group and 80.4% in the chemotherapy group.
  • Disease-free survival: No statistically significant difference in disease-free survival was
    observed. Five-year disease-free survival was 55.4% for the observation group and 62.7% for the chemotherapy group.
  • Recurrences: In total, there were 157 recurrences. At 5 years, the cumulative incidence for overall recurrences was 40.3% in the observation group and 36.2% in the chemotherapy group.
  • Locoregional recurrences: The 5-year cumulative incidence for locoregional recurrences was 7.8% in the observation group versus 7.8% in the chemotherapy group. This amounted to 38.5% and 34.7%, respectively, for distant recurrences.

CONCLUSION: The PROCTOR-SCRIPT trial could not demonstrate a significant benefit of adjuvant chemotherapy with fluoropyrimidine monotherapy regarding overall survival, disease-free survival, and recurrence rates after preoperative (chemo)radiotherapy and TME surgery in ypTNM stage II and III rectal cancer patients. However, this trial did not complete planned accrual.